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&EPA Method 1669: Sampling Ambient
Water for Trace Metals at EPA Water
Quality Criteria Levels
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Method 1669
Acknowledgements
This sampling method was prepared under the direction of William A. Telliard of the Engineering and
Analysis Division (BAD) within the U.S. Environmental Agency's (EPA's) Office of Science and
Technology (OST). This sampling method was prepared under EPA Contract 68-C3-0337 by the
DynCorp Environmental Programs Division, with assistance from Interface, Inc. ;
The following researchers contributed to the philosophy behind this sampling method. Their
contribution is gratefully acknowledged:
Shier Berman, National Research Council, Ottawa, Ontario, Canada;
Nicholas Bloom, Frontier Geosciences Inc, Seattle, Washington;
Eric Crecelius, Battelle Marine Sciences Laboratory, Sequim, Washington;
Russell Flegal, University of California/Santa Cruz, California;
Gary Gill, Texas A&M University at Galveston, Texas;
Carlton Hunt and Dion Lewis, Battelle Ocean Sciences, Duxbury, Massachusetts;
Carl Watras, Wisconsin Department of Natural Resources, Boulder Junction, Wisconsin
Additional support was provided by Ted Martin of the EPA Office of Research and Development's
Environmental Monitoring Systems Laboratory in Cincinnati, Ohio and by Arthur Horowitz of the U.S.
Geological Survey.
This version of the method was prepared after observations of sampling teams from the University of
California at Santa Cruz, the Wisconsin Department of Natural Resources, the U.S. Geological Survey,
and Battelle Ocean Sciences. The assistance of personnel demonstrating the sampling techniques used
by these institutions is gratefully acknowledged.
Disclaimer
This sampling method has been reviewed and approved for publication by the Analytical Methods
Staff within the Engineering and Analysis Division of the U.S. Environmental Protection Agency.
Mention of trade names or commercial products does not constitute endorsement or recommendation
for use.
Further Information
For further information, contact:
W.A. Telliard
Engineering and Analysis Division (4303)
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Phone: 202/260-7134
Fax: 202/260-7185
April 1995
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Method 1669
Introduction
This sampling method was designed to support water quality monitoring programs authorized under
the Clean Water Act. Section 304(a) of the Clean Water Act requires EPA to publish water quality
criteria that reflect the latest scientific knowledge concerning the physical fate (e.g., concentration and
dispersal) of pollutants, the effects of pollutants on ecological and human health, and the effect of
pollutants on biological community diversity, productivity, and stability.
Section 303 of the Clean Water Act requires states to set a water quality standard for each body of
water within its boundaries. A state water quality standard consists of a designated use or uses of a
waterbody or a segment of a waterbody, the water quality criteria that are necessary to protect the
designated use or uses, and an antidegradation policy. These water quality standards serve two
purposes: (1) they establish the water quality goals for a specific waterbody, and (2) they are the basis
for establishing water quality-based treatment controls and strategies beyond the technology-based
controls required by Sections 301(b) and 306 of the Clean Water Act.
In defining water quality standards, the state may use narrative criteria, numeric criteria, or both.
However, the 1987 amendments to the Clean Water Act required states to adopt numeric criteria for
toxic pollutants (designated in Section 307(a) of the Act) based on EPA Section 304(a) criteria or
other scientific data, when the discharge or presence of those toxic pollutants could reasonably be
expected to interfere with designated uses.
In some cases, these water quality criteria are as much as 280 times lower than those achievable using
existing EPA methods and required to support technology-based permits. Therefore, this sampling
method, and the analytical methods referenced in Table 1 of this document, were developed by EPA to
specifically address state needs for measuring toxic metals at water quality criteria levels, when such
measurements are necessary to protect designated uses in state water quality standards. The latest
criteria published by EPA are those listed in the National Toxics Rule (57 FR 60848). This rule
includes water quality criteria for 13 metals, and it is these criteria on which this sampling method and
the referenced analytical methods are based.
In developing these methods, EPA found that one of the greatest difficulties in measuring pollutants at
these levels was precluding sample contamination during collection, transport, and analysis. The
degree of difficulty, however, is highly dependent on the metal and site-specific conditions. This
method, therefore, is designed to provide the level of protection necessary to preclude contamination in
nearly all situations. It is also designed to provide the procedures necessary to produce reliable results
at the lowest possible water quality criteria published by EPA. In recognition of the variety of
situations to which this method may be applied, and in recognition of continuing technological
advances, the method is performance-based. Alternative procedures may be used, so long as those
procedures are demonstrated to yield reliable results.
Requests for additional copies of this method should be directed to:
U.S. EPA NCEPI
11029 Kenwood Road
Cincinnati, OH 45242
513/489-8190
April 1995
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Method 1669
Note: This document is intended as guidance only. Use of the terms "must," "may," and
"should" are included to mean that EPA believes that these procedures must, may, or should be
followed in order to produce the desired results when using this guidance. In addition, the
guidance is intended to be performance-based, in that the use of less stringent procedures may
be used so long as neither samples nor blanks are contaminated when following those modified
procedures. Because the only way to measure the performance of the modified procedures is
through the collection and analysis of uncontaminated blank samples in accordance with this
guidance and the referenced methods, it is highly recommended that any modifications be
thoroughly evaluated and demonstrated to be effective before field samples are collected.
IV
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Method 1669
Sampling Ambient Water for Determination of Metals at
EPA Water Quality Criteria Levels
1.0 Scope and Application
1.1 This method is for the collection and filtration of ambient water samples for subsequent
determination of total and dissolved metals at the levels listed in Table 1. It is designed to
support the implementation of water quality monitoring and permitting programs administered
under the Clean Water Act.
1.2 This method is applicable to the metals listed below and other metals, metals species, and
elements amenable to determination at trace levels.
Analyte
Antimony
Arsenic
Cadmium
Chromium (III)
Chromium (IV)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Symbol
(Sb)
(As)
(Cd)
Cr+3
Cr+6
(Cu)
(Pb)
(Hg)
(Ni)
(Se)
(Ag)
(Tl)
(Zn)
Chemical Abstract Services
Registry Number (CASRN)
7440-36-0
7440-38-2
7440-43-9
16065-83-1
18540-29-9
7440-50-8
7439-92-1
7439-97-6
7440-02-0
7782-49-2
7440-22-4
7440-28-0;
7440-66-6
1.3 This method is accompanied by the 1600 series methods listed in Table 1. These methods
include the sample handling, analysis, and quality control procedures necessary for reliable
determination of trace metals in aqueous samples.
1.4 This method is not intended for determination of metals at concentrations normally found in
treated and untreated discharges from industrial facilities. Existing regulations (40 CFR Parts
400-500) typically limit concentrations in industrial discharges to the mid to high part-per-
billion (ppb) range, whereas ambient metals concentrations are normally in the low part-per-
trillion (ppt) to low ppb range. This guidance is therefore directed at the collection of samples
April 1995
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Method 1669
to be measured at or near the levels listed in Table 1. Actual concentration ranges to which
this guidance is applicable will be dependent on the sample matrix, dilution levels, and other
laboratory operating conditions.
1.5 The ease of contaminating ambient water samples with the metal(s) of interest and interfering
substances cannot be overemphasized. This method includes sampling techniques that should
maximize the ability of the sampling team to collect samples reliably and eliminate sample
contamination. These techniques are given in Section 8.0 and are based on findings of
researchers performing trace metals analyses (References 14.1-14.9).
1.6 Clean and ultraclean—The terms "clean" and "ultraclean" have been used in other Agency
guidance to describe the techniques needed to reduce or eliminate contamination in trace
metals determinations. These terms are not used hi this sampling method due to a lack of
exact definitions. However, the information provided in this method is consistent with
summary guidance on clean and ultraclean techniques (Reference 14.10).
1.7 This sampling method follows the EPA Environmental Methods Management Council's
"Format for Method Documentation" (Reference 14.11).
1.8 Method 1669 is "performance-based"; i.e., an alternate sampling procedure or technique may
be used, so long as neither samples nor blanks are contaminated when following the alternate
procedures. Because the only way to measure the performance of the alternate procedures is
through the collection and analysis of uncontaminated blank samples in accordance with this
guidance and the methods referenced hi Table 1, it is highly recommended that any
modifications be thoroughly evaluated and demonstrated to be effective before field samples
are collected. Section 9.2 provides additional details on the tests and documentation required
to support equivalent performance.
1.9 For dissolved metal determinations, samples must be filtered through a 0.45-um capsule filter
at the field site. The filtering procedures are described hi this method. The filtered samples
may be preserved hi the field or transported to the laboratory for preservation. Procedures for
field preservation are detailed hi this sampling method; procedures for laboratory preservation
are provided hi the methods referenced in Table 1. Preservation requirements are summarized
in Table 2.
1.10 The procedures in this method are for use only by personnel thoroughly trained hi the
collection of samples for determination of metals at ambient water quality control levels.
2.0 Summary of Method
2.1 Before samples are collected, all sampling equipment and sample containers are cleaned in a
laboratory or cleaning facility using detergent, mineral acids, and reagent water as described in
the methods referenced hi Table 1. The laboratory or cleaning facility is responsible for
generating an acceptable equipment blank to demonstrate that the sampling equipment and
containers are free from trace metals contamination before they are shipped to the field
sampling team. An acceptable blank is one that is free from contamination below the
minimum level (ML) specified hi the referenced analytical method (Section 9.3).
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Method 1669
2.2
2.3
2.4
2.5
2.6
2.7
After cleaning, sample containers are filled with weak acid solution, individually double-
bagged, and shipped to the sampling site. All sampling equipment is also bagged for storage
or shipment. Note: EPA has found that, in some cases, it may be possible to empty the weak
acid solution from the bottle immediately prior to transport to the field site. In this case, the
bottle should be refilled with reagent water (Section 7.1).
The laboratory or cleaning facility must prepare a large carboy or other appropriate clean
container filled with reagent water (Section 7.1) for use with collection of field blanks during
sampling activities. The reagent-water-filled container should be shipped to the field site and
handled as all other sample containers and sampling equipment. At least one field blank
should be processed per site, or one per every ten samples, whichever is more frequent
(Section 9.4). If samples are to be collected for determination of trivalent chromium, the
sampling team processes additional QC aliquots are processed as described in Section 9.6.
Upon arrival at the sampling site, one member of the two-person sampling team is designated
as "dirty hands"; the second member is designated as "clean hands." All operations involving
contact with the sample bottle and transfer of the sample from the sample collection device to
the sample bottle are handled by the individual designated as "clean hands." "Dirty hands" is
responsible for preparation of the sampler (except the sample container itself), operation of any
machinery, and for all other activities that do not involve direct contact with the sample.
All sampling equipment and sample containers used for metals determinations at or near the
levels listed in Table 1 must be nonmetallic and free from any material that may contain
metals.
Sampling personnel are required to wear clean, nontalc gloves at all times when handling
sampling equipment and sample containers.
In addition to processing field blanks at each site, a field duplicate must be collected at each
sampling site, or one field duplicate per every ten samples, whichever is more frequent
(Section 9.5). Section 9 gives a complete description of quality conliol requirements.
2.8 Sampling
2.9
2.8.1 Whenever possible, samples are collected facing upstream arid upwind to minimize
introduction of contamination.
2.8.2 Samples may be collected while working from a boat or while on land.
2.8.3 Surface samples are collected using a grab sampling technique. The principle of the
grab technique is to fill a sample bottle by rapid immersion in water and capping to
minimize exposure to airborne particulate matter.
2.8.4 Subsurface samples are collected by suction of the sample into an immersed sample
bottle or by pumping the sample to the surface.
Samples for dissolved metals are filtered through a 0.45-pm capsule filter at the field site.
After filtering, the samples are double-bagged and iced immediately. Sample containers are
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Method 1669
shipped to the analytical laboratory. The sampling equipment is shipped to the laboratory or
cleaning facility for recleaning.
2.10 Acid preservation of samples is performed in the field or in the laboratory. Field preservation
is necessary for determinations of trivalent chromium. It has also been shown that field
preservation can increase sample holding times for hexavalent chromium to 30 days; therefore
it is recommended that preservation of samples for hexavalent chromium be performed in the
field. For other metals, however, the sampling team may prefer to utilize laboratory
preservation of samples to expedite field operations and to minimize the potential for sample
contamination.
2.11 Sampling activities must be documented through paper or computerized sample tracking
systems.
3.0 Definitions
3.1 Apparatus—Throughout this method, the sample containers, sampling devices, instrumentation,
and all other materials and devices used in sample collection, sample processing, and sample
analysis activities will be referred to collectively as the Apparatus.
3.2 Definitions of other terms are given in the Glossary (Section 15) at the end of this method.
4.0 Contamination and Interferences
4.1 Contamination problems in trace metals analysis
4.1.1 Preventing ambient water samples from becoming contaminated during the sampling
and analytical process is the greatest challenge faced in trace metals determinations. In
recent years, it has been shown that much of the historical trace metals data collected
in ambient water are erroneously high because the concentrations reflect contamination
from sampling and analysis rather than ambient levels (Reference 14.12). Therefore, it
is imperative that extreme care be taken to avoid contamination when collecting and
analyzing ambient water samples for trace metals.
4.1.2 There are numerous routes by which samples may become contaminated. Potential
sources of trace metals contamination during sampling include metallic or metal-
containing sampling equipment, containers, labware (e.g. talc gloves that contain high
levels of zinc), reagents, and deionized water; improperly cleaned and stored
equipment, labware, and reagents; and atmospheric inputs such as dirt and dust from
automobile exhaust, cigarette smoke, nearby roads, bridges, wires, and poles. Even
human contact can be a source of trace metals contamination. For example, it has
been demonstrated that dental work (e.g., mercury amalgam fillings) in the hiouths of
laboratory personnel can contaminate samples that are directly exposed to exhalation
(Reference 14.3).
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Method 1669
4.2 Contamination Control
4.2.1 Philosophy—The philosophy behind contamination control is to ensure that any object
or substance that contacts the sample is nonmetallic and free from any material that
may contain metals of concern.
4.2.1.1 The integrity of the results produced cannot be compromised by contamination
of samples. Requirements and suggestions for controlling sample
contamination are given in this sampling method and in the analytical methods
referenced in Table 1.
4.2.1.2 Substances in a sample or in the surrounding environment cannot be allowed
to contaminate the Apparatus used to collect samples for trace metals
measurements. Requirements and suggestions for protecting the Apparatus are
given in this sampling method and in the methods referenced in Table 1.
4.2.1.3 While contamination control is essential, personnel health and safety remain
the highest priority. Requirements and suggestions for personnel safety are
given in Section 5 of this sampling method and in the methods referenced in
Table 1.
4.2.2 Avoiding contamination—The best way to control contamination is to completely
avoid exposure of the sample and Apparatus to contamination in the first place.
Avoiding exposure means performing operations in an area, known to be free from
contamination. Two of the most important factors in avoiding/reducing sample
contamination are (1) an awareness of potential sources of contamination and (2) strict
attention to work being performed. Therefore, it is imperative that the procedures
described in this method be carried out by well trained, experienced personnel.
Documentation of training should be kept on file and readily available for review.
4.2.2.1 Minimize exposure—The Apparatus that will contact samples or blanks should
only be opened or exposed in a clean room, clean bench, glove box, or clean
plastic bag, so that exposure to atmospheric inputs is minimized. When not
being used, the Apparatus should be covered with clean plastic wrap, stored in
the clean bench or in a plastic box or glove box, or bagged in clean, colorless
zip-type bags. Minimizing the time between cleaning and use will also reduce
contamination.
4.2.2.2 Wear gloves—Sampling personnel must wear clean., nontalc gloves (Section
6.7) during all operations involving handling of the Apparatus, samples, and
blanks. Only clean gloves may touch the Apparatus. If another object or
substance is touched, the glove(s) must be changed before again handling the
Apparatus. If it is even suspected that gloves have become contaminated,
work must be halted, the contaminated gloves removed, and a new pair of
clean gloves put on. Wearing multiple layers of clean gloves will allow the
old pair to be quickly stripped with minimal disruption to the work activity.
4.2.2.3 Use metal-free Apparatus—All Apparatus used for metals determinations at the
levels listed in Table 1 must be nonmetallic and free of material that may
April 1995
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Method 1669
contain metals. When it is not possible to obtain equipment that is completely
free of the metal(s) of interest, the sample should not come into direct contact
with the equipment.
4.2.2.3.1 Construction materials—Only the following materials should
come in contact with samples: fluoropolymer (FEP, PTFE),
conventional or linear polyethylene, polycarbonate,
polysulfone, polypropylene, or ultrapure quartz. PTFE is less
desirable than FEP because the sintered material in PTFE may
contain contaminants and is susceptible to serious memory
effects (Reference 14.6). Fluoropolymer or glass containers
should be used for samples that will be analyzed for mercury
because mercury vapors can diffuse in or out of other
materials, resulting either in contamination or low-biased
results (Reference 14.3). Metal must not be used under any
circumstance. Regardless of construction, all materials that
will directly or indirectly contact the sample must be cleaned
using the procedures described in the referenced analytical
methods (see Table 1) and must be known to be clean and
metal-free before proceeding.
4.2.2.3.2 The following materials have been found to contain trace
metals and must not be used to hold liquids that come in
contact with the sample or must not contact the sample, unless
these materials have been shown to be free of the metals of
interest at the desired level: Pyrex, Kimax, methacrylate,
polyvinylchloride, nylon, and Vycor (Reference 14.6). In
addition, highly colored plastics, paper cap liners, pigments
used to mark increments on plastics, and rubber all contain
trace levels of metals and must be avoided (Reference 14.13).
4.2.2.3.3 Serialization—Serial numbers should be indelibly marked or
etched on each piece of Apparatus so that contamination can
be traced, and logbooks should be maintained to track the
sample from the container through the sampling process to
shipment to the laboratory. Chain-of-custody procedures may
also be used if warranted so that contamination can be traced
to particular handling procedures or lab personnel.
4.2.2.3.4 The Apparatus should be clean when the sampling team
receives it. If there are any indications that the Apparatus is
not clean (e.g., a ripped storage bag), an assessment ;of the
likelihood of contamination must be made. Sampling must not
proceed if it is possible that the Apparatus is contaminated. If
the Apparatus is contaminated, it must be returned to the
laboratory or cleaning facility for proper cleaning before any
sampling activity resumes.
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Method 1669
4.2.2.3.5 Details for recleaning the Apparatus between collection of
individual samples are provided in Section 10.
4.2.2.4 Avoid sources of contamination—Avoid contamination by being aware of
potential sources and routes of contamination.
4.2.2.4.1
4.2.2.4.2
4.2.2.4.3
4.2.2.4.4
Contamination by carryover—Contamination may occur when
a sample containing low concentrations of metals is processed
immediately after a sample containing relatively high
concentrations of these metals. At sites where more than one
sample will be collected, the sample known or expected to
contain the lowest concentration of metals should be collected
first with the sample containing the highest levels collected last
(Section 8.1.4). This will help miniimize carryover of metals
from high- concentration samples to low- concentration
samples. If the sampling team does; not have prior knowledge
of the waterbody, or when necessary, the sample collection
system should be rinsed with dilute acid and reagent water
between samples and followed by collection of a field blank
(Section 10.3).
Contamination by samples—Significant contamination of the
Apparatus may result when untreated effluents, in-process
waters, landfill leachates, and other samples containing mid- to
high-level concentrations of inorganic substances are processed.
As stated in Section 1, this sampling method is not intended
for application to these samples, and samples containing high
concentrations of metals must not be collected, processed, or
shipped at the same time as samples being collected for trace
metals determinations.
Contamination by indirect contact—Apparatus that may not
directly contact samples may still be a source of contamination.
For example, clean tubing placed in a dirty plastic bag may
pick up contamination from the bag and subsequently transfer
the contamination to the sample. Therefore, it is imperative
that every piece of the Apparatus that is directly or indirectly
used in the collection of ambient water samples be cleaned as
specified in the analytical method(s) referenced in Table 1.
Contamination by airborne paniculate matter—Less obvious
substances capable of contaminating samples include airborne
particles. Samples may be contaminated by airborne dust, dirt,
paniculate matter, or vapors from automobile exhaust; cigarette
smoke; nearby corroded or rusted bridges, pipes, poles, or
wires; nearby roads; and even human breath (Section 4.1.2).
Whenever possible, the sampling activity should occur as far as
possible from sources of airborne contamination (Section
April 1995
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Method 1669
8.1.3). Areas where nearby soil is bare and subject to wind
erosion should be avoided.
4 3 Interferences—Interferences resulting from samples will vary considerably from source to
source, depending on the diversity of the site being sampled. If a sample is suspected of
containing substances that may interfere in the determination of trace metals, sufficient sample
should be collected to allow the laboratory to identify and overcome interference problems.
5.0 Safety
5 1 The toxicity or carcmogenicity of the chemicals used in this method has not been precisely
determined; however, these chemicals should be treated as a potential health hazard. Exposure
should be reduced to the lowest possible level. Sampling teams are responsible for
maintaining a current awareness file of OSHA regulations for the safe handling of the
chemicals specified in this method. A reference file of Material Safety Data Sheets should
also be made available to all personnel involved in sampling. It is also suggested that the
organization responsible perform personal hygiene monitoring of each sampling team member
who uses this method and that the results of this monitoring be made available to the member.
5.2 Operating in and around waterbodies carries the inherent risk of drowning. Life jackets must
be worn when operating from a boat, when sampling in more than a few feet of water, or
when sampling in swift currents.
5 3 Collecting samples in cold weather, especially around cold water bodies, carries the risk of
hypothermia, and collecting samples in extremely hot and humid weather carries the risk of
dehydration and heat stroke. Sampling team members should wear adequate clothing for
protection in cold weather and should carry an adequate supply of water or other liquids for
protection against dehydration in hot weather.
6.0 Apparatus and Materials
Note: Brand names, suppliers, and part numbers are for illustration only and no
endorsement is implied. Equivalent performance may be achieved using apparatus
and materials other than those specified here. Meeting the performance requirements
of this method is the responsibility of the sampling team and laboratory.
6 1 All sampling equipment and sample containers must be precleaned in a laboratory or cleaning
facility, as described in the methods referenced in Table 1, before they are shipped to the field
site. Performance criteria for equipment cleaning is described hi the referenced methods. To
minimize difficulties in sampling, the equipment should be packaged and arranged to minimize
field preparation.
6.2 Materials such as gloves (Section 6.7), storage bags (Section 6.8), and plastic wrap (Section
6.9), may be used new without additional cleaning unless the results of the equipment blank
April 1995
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Method 1669
6.3
6.4
pinpoint any of these materials as a source of contamination. In this case, either a different
supplier must be obtained or the materials must be cleaned.
Sample bottles—Fluoropolymer (FEP, PTFE), conventional or linear polyethylene,
polycarbonate, or polypropylene; 500-mL or 1-L with lids. If mercury is a target analyte,
fluoropolymer or glass bottles should be used. Refer to the methods referenced in Table 'l for
bottle cleaning procedures.
6.3.1 Cleaned sample bottles should be filled with 0.1% HC1 (v/v). In some cases, it may
be possible to empty the weak acid solution from the sample bottle immediately prior
to transport to the field site. In this case, the bottle should be refilled with reagent
water (Section 7.1).
6.3.2 Whenever possible, sampling devices should be cleaned and prepared for field use in a
class 100 clean room. Preparation of the devices in the field should be done within
the glove bag (Section 6.6). Regardless of design, sampling devices must be
constructed of nonmetallic material (Section 4.2.2.3.1) and free from material that
contains metals. Fluoropolymer or other material shown not to adsorb or contribute
mercury must be used if mercury is a target analyte; otherwise, polyethylene,
polycarbonate, or polypropylene are acceptable. Commercially available sampling
devices may be used provided that any metallic or metal-containing parts are replaced
with parts constructed of nonmetallic material.
Surface sampling devices—Surface samples are collected using a grab sampling technique.
Samples may be collected manually by direct submersion of the bottle into the water or by
using a grab sampling device. Examples of grab samplers are shown in Figures 1 and 2 and
may be used at sites where depth profiling is neither practical nor necessary.
6.4.1
6.4.2
The grab sampler in Figure 1 consists of a heavy fluoropolymer collar fastened to the
end of a 2-m-long polyethylene pole, which serves to removes the sampling personnel
from the immediate vicinity of the sampling point. The collar holds the sample bottle.
A fluoropolymer closing mechanism, threaded onto the bottle, enables the sampler to
open and close the bottle under water, thereby avoiding surface microlayer
contamination (Reference 14.14). Polyethylene, polycarbonate, and polypropylene are
also acceptable construction materials unless mercury is a target analyte. Assembly of
the cleaned sampling device is as follows (refer to Figure 1):
6.4.1.1 Thread the pull cord (with the closing mechanism attached) through the guides
and secure the pull ring with a simple knot. Screw a sample bottle onto the
closing device and insert the bottle into the collar. Cock the closing plate so
that the plate is pushed away from the operator.
6.4.1.2 The cleaned and assembled sampling device should be stored in a double layer
of large, clean zip-type polyethylene bags or wrapped in two layers of clean
polyethylene wrap if it will not be used immediately.
An alternate grab sampler design is shown in Figure 2. This grab sampler is used for
discrete water samples and is constructed so that a capped clean bottle can be
submerged, the cap removed, sample collected, and bottle recapped at a selected depth
April 1995
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Method 1669
6.5
This device eliminates sample contact with conventional samplers (e.g., Niskm bottles),
thereby reducing the risk of extraneous contamination. Because a fresh bottle is used
for each sample, carryover from previous samples is eliminated (Reference 14.15).
Subsurface sampling devices—Subsurface sample collection may be appropriate in lakes and
sluggish deep river environments or where depth profiling is determined to be necessary.
Subsurface samples are collected by pumping the sample into a sample bottle. Examples ot
subsurface collection systems include the the jar system device shown in Figure 3 arjd
described in Section 6.5.1 or the continuous-flow apparatus shown in Figure 4 and described
in Section 6.5.2.
6.5.1 Jar sampler (Reference 14.14)—The jar sampler (Figure 3) is comprised of a heavy
fluoropolymer 1-L jar with a fluoropolymer lid equipped with two 1/4-m.
fluoropolymer fittings. Sample enters the jar through a short length of fluoropolymer
tubing inserted into one fitting. Sample is pulled into the jar by pumping on
fluoropolymer tubing attached to the other fitting. A thick fluoropolymer plate
supports the jar and provides attachment points for a fluoropolymer safety line and
fluoropolymer torpedo counterweight.
6511 Advantages of the jar sampler for depth sampling are (1) all wetted surfaces
are fluoropolymer and can be rigorously cleaned; (2) the sample is collected
into a sample jar from which the sample is readily recovered, and the jar can
be easily recleaned; (3) the suction device (a peristaltic or rotary vacuum
pump, Section 6.15) is located in the boat, isolated from the sampling jar; (4)
the sampling jar can be continuously flushed with sample, at sampling depth,
to equilibrate the system; and (5) the sample does not travel through long
lengths of tubing that are more difficult to clean and keep clean (Reference
14.14). In addition, the device is designed to eliminate atmospheric contact
with the sample during collection.
6 5 1.2 To assemble the cleaned jar sampler, screw the torpedo weight onto the
machined bolt attached to the support plate of the jar sampler. Attach a
section of the 1/4-in. o.d. tubing to the jar by inserting the tubing into the
fitting on the lid and pushing down into the jar until approximately 8 cm from
the bottom. Tighten the fitting nut securely. Attach the solid safety line to the
jar sampler using a bowline knot to the loop affixed to the support plate.
6.5.1.3 For the tubing connecting the pump to the sampler, tubing lengths of up to 12
m have been used successfully (Reference 14.14).
6 5 2 Continuous-flow sampler (References 14.16-14.17)-Tbis sampling system, shown in Figure 4,
consists of a peristaltic or submersible pump and one or more lengths of precleaned
fluoropolymer or styrene/ethylene/butylene/ silicone (SEES) tubing. A filter is added to the
sampling train when sampling for dissolved metals.
6521 Advantages of this sampling system include (1) all wetted surfaces are
fluoropolymer or SEES and can be readily cleaned; (2) the suction device is
located in the boat, isolated from the sample bottle; (3) the sample does not
travel through long lengths of tubing that are difficult to clean and keep clean;
10
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Method 1669
6.6
and (4) in-line filtration is possible, minimizing field handling requirements for
dissolved metals samples
6.5.2.2 The sampling team assembles the system in this field as described in Section
8.2.8. System components include an optional polyethylene pole to remove
sampling personnel from the immediate vicinity of the sampling point and the
pump, tubing, filter, and filter holder listed in Sections 6.14 and 6.15.
Field-portable glove bag-I2R, Model R-37-37H (nontalc), or equivalent. Alternately a
portable glove box may be constructed with a nonmetallic (PVC pipe or other suitable
material) frame and a frame cover made of an inexpensive, disposable, nonmetallic material
(e.g., a thin-walled polyethylene bag) (Reference 14.7).
Gloves-<;lean, nontalc polyethylene, latex, vinyl, or PVC; various lengths. Shoulder-length
gloves are needed if samples are to be collected by direct submersion of the sample bottle into
the water or when sampling for mercury.
6.7.1 Gloves, shoulder-length polyethylene—Associated Bag Co., Milwaukee WI 66-3-301
or equivalent. ' '
6.7.2 Gloves, PVC—Fisher Scientific Part No. 11-394-100B, or equivalent.
6.8 Storage bags—clean, zip-type, nonvented, colorless polyethylene (various sizes).
Plastic wrap—clean, colorless polyethylene.
6.7
6.9
6.10 Cooler—clean, nonmetallic, with white interior for shipping samples.
6.11 Ice or chemical refrigerant packs—to keep samples chilled in the cooler during shipment.
6.12 Wind suit—Pamida, or equivalent. Note: This equipment is necessary only for collection of
metals, such as mercury, that are known to have elevated atmospheric concentrations.
6.12.1 An unlined, long-sleeved wind suit consisting of pants and jacket and constructed of
nylon or other synthetic fiber is worn when sampling for mercury to prevent mercury
adsorbed onto cotton or other clothing materials from contaminating samples.
6.12.2 Washing and drying—The wind suit is washed by itself or with other wind suits only
in a home or commercial washing machine and dried in a clothes dryer The clothes
dryer must be thoroughly vacuumed, including the lint filter, to remove all traces of
lint before drying. After drying, the wind suit is folded and stored in a clean
polyethylene bag for shipment to the sample site.
6.13 Boat
6.13.1 For most situations (e.g., most metals under most conditions), the use of an existing
available boat is acceptable. A flat-bottom, Boston Whaler-type boat is preferred
because sampling materials can be stored with reduced chance of tipping
April 1995
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Method 1669
6.13.2.2
6 13 1 1 Immediately before use, the boat should be washed with water from
the sampling site away from any sampling points to remove any dust
or dirt accumulation.
6.13.1.2 Samples should be collected upstream of boat movement.
6 13 2 For mercury, and for situations in which the presence of contaminants cannot
otherwise be controlled below detectable levels, the following equipment and
precautions may be necessary:
6 13 2 1 A metal-free (e.g., fiberglass) boat, along with wooden or fiberglass
oars. Gasoline- or diesel-fueled boat motors should be avoided when
possible because the exhaust can be a source of contamination. If the
body of water is large enough to require use of a boat motor, the
engine should be shut off at a distance far enough from the sampling
point to avoid contamination, and the sampling team should manually
propel the boat to the sampling point. Samples should be collected
upstream of boat movement.
Before first use, the boat should be cleaned and stored in an area that
minimizes exposure to dust and atmospheric particles. For example,
cleaned boats should not be stored in an area that would allow
exposure to automobile exhaust or industrial pollution.
6.13.2.3 The boat should be frequently visually inspected for possible
contamination.
6 13 2 4 After sampling, the boat should be returned to the laboratory or
cleaning facility, cleaned as necessary, and stored away from any
sources of contamination until next use.
6.14 Filtration Apparatus—Required when collecting samples for dissolved metals determinations.
6.14.1 Filter—0.45-um, 15-mm diameter or larger, tortuous-path capsule filters (Reference
14.18), Gelman Supor 12175, or equivalent.
6142 Filter holder for mounting filter to the gunwale of the boat-Rod or pipe made from
' ' plastic material and mounted with plastic clamps. Note: A filter holder may not be
required if one or a few samples are to be collected. For these cases, it may only be
necessary to attach the filter to the outlet of the tubing connected to the pump.
6.15 Pump and pump apparatus-Required for use with the jar sampling system (Section 6 51) or
the continuous-flow system (Section 6.5.2). Peristaltic pump-15-V ac12-V dc mternal
battery, variable-speed, single-head, Cole-Parmer, portable, "Masterflex L/S, Catalog Na H-
07570-10 drive with Quick Load pump head, Catalog No. H-07021-24, or equivalent. (Note.
Equivalent pumps may include rotary vacuum, submersible, or other pumps free from metals
and suitable to meet the site-specific depth sampling needs.)
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Method 1669
6.15.1 Cleaning—Peristaltic pump modules do not require cleaning. However, nearly all
peristaltic pumps contain a metal head and metal controls. Touching the head or
controls necessitates changing of gloves before touching the Apparatus. If a
submersible pump is used, a large volume of sample should be pumped to clean the
stainless steel shaft (hidden behind the impeller) that comes in contact with the sample.
Pumps with metal impellers should not be used.
6.15.2 Tubing for use with peristaltic pump—SEES resin, approximately 3/8-in. i.d. by
approximately 3 ft, Cole-Farmer size 18, Cat. No. G-06464-18, or approximately 1/4-
in. i.d., Cole-Parmer size 17, Catalog No. G-06464-17, or equivalent. Tubing is
cleaned by soaking in 5-10% HC1 solution for 8-24 h, rinsing with reagent water in a
clean bench in a clean room, and drying in the clean bench by purging with mercury-
free air or nitrogen. After drying, the tubing is double-bagged in clear polyethylene
bags, serialized with a unique number, and stored until use.
6.15.3 Tubing for connection to peristaltic pump tubing—fluoropolymer, 3/8- or 1/4-in. o.d.,
in lengths as required to reach the point of sampling. If s£impling will be at some
depth from the end of a boom extended from a boat, sufficient tubing to extend to the
end of the boom and to the depth will be required. Cleaning of the fluoropolymer can
be the same as cleaning the tubing for the rotary vacuum pump (Section 6.15.1.2). If
necessary, more agressive cleaning (e.g., concentrated nitric acid) may be used.
6.15.4 Batteries to operate submersible pump—12-V, 2.6- amp, gel cell, YUASA NP2.6-12,
or equivalent. A 2-amp fuse connected at the positive battery terminal is strongly
recommended to prevent short circuits from overheating the battery. A 12-V, lead-acid
automobile or marine battery may be more suitable for extensive pumping.
6.15.5 Tubing connectors—appropriately sized PVC, clear polyethylene, or fluoropolymer
"barbed" straight connectors cleaned as the tubing above. Used to connect multiple
lengths of tubing.
6.16 Carboy for collection and storage of dilute waste acids used to store bottles.
6.17 Apparatus for field preservation of aliquots for trivalent chromium determinations
6.17.1 Fluoropolymer forceps,, 1-L fluoropolymer jar, and 30-mL fluoropolymer vials with
screw-caps (1 vial per sample and blank). It is recommended that 1 mL of ultrapure
nitric acid (Section 7.3) be added to each vial prior to transport to the field to simplify
field handling activities (See Section 8.4.4.6).
6.17.2 Filters—0.4-um, 47-mm polycarbonate Nucleopore (or equivalent). Filters are cleaned
as follows. Fill a 1-L fluoropolymer jar approximately two-thirds full with 1-N nitric
acid. Using fluoropolymer forceps, place individual filters in the fluoropolymer jar.
Allow the filters to soak for 48 h. Discard the acid, and rinse five times with reagent
water. Fill the jar with reagent water, and soak the filters for 24 h. Remove the filters
when ready for use, and using fluoropolymer forceps, place them on the filter
apparatus (Section 6.17.3).
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Method 1669
6.17.3 Vacuum filtration apparatus—Millipore 47-mm size, or equivalent, vacuum pump and
power source (and extension cords, if necessary) to operate the pump.
6.17.4 Eppendorf auto pipet and colorless pipet tips (100-1000 pL)
6.17.5 Wrist-action shaker—Burrel or equivalent.
6.17.6 Fluoropolymer wash bottles—one filled with reagent water (Section 7.1) and one filled
with high- purity 10% HC1 (Section 7.4.4), for use in rinsing forceps and pipet tips.
7.0 Reagents and Standards
7.1 Reagent water—water in which the analytes of interest and potentially interfering substances
are not detected at the Method Detection Limit (MDL) of the analytical method used for
analysis of samples. Prepared by distillation, deionization, reverse osmosis, anodic/cathodic
stripping voltammetry, or other techniques that remove the metal(s) and potential interferent(s).
A large carboy or other appropriate container filled with reagent water must be available for
the collection of field blanks.
7.2 Nitric acid, dilute, trace-metal grade—Shipped with sampling kit for cleaning equipment
between samples.
7.3 Sodium hydroxide—Concentrated, 50% solution for use when field-preserving samples for
hexavalent chromium determinations (Section 8.4.5).
7.4 Reagents for field-processing aliquots for trivalent chromium determinations
7.4.1 Nitric acid, ultrapure—For use when field-preserving samples for trivalent chromium
determinations (Sections 6.17 and 8.4.4).
7.4.2 Ammonium iron (II) sulfate solution (0.01M)—Used to prepare the chromium (III)
extraction solution (Section 7.4.3) necessary for field preservation of samples for
trivalent chromium (Section 8.4.4). Prepare the ammonium iron (II) sulfate solution
by adding 3.92 g ammonium iron (II) sulfate (ultrapure grade) to a 1-L volumetric
flask. Bring to volume with reagent water. Store in a clean polyethylene bottle.
7.4.3 Chromium (DI) extraction solution—For use when field-preserving samples for
trivalent chromium determinations (Section 8.4.4). Prepare this solution by adding 100
mL of ammonium iron (II) sulfate solution (Section 7.4.2) to a 125-mL polyethylene
bottle. Adjust pH to 8 with approximately 2 mL of ammonium hydroxide solution.
Cap and shake on a wrist-action shaker for 24 h. This iron (ID) hydroxide solution is
stable for 30 days.
7.4.4 Hydrochloric acid—High-purity, 10% solution—shipped with sampling kit in
fluoropolymer wash bottles for cleaning trivalent chromium sample preservation
equipment between samples.
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Method 1669
7.4.5
7.4.6
7.4.7
Chromium stock standard solution (1000 ug/mL)—Prepared by adding 3.1 g anhydrous
chromium chloride to a 1-L flask and diluting to volume with 1% hydrochloric acid
Store in polyethylene bottle. A commercially available standard solution may be
substituted.
Standard chromium spike solution (1000 ug/L)—Used to spike sample aliquots for
matrix spike/matrix spike duplicate (MS/MSD) analysis and to prepare ongoing
precision and recovery standards. Prepared by spiking 1 mL of the chromium stock
standard solution (Section 7.4.5) into a 1-L flask. Dilute to volume with 1% HC1.
Store in a polyethylene bottle.
Ongoing precision and recovery (OPR) standard (25 ug/L)—Prepared by spiking 2.5
mL of the standard chromium spike solution (Section 7.4.6) into a 100-mL flask
Dilute to volume with 1% HC1. One OPR is required for every ten samples.
8.0 Sample Collection, Filtration, and Handling
8.1 Site selection
8.1.1
8.1.2
8.1.3
8.1.4
Selection of a representative site for surface water sampling is based on many factors
including: study objectives, water use, point source discharges, non-point source
discharges, tributaries, changes in stream characteristics, types of stream bed, stream
depth, turbulence, and the presence of structures (bridges, dams, etc.). When
collecting samples to determine ambient levels of trace metals, the presence of
potential sources of metal contamination are of extreme importance in site selection.
Ideally, the selected sampling site will exhibit a high degree of cross-sectional
homogeneity. It may be possible to use previously collected data to identify locations
for samples that are well mixed or are vertically or horizontally stratified. Since
mixing is principally governed by turbulence and water velocity, the selection of a site
immediately downstream of a riffle area will ensure good vertical mixing. Horizontal
mixing occurs in constrictions in the channel. In the absence of turbulent areas, the
selection of a site that is clear of immediate point sources, such as industrial effluents,
is preferred for the collection of ambient water samples (Reference 14.19),
To minimize contamination from trace metals in the atmosphere, ambient water
samples should be collected from sites that are as far as possible (e.g., at least several
hundred feet) from any metal supports, bridges, wires or poles. Similarly, samples
should be collected as far as possible from regularly or heavily traveled roads. If it is
not possible to avoid collection near roadways, it is advisable to study traffic patterns
and plan sampling events during lowest traffic flow (Reference 14.7).
The sampling activity should be planned to collect samples known or suspected to
contain the lowest concentrations of trace metals first, finishing with the samples
known or suspected to contain the highest concentrations. For example, if samples are
collected from a flowing river or stream near an industrial or municipal discharge the
upstream sample should be collected first, the downstream sample collected second
April 1995
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Method 1669 _
and the sample nearest the discharge collected last. If the concentrations of pollutants
is not known and cannot be estimated, it is necessary to use precleaned sampling
equipment at each sampling location.
8 2 Sample collection procedure-Before collecting ambient water samples, consideration should
be given to the type of sample to be collected, the amount of sample needed, and toe devices
to be used (grab, surface, or subsurface samplers). Sufficient sample volume should be
collected to allow for necessary quality control analyses, such as matrix spike/ matrix spike
duplicate analyses.
8.2.1 Four (4) sampling procedures are described:
8211 Section 8.2.5 describes a procedure for collecting samples directly into the
sample container. This procedure is the simplest and provides the least
potential for contamination because it requires the least amount of equipment
and handling.
8.2.1.2 Section 8.2.6 describes a procedure for using a grab sampling device to collect
samples.
8 2.1.3 Section 8.2.7 describes a procedure for depth sampling with a jar sampler.
The size of sample container used is dependent on the amount of sample
needed by the analytical laboratory.
8.2.1.4 Section 8.2.8 describes a procedure for continuous-flow sampling using a
submersible or peristaltic pump.
822 The sampling team should ideally approach the site from down current and downwind
to prevent contamination of the sample by particles sloughing off the boat or
equipment. If it is not possible to approach from both, the site should be approached
from down current if sampling from a boat or approached from downwind if sampling
on foot. When sampling from a boat, the bow of the boat should be oriented into the
current (the boat will be pointed upstream). All sampling activity should occur from
the bow.
If the samples are being collected from a boat, it is recommended that the sampling
team create a stable workstation by arranging the cooler or shipping container as a
work table on the upwind side of the boat, covering this worktable and the upwind
gunnel with plastic wrap or a plastic tablecloth, and draping the wrap or cloth over the
gunnel. If necessary, duct tape is used to hold the wrap or cloth in place.
823 All operations involving contact with the sample bottle and with transfer of the sample
from the sample collection device to the sample bottle (if the sample is not directly
collected in the bottle) are handled by the individual designated as "clean hands.
"Duly hands" is responsible for all activities that do not involve direct contact with the
sample.
Although the duties of "clean hands" and "dirty hands" would appear to be a logical separation of
responsibilities, in fact, the completion of the entire protocol may require a good deal of coordination
16
April 1995
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Method 1669
and practice. For example, "dirty hands" must open the box or cooler containing the sample bottle and
unzip the outer bag; clean hands must reach into the outer bag, open the inner bag, remove the bottle,
collect the sample, replace the bottle lid, put the bottle back into the inner bag, and zip the inner bag.
"Dirty hands" must close the outer bag and place it in a cooler.
To minimize unnecessary confusion, it is recommended that a third team member be
available to complete the necessary sample documentation (e.g., to document sampling
location, time, sample number, etc). Otherwise, "dirty hands" must perform the
sample documentation activity (Reference 14.7).
8.2.4
Extreme care must be taken during all sampling operations to minimize exposure of
the sample to human, atmospheric, and other sources of contamination. Care must be
taken to avoid breathing directly on the sample, and whenever possible, the sample
bottle should be opened, filled, and closed while submerged.
8.2.5 Manual collection of surface samples directly into the sample bottle
8.2.5.1 At the site, all sampling personnel must put on clean gloves (Section 6.7)
before commencing sample collection activity, with "clean hands" donning
shoulder-length gloves. If samples are to be analyzed for mercury, the
sampling team must also put their precleaned wind suits on at this time. Note
that "clean hands" should put on the shoulder-length polyethylene gloves
(Section 6.7.1) and both "clean hands" and "dirty hands" should put on the
PVC gloves (Section 6.7.2).
8.2.5.2 "Dirty hands" must open the cooler or storage container, remove the double-
bagged sample bottle from storage, and unzip the outer bag.
8.2.5.3 Next, "clean hands" opens the inside bag containing the sample bottle, removes
the bottle, and reseals the inside bag. "Dirty hands" then reseals the outer bag.
8.2.5.4 "Clean hands" unscrews the cap and, while holding the cap upside down,
discards the dilute acid solution from the bottle into a carboy for wastes
(Section 6.16) or discards the reagent water directly into the water body.
8.2.5.5 "Clean hands" then submerges the sample bottle, and allows the bottle to
partially fill with sample. "Clean hands" screws the cap on the bottle, shakes
the bottle several times, and empties the rinsate away from the site. After two
more rinsings, "clean hands" holds the bottle under water and allows bottle to
fill with sample. After the bottle has filled (i.e., when no more bubbles
appear), and while the bottle is still inverted so that the mouth of the bottle is
underwater, "clean hands" replaces the cap of the bottle. In this way, the
sample has never contacted the air.
8.2.5.6 Once the bottle lid has been replaced, "dirty hands" reopens the outer plastic
bag, and "clean hands" opens the inside bag, places the bottle inside it, and
zips the inner bag.
8.2.5.7 "Dirty hands" zips the outer bag.
April 1995
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Method 1669
8.2.5.8 Documentation—after each sample is collected, the sample number is
documented in the sampling log, and any unusual observations concerning the
sample and the sampling are documented.
8.2.5.9 If the sample is to be analyzed for dissolved metals, it is filtered in accordance
with the procedure described in Section 8.3.
8.2.6 Sample collection with grab sampling device—The following steps detail sample
collection using the grab sampling device shown in Figure 1 and described in Section
6.4.1. The procedure is indicative of the "clean hands/duty hands" technique that must
be used with alternative grab sampling devices such as that shown in Figure 2 and
described in Section 6.4.2.
8.2.6.1 The sampling team puts on gloves (and wind suits, if applicable). Ideally, a
sample bottle will have been preattached to the sampling device in the class
100 clean room at the laboratory. If it is necessary to attach a bottle to the
device in the field, "clean hands" performs this operation, described in Section
6.4.2, inside the field-portable glove bag (Section 6.6).
8.2.6.2 "Dirty hands" removes the sampling device from its storage container and
opens the outer polyethylene bag.
8.2.6.3 "Clean hands" opens the inside polyethylene bag and removes the sampling
device.
8.2.6.4 "Clean hands" changes gloves.
8.2.6.5 "Dirty hands" submerges the sampling device to the desired depth and pulls
the fluoropolymer pull cord to bring the seal plate into the middle position so
that water can enter the bottle.
8.2.6.6 When the bottle is full (i.e., when no more bubbles appear), "dirty hands" pulls
the fluoropolymer cord to the final stop position to seal off the sample and
removes the sampling device from the water.
8.2.6.7 "Duty hands" returns the sampling device to its large inner plastic bag, "clean
hands" pulls the bottle out of the collar, unscrews the bottle from the sealing
device, and caps the bottle. "Clean hands" and "dirty hands" then return the
bottle to its double-bagged storage as described in Sections 8.2.5.6-8.2.5.7.
8.2.6.8 Closing mechanism: "Clean hands" removes the closing mechanism from the
body of the grab sampler, rinses the device with reagent water (Section 7.1),
places it inside a new clean plastic bag, zips the bag, and places the bag inside
an outer bag held by "dirty hands." "Dirty hands" zips the outer bag and
places the double-bagged closing mechanism hi the equipment storage box.
8.2.6.9 Sampling device: "Clean hands" seals the large inside bag containing the
collar, pole, and cord and places the bag into a large outer bag held by "dirty
18
April 1995
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Method 1669
hands." "Dirty hands" seals the outside bag and places the double-bagged
sampling device into the equipment storage box.
8.2.6.10 Documentation—after each sample is collected, the sample number is
documented in the sampling log, and any unusual observations
concerning the sample and the sampling ate documented.
8.2.6.11 If the sample is to be analyzed for dissolved metals, it is filtered in
accordance with the procedures described in Section 8.3.
8.2.7 Depth sampling using a jar sampling device (Figure 3 and Section 6.5.1)
8.2.7.1 The sampling team puts on gloves (and wind suits,, if applicable) and handles
bottles as with manual collection (Sections 8.2.5.1-8.2.5.4 and 8.2.5.6-8.2.5.7).
8.2.7.2 "Dirty hands" removes the jar sampling device from its storage container and
opens the outer polyethylene bag.
8.2.7.3 "Clean hands" opens the inside polyethylene bag and removes the jar sampling
apparatus. Ideally, the sampling device will have been preassembled in a class
100 clean room at the laboratory. If, however, it is necessary to assemble the
device in the field, "clean hands" must perform this operation, described in
Section 6.5.2, inside a field-portable glove bag (Section 6.6).
8.2.7.4 While "dirty hands" is holding the jar sampling apparatus, "clean hands"
connects the pump to the to the 1/4-in. o.d. flush Line.
8.2.7.5 "Dirty hands" lowers the weighted sampler to the desired depth.
8.2.7.6 "Duty hands" turns on the pump allowing a large volume (>2 L) of water to
pass through the system.
8.2.7.7 After stopping the pump, "dirty hands" pulls up the line, tubing, and device
and places them into either a field-portable glove bag or a large, clean plastic
bag as they emerge.
8.2.7.8 Both "clean hands" and "dirty hands" change gloves.
8.2.7.9 Using the technique described in Sections 8.2.5.2-8.2.5.4, the sampling team
removes a sample bottle from storage, and "clean hands" places the bottle into
the glove bag.
8.2.7.10 "Clean hands" tips the sampling jar and dispenses the sample through
the short length of fluoropolymer tubing into the sample bottle.
8.2.7.11 Once the bottle is filled, "clean hands" replaces the cap of the bottle,
returns the bottle to the inside polyethylene bag, and zips the bag.
April 1995
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Method 1669
"Clean hands" returns the zipped bag to the outside polyethylene bag
held by "dirty hands."
8.2.7.12 "Dirty hands" zips the outside bag. If the sample is to be analyzed for
dissolved metals, it is filtered as described in Section 8.3.
8.2.7.13 Documentation—after each sample is collected, the sample number is
documented hi the sampling log, and any unusual observations
concerning the sample and the sampling are documented.
8.2.8 Continuous-flow sampling (Figure 4 and Section 6.5.2)—The continuous-flow
sampling system uses peristaltic pump (Section 6.15) to pump sample to the boat or to
shore through the SEBS-resin or PTFE tubing.
8.2.8.1 Before putting on wind suits or gloves, the sampling team removes the bags
containing the pump (Section 6.15), SEBS-resin tubing (Section 6.15.2),
batteries (Section 6.15.4), gloves (Section 6.7), plastic wrap (Section 6.9), wind
suits (Section 6.12), and, if samples are to be filtered, the filtration apparatus
(Section 6.14) from the coolers or storage containers hi which they are packed.
8.2.8.2 "Clean hands" and "duty hands" put on the wind suits and PVC gloves
(Section 6.7.2).
8.2.8.3 "Dirty hands" removes the pump from its storage bag, and opens the bag
containing the SEBS-resin tubing. •
8.2.8.4 "Clean hands" installs the tubing while "duty hands" holds the pump. "Clean
hands" immerses the inlet end of the tubing in the sample stream.
8.2.8.5 Both "clean hands" and "dirty hands" change gloves. "Clean hands" also puts
on shoulder length polyethylene gloves (Section 6.7.1).
8.2.8.6 "Dirty hands" turns the pump on and allows the pump to run for 5-10 minutes
or longer to purge the pump and tubing.
8.2.8.7 If the sample is to be filtered, "clean hands" installs the filter at the end of the
tubing, and "duty hands" sets up the filter holder on the gunwale as shown in
Figure 4.
Note: The filtration apparatus is not attached until immediately before sampling to
prevent buildup of particulates from clogging the filter.
8.2.8.8 The sample is collected by rinsing the sample bottle and cap three times and
collecting the sample from the flowing stream.
20
April 1995
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Method 1669
8.3
8.2.8.9 Documentation—after each sample is collected, the sample number is
documented in the sampling log, and any unusual observations concerning the
sample and the sampling are documented.
Sample filtration—The filtration procedure described below is used for samples collected using
the manual (Section 8.2.5), grab (Section 8.2.6), or jar (Section 8.2.7) collection systems
(Reference 14.7). In-line filtration using the continuous-flow approach is described hi Section
8.2.8.7. Because of the risk of contamination, it is recommended that samples for mercury be
shipped unfiltered by overnight courier and filtered when received at the laboratory.
8.3.1
8.3.2
8.3.3
8.3.4
8.3.5
8.3.6
8.3.7
8.3.8
8.3.9
Set up the filtration system inside the glove bag, using the shortest piece of pump
tubing as is practicable. Place the peristaltic pump immediately outside of the glove
bag and poke a small hole in the glove bag for passage of the tubing. Also, attach a
short length of tubing to the outlet of the capsule filter.
"Clean hands" removes the water sample from the inner storage bag using the
technique described in Sections 8.2.5.2-8.2.5.4 and places the sample inside the glove
bag. "Clean hands" also places two clean empty sample bottles, a bottle containing
reagent water, and a bottle for waste in the glove bag.
"Clean hands" removes the lid of the reagent water bottle and places the end of the
pump tubing in the bottle.
"Dirty hands" starts the pump and passes approximately 200 mL of reagent water
through the tubing and filter into the waste bottle. "Clean hands" then moves the
outlet tubing to a clean bottle and collects the remaining reagent water as a blank.
"Duty hands" stops the pump.
"Clean hands" removes the lid of the sample bottle and places the intake end of the
tubing in the bottle.
"Duly hands" starts the pump and passes approximately 50 mL through the tubing and
filter into the remaining clean sample bottle and then stops the pump. "Clean hands"
uses the filtrate to rinse the bottle, discards the waste sample, and returns the outlet
tube to the sample bottle.
"Dirty hands" starts the pump and the remaining sample is processed through the filter
and collected in the sample bottle. If preservation is required, the sample is acidified
at this point (Section 8.4).
"Clean hands" replaces the lid on the bottle, returns the bottle to the inside bag, and
zips the bag. "Clean hands" then places the zipped bag into the outer bag held by
"dirty hands."
"Dirty hands" zips the outer bag, and places the double-bagged sample bottle into a
clean, ice-filled cooler for immediate shipment to the laboratory.
April 1995
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Method 1669
8.3.10 Note: It is not advisable to reclean and reuse filters. The difficulty and risk associated
with failing to properly clean these devices far outweighs the cost of purchasing a new
filter.
8.4 Preservation
8.4.1 Field preservation is not necessary for dissolved metals, except for trivalent and
hexavalent chromium, provided that the sample is preserved in the laboratory and
allowed to stand for at least two days to allow the metals adsorbed to the container
walls to redissolve. Field preservation is advised for hexavalent chromium in order to
provide sample stability for up to 30 days. Mercury samples should be shipped by
overnight courier and preserved when received at the laboratory.
8.4.2 If field preservation is required, preservation must be performed in the glove bag or in
a designated clean area, with gloved hands, as rapidly as possible to preclude
particulates from contaminating the sample. For preservation of trivalent chromium,
the glove bag or designated clean area must be large enough to accommodate the
vacuum filtration apparatus (Section 6.17.3), and an area should be available for
setting up the wrist-action shaker (Section 6.17.5). It is also advisable to set up a
work area that contains a "clean" cooler for storage of clean equipment, a "dirty"
cooler for storage of "dirty" equipment, and a third cooler to store samples for
shipment to the laboratory.
8.4.3 Preservation of aliquots for metals other than trivalent and hexavalent
chromium—Using a disposable, precleaned, plastic pipet, add 5 mL of a 10% solution
of ultrapure nitric acid in reagent water per liter of sample. This will be sufficient to
preserve a neutral sample to pH <2.
8.4.4 Preservation of aliquots for trivalent chromium (References 14.8-14.9~)
8.4.4.1 Decant 100 mL of the sample into a clean polyethylene bottle.
8.4.4.2 Clean an Eppendorf pipet by pipeting 1 mL of 10% HC1 (Section (7.4.4)
followed by 1 mL of reagent water into an acid waste container. Use the
rinsed pipet to add 1 mL of chromium (HI) extraction solution (Section 7.4.3)
to each sample and blank.
8.4.4.3 Cap each bottle tightly, place in a clean polyethylene bag, and shake on a wrist
action shaker (Section 6.17.5) for 1 h.
8.4.4.4 Vacuum-filter the precipitate through a 0.4- urn pretreated filter membrane
(Section 6.17.2), using fluoropolymer forceps (Section 6.17.1) to handle the
membrane, and a 47-mm vacuum filtration apparatus with a precleaned filter
holder (Section 6.17.3). After all sample has filtered, rinse the inside of the
filter holder with approximately 15 mL of reagent water.
8.4.4.5 Using the fluoropolymer forceps, fold the membrane in half and then in
quarters, taking care to avoid touching the side containing the filtrate to any
surface. (Folding is done while the membrane is sitting on the filter holder
22
April 1995
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Method 1669
and allows easy placement of the membrane into the sample vial). Transfer
the filter to a 30-mL fluoropolymer vial. If the iluoropolymer vial was not
pre-equipped with the ultrapure nitric acid (Section 7.4.1), rinse the pipet by
drawing and discharging 1 mL of 10% HC1 followed by 1 iriL of reagent water
into a waste container, and add 1 mL of ultrapure nitric acid to the sample
vial.
8.4.4.6 Cap the vial and double-bag it for shipment to the laboratory.
8.4.4.7 Repeat steps 8.4.4.4 through 8.4.4.6 for each sample, rinsing the fluropolymer
forceps and the pipet with 10% high-purity HC1 followed by reagent water
between samples.
8.4.5 Preservation of aliquots for hexavalent chromium (Reference 14.20)
8.4.5.1 Decant 125 mL of sample into a clean polyethylene bottle.
8.4.5.2 Prepare an Eppendorf pipet by pipeting 1 mL of 10% HC1 (Section 7.4.4)
followed by 1 mL of reagent water into an acid waste container. Use the
rinsed pipet to add 1 mL NaOH to each 125-mL sample and blank aliquot.
8.4.5.3 Cap the vial(s) and double-bag for shipment to the laboratory.
9.0 Quality Assurance/Quality Control
9.1 The sampling team shall employ a strict quality assurance/ quality control (QA/QC) program.
The minimum requirements of this program include the collection of equipment blanks, field
blanks, and field replicates. It is also desirable to include blind QC samples as part of the
program. If samples will be processed for trivalent chromium determinations, the sampling
team shall also prepare method blank, OPR, and MS/MSD samples as described in Section 9.6.
9.2 The sampling team is permitted to modify the sampling techniques described in this method to
improve performance or reduce sampling costs, provided that reliable analyses of samples are
obtained and that samples and blanks are not contaminated. Each time a modification is made
to the procedures, the sampling team is required to demonstrate that the modification does not
result in contamination of field and equipment blanks. The requirements for modification are
given in Sections 9.3 and 9.4. Because the acceptability of a modification is based on the
results obtained with the modification, the sampling team must work with an analytical
laboratory capable of making trace metals determinations to demonstrate equivalence.
9.3 Equipment Blanks
9.3.1 Before using any sampling equipment at a given site, the laboratory or equipment
cleaning contractor is required to generate equipment blanks to demonstrate that the
equipment is free from contamination. Two types of equipment blanks are required:
bottle blanks and sampling equipment blanks.
April 1995
23
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Method 1669
9.3.2 Equipment blanks must be run on all equipment that will be used in the field. If, for
example, samples are to be collected using both a grab sampling device and the jar
sampling device, then an equipment blank must be run on both pieces of equipment.
9.3.3 Equipment blanks are generated in the laboratory or at the equipment cleaning
contractor's facility by processing reagent water through the equipment using the same
procedures that are used in the field (Section 8). Therefore, the "clean hands/dirty
hands" technique used during field sampling should be followed when preparing
equipment blanks at the laboratory or cleaning facility. In addition, training programs
must require must require sampling personnel to collect a clean equipment blank
before performing on-site field activities. .
9.3.4 Detailed procedures for collecting equipment blanks are given in the analytical
methods referenced hi Table 1.
9.3.5 The equipment blank must be analyzed using the procedures detailed in the referenced
analytical method (see Table 1). If any metal(s) of interest or any potentially:
interfering substance is detected in the equipment blank at the minimum level specified
in the referenced method, the source of contamination/interference must be identified
and removed. The equipment must be demonstrated to be free from the metal(s) of
interest before the equipment may be used hi the field.
9.4 Field Blank
9.4.1 To demonstrate that sample contamination has not occurred during field sampling and
sample processing, at least one (1) field blank must be generated for eveiy ten (10)
samples that are collected at a given site. Field blanks are collected before sample
collection.
9.4.2 Field blanks are generated by filling a large carboy or other appropriate container with
reagent water (Section 7.1) in the laboratory, transporting the filled container to the
sampling site, processing the water through each of the sample processing steps and
equipment (e.g., tubing, sampling devices, filters, etc.) that will be used in the field,
collecting the field blank in one of the sample bottles, and shipping the bottle to the
laboratory for analysis in accordance with the method(s) referenced hi Table 1. For
example, manual grab sampler field blanks are collected by directly submerging a
sample bottle into the water, filling the bottle, and capping. Subsurface sampler field
blanks are collected by immersing the tubing into the water and pumping water into a
sample container.
9.4.3 Filter the field blanks using the procedures described in Section 8.3.
9.4.4 If it is necessary to acid clean the sampling equipment between samples (Section 10), a
field blank should be collected after the cleaning procedures but before the next
sample is collected.
9.4.5 If trivalent chromium aliquots are processed, a separate field blank must be collected
and processed through the sample preparation steps given in Sections 8.4.4.1-8.4.4.6.
24
April 1995
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Method 1669
9.5 Field Duplicate
9.5.1 To assess the precision of the field sampling and analytical processes, at least one (1)
field duplicate sample must be collected for every ten (10) samples that are collected
at a given site.
9.5.2 The field duplicate is collected either by splitting a larger volume into two aliquots in
the glove box, by using a sampler with dual inlets that allows simultaneous collection
of two samples, or by collecting two samples in rapid succession.
9.5.3 Field duplicates for dissolved metals determinations must be processed using the
procedures in Section 8.3. Field duplicates for trivalent chromium must be processed
through the sample preparation steps given in Sections 8.4.4.1-8.4.4.6.
9.6 Additional QC for Collection of Trivalent Chromium Aliquots
9.6.1 Method blank—The sampling team must prepare one method blank for every ten or
fewer field samples. Each method blank is prepared using the steps in Sections
8.4.4.1-8.4.4.6 on a 100-mL aliquot of reagent water (Section 7.1). Do not use the
procedures in Section 8.3 to process the method blank through the 0.45-um filter
(Section 6.14.1), even if samples are being collected for dissolved metals
determinations.
9.6.2 Ongoing precision and recovery (OPR)—The sampling team must prepare one OPR
for every ten or fewer field samples. The OPR is prepared using the steps in Sections
8.4.4.1-8.4.4.6 on the OPR standard (Section 7.4.7). Do not use the procedures in
Section 8.3 to process the OPR through the 0.45-um filter (ISection 6.14.1), even if
samples are being collected for dissolved metals determinati.ons.
9.6.3 MS/MSD—The sampling team must prepare one MS and one MSD for every ten or
fewer field samples.
9.6.3.1 If, through historical data, the background concentration of the sample can be
estimated, the MS and MSD samples should be spiked at a level of 1 to 5
times the background concentration.
9.6.3.2 For samples in which the background concentration is unknown, the MS and
MSD samples should be spiked at a concentration of 25 ug/L.
9.6.3.3 Prepare the matrix spike sample by spiking a 100-mL aliquot of sample with
2.5 mL of the standard chromium spike solution (Section 7.4.6), and
processing the MS through the steps in Sections 8.4.4.1-8.4.4.6.
9.6.3.4 Prepare the matrix spike duplicate sample by spiking a second 100-mL aliquot
of the same sample with 2.5 mL of the standard chromium spike solution, and
processing the MSD through the steps in Sections 8.4.4.1-8.4.4.6.
April 1995
25
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Method 1669
9.6.3.5 If field samples are collected for dissolved metals determinations, it is
necessary to process an MS and an MSD through the 0.45-um filter as
described in Section 8.3.
10.0 Recleaning the Apparatus Between Samples
10.1 Sampling activity should be planned so that samples known or suspected to contain the lowest
concentrations of trace metals are collected first with the samples known or suspected to
contain the highest concentrations of trace metals collected last. In this manner, cleaning of
the sampling equipment between samples in unnecessary. If it is not possible to plan sampling
activity in this manner, dedicated sampling equipment should be provided for each sampling
event.
10.2 If samples are collected from adjacent sites (e.g., immediately upstream or downstream),
rinsing of the sampling Apparatus with water that is to be sampled should be sufficient.
10.3 If it is necessary to cross a gradient (i.e., going from a high-concentration sample to a low-
concentration sample), such as might occur when collecting at a second site, the following
procedure may be used to clean the sampling equipment between samples:
10.3.1 In the glove bag, and using the "clean hands/dirty hands" procedure in Section 8.2.5,
process the dilute nitric acid solution (Section 7.2) through the Apparatus.
10.3.2 Dump the spent dilute acid in the waste carboy or in the waterbody away from the
. sampling point.
10.3.3 Process 1L of reagent water through the Apparatus to rinse the equipment and discard
the spent water.
10.3.4 Collect a field blank as described in Section 9.4.
10.3.5 Rinse the Apparatus with copious amounts of the ambient water sample and proceed
with sample collection.
10.4 Procedures for recleaning trivalent chromium preservation equipment between samples are
described in Section 8.4.4.
11.0 Method Performance
Samples were collected in the Great Lakes during September-October 1994 using the
procedures in this sampling method. ;
12.0 Pollution Prevention
12.1 The only materials used in this method that could be considered pollutants are the acids used
in the cleaning of the Apparatus, the boat, and related materials. These acids are used in dilute
solutions in small amounts and pose little threat to the environment when managed properly.
26
April 1995
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Method 1669
12.2 Cleaning solutions containing acids should be prepared in volumes consistent with use to
minimize the disposal of excessive volumes of acid.
12.3 To the extent possible, the Apparatus used to collect samples should be cleaned and reused to
minimize the generation of solid waste.
13.0 Waste Management
13.1 It is the sampling team's responsibility to comply with all federal, state, and local regulations
governing waste management, particularly the discharge regulations;, hazardous waste
identification rules, and land disposal restrictions; and to protect the air, water, and land by
minimizing and controlling all releases from field operations.
13.3
For further information on waste management, consult The Waste Management Manual for
Laboratory Personnel and Less is Better— Laboratory Chemical Management for Waste
Reduction, available from the American Chemical Society's Department of Government
Relations and Science Policy, 1155 16th Street NW, Washington, DC 20036.
References
Adeloju, S.B.; Bond, A.M. "Influence of Laboratory Environment on the Precision and
Accuracy of Trace Element Analysis," Anal. Chem. 1985, 57, 1728.
Berman, S.S.; Yeats, P.A. "Sampling of Seawater for Trace Metals," CRC Reviews in
Analytical Chemistry 1985, 16.
Bloom, N.S. "Ultra-Clean Sampling, Storage, and Analytical Strategies for the Accurate
Determination of Trace Metals in Natural Waters." Presented at the 16th Annual EPA
Conference on the Analysis of Pollutants in the Environment, Norfolk, VA, May 5, 1993.
Bruland, K.W. "Trace Elements in Seawater," Chemical Oceanography 1983, 8, 157.
Nriagu, J.O.; Larson, G.; Wong, H.K.T.; Azcue, J.M. "A Protocol for Minimizing
Contamination in the Analysis of Trace Metals in Great Lakes Waters," J. Great Lakes
Research 1993, 19, 175.
Patterson C C.; Settle, D.M. "Accuracy in Trace Analysis," in National Bureau of Standards
Special Publication 422; LaFleur, P.O., Ed., U.S. Government Printing Office, Washington,
14.0
14.1
14.2
14.3
14.4
14.5
14.6
14.7 "A Protocol for the Collection and Processing of Surface-Water Samjples for Subsequent
Determination of Trace Elements, Nutrients, and Major Ions in Filtered Water"- Office of
Water Quality Technical Memorandum 94.09, Office of Water Quality, Water Resources
Division, U.S. Geological Survey, Reston, VA, Jan. 28, 1994.
14.8 Standard Operating Procedure No. 4-54, Revision 01, SOP for Concentration and Analysis of
Chromium Species in Whole Seawater; Prepared by Battelle Ocean Sciences, Duxbury MA for
the U.S. Environmental Protection Agency Office of Marine Environmental Protection Ocean
Incineration Research Program, 1987.
April 1995
27
-------
Method 1669
14.9 Cranston, R.E.; Murray, J.W. "The Determination of Chromium Species in Natural Waters,"
Anal. Chem. Acta 1978, 99, 275.
14 10 Prothro, M.G. "Office of Water Policy and Technical Guidance on Interpretation and
Implementation of Aquatic Life Metals Criteria"; EPA Memorandum to Regional Water
Management and Environmental Services Division Directors, Oct. 1, 1993.
1411 "Format for Method Documentation"; Distributed by the EPA Environmental Monitoring
Management Council, Washington, DC, Nov. 18, 1993.
14.12 Windom, H.L; Byrd, J.T.; Smith, R.G., Jr.; Huan, F. "Inadequacy of NASQAls f Data for.
Assessing Metal Trends in the Nation's Rivers," Environ. Set. Technol. 1991, 25, 1 137.
14.13 Zief, M.; Mitchell, J.W. "Contamination Control in Trace Metals Analysis," Chemical Analysis
1976, 47, Chapter 6.
14 14 Phillips H • Shafer, M.; Dean, P.; Walker, M.; Armstrong, D. "Recommendations for Trace
Ss Andysii , of Natural Waters"; Wisconsin Department of Natural Resources: Madron,
WI, May 1992.
14.15 Hunt, CD. In Manual of Biological and Geochemical Techniques in Coastal A^ 2nd Led.;
Lambert, C.E. and Oviatt, C.A., Eds.; Marine Ecosystems Research Laborato^ Gtadua e
School of Oceanography; The University of Rhode Island: Narragansett, RI, MERL Series,
Report No. 1, Chapter IV. ;
14 16 Flegal, R. Summer 1994 San Francisco Bay Cruise, apparatus and procedures witnessed and
videotaped by W. Telliard and T. Fieldsend, Sept. 15-16, 1994.
14 17 Watras, C. Wisconsin DNR procedures for mercury sampling in pristine lakes in Wisconsin,
witnessed and videotaped by D. Rushneck and L. Riddick, Sept. 9-10, 1994.
14 18 Horowitz, A.J.; Kent A.E.; Colberg, M.R. "The Effect of Membrane Filtration Artifacts on
Dissolved Trace Element Concentrations," Wat. Res. 1992, 26, 53.
14 19 Engineering Support Branch Standard Operating Procedures and Quality Assurance Manual:
14.19 protection Agency. Region IV. Environmental Services Division:
Athens, GA.
14.20 Grohse, P. Research Triangle Institute, Institute Drive, Building 6, Research Triangle Park,
NC.
14.21 Methods 1624 and 1625, 40 CFR Part 136, Appendix A.
15.0 Glossary of Definitions and Purposes
These definitions and purposes are specific to this sampling method but have been conformed
to common usage as much as possible.
28
April 1995
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Method 1669
15.1 Ambient Water—Waters in the natural environment (e.g., rivers, Lakes, streams, and other
receiving waters), as opposed to effluent discharges.
15.2 Apparatus—The sample container and other containers, filters, filter holders, labware, tubing,
pipets, and other materials and devices used for sample collection or sample preparation, and
that will contact samples, blanks, or analytical standards.
15.3 Equipment Blank—An aliquot of reagent water that is subjected in the laboratory to all
aspects of sample collection and analysis, including contact with all sampling devices and
apparatus. The purpose of the equipment blank is to determine if the sampling devices and
apparatus for sample collection have been adequately cleaned before they are shipped to the
field site. An acceptable equipment blank must be achieved before the sampling devices and
Apparatus are used for sample collection.
15.4 Field Blank—An aliquot of reagent water that is placed in a sample container in the
laboratory, shipped to the field, and treated as a sample in all respects, including contact with
the sampling devices and exposure to sampling site conditions, filtration, storage, preservation,
and all analytical procedures. The purpose of the field blank is to determine whether the field
or sample transporting procedures and environments have contaminated the sample.
15.5 Field Duplicates (FD1 and FD2)—Two identical aliquots of a sample collected in separate
sample bottles at the same time and place under identical circumstances using a duel inlet
sampler or by splitting a larger aliquot and treated exactly the same throughout field and
laboratory procedures. Analyses of FD1 and FD2 give a measure of the precision associated
with sample collection, preservation, and storage, as well as with laboratory procedures.
15.6 Matrix Spike (MS) and Matrix Spike Duplicate (MSD)—Aliquots of an environmental
sample to which known quantities of the analytes are added in the laboratory. The MS and
MSD are analyzed exactly like a sample. Their purpose is to quantify the bias and precision
caused by the sample matrix. The background concentrations of the analytes in the sample
matrix must be determined in a separate aliquot and the measured values in the MS and MSD
corrected for background concentrations.
15.7 May—This action, activity, or procedural step is optional.
15.8 May Not—This action, activity, or procedural step is prohibited.
15.9 Minimum Level (ML)—The lowest level at which the entire analytical system gives a
recognizable signal and acceptable calibration point (Reference 14.21).
15.10 Must—This action, activity, or procedural step is required.
IS'.ll Reagent Water—Water demonstrated to be free from the metal(s) of interest and potentially
interfering substances at the MDL for that metal in the referenced method or additional
method.
15.12 Should—This action, activity, or procedural step is suggested but not required.
April 1995
29
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Method 1669
15.13 Trace-metal grade—Reagents that have been demonstrated to be free from the metal(s) of
interest at the method detection limit (MDL) of the analytical method to be used for
determination of this metal(s).
Note: The term "trace-metal grade" has been used in place of "reagent grade" or
"reagent" because acids and other materials labeled "reagent grade" have been shown
to contain concentrations of metals that -will interfere in the determination of trace
metals at levels listed in Table 1.
30
April 1995
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Method 1669
Table 1
Analytical Methods, Metals, and Concentration Levels Applicable to Method 1669
Method Detection Limit as determined by 40 CFR Part 136, Appendix B
1 Method
1631
1632
1636
1637
1638
1639
1640
^N^^^^H
Technique
Oxidation/Purge &
Trap/CVAFS
Hydride AA
Ion Chromatography
CC/STGFAA
ICP/MS
STGFAA
CC/ICP/MS
^^•••^••i^^HiMB
Metal
Mercury
Arsenic
Hexavalent
Chromium
Cadmium
Lead
Antimony
Cadmium
Copper
Lead
Nickel
Selenium
Silver
Thallium
Zinc
Antimony
Cadmium
Trivalent
Chromium
Nickel
Selenium
Zinc
Cadmium
Copper
Lead
Nickel
•^••••^^•^
MDL (pgflL)1
O.OC0053
0.002
0.23
0.0074
0.03:5
0.0097
0.013
0.087
0.01.')
0.33
1.2
0.029
0.0079
0.14
1.9
0.023
0.10
0.65
0.83
0.14
0.0024
0.024
0.008 1
0.029
ML (pg/L)2
0.0002
0.005
0.5
0.02
0.1
0.02
0.1
0.2
0.05
1
5
0.1
0.02
0.5
5
0.05
0.2
2
2
0.5
0.01
0.1
0.02 1
0, |
™ Level (ML) calculated by multiplying laboratory-determined MDL by 3.18 and roundng result to nearest multiple of 1, 2,
5 10 20, 50 etc. ui accordance wnh procedures used by HAD and described in the EPA Draft National Guidance for the Permitting
M™,fl^/orc«
April 1995
31
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Method 1669
Table 2
Analytes, Preservation Requirements, and Containers
^••^••••••M
Metal
Antimony
Arsenic
Cadmium
Copper
Lead
Nickel
Selenium
Silver
Thallium
Zinc
Chromium
(HI)
Chromium
(IV)
Mercury
•^^^— ™^«^-—^— ••— ^-"
Preservation Requirements
Add 5 mL of 10% HN03 to 1-L
sample; preserve on-site or
immediately upon laboratory receipt.
Add 1 mL chromium (HI) extraction
solution to 100 mL aliquot, vacuum
filter through 0.4-um membrane, add 1
mL 10% HN03; preserve on-site
immediately after collection.
Add 50% NaOH; preserve
immediately after sample collection.
Total: Add 0.5% high-purity HC1 or
0.5% BrCl to pH < 2;
Total & Methyl: Add 0.5% high-
purity HCL; preserve on-site or
immediately upon laboratory receipt
Acceptable Containers
500-mL or 1-L fluoropolymer, conventional
or linear polyethylene, polycarbonate, or
polypropylene containers with lid
500-mL or 1-L fluoropolymer, conventional
or linear polyethylene, polycarbonate, or
polypropylene containers with lid
500-mL or 1-L fluoropolymer, conventional
or linear polyethylene, polycarbonate, or
polypropylene containers with lid
Fluoropolymer or borosilicate glass bottles
with fluoropolymer or fluoropolymer-lined
caps
m^—m*——
32
April 1995
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J
O)
c
Q.
(0
(0
A
S
(3
0)
il
O\
-------
Method 1669
Figure 2 - Grab Sampling Device
2.5cm PVC ROD
5.1 cm
PVC PIPE
PVC ROD
\
46cm
1
PVC
PLATE
IBort
HScnH
34
April 1995
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Method 1669
Figure 3 - Jar Sampling Device
Support
Htrotif N.
(Ttflon)
Ttnea
Support
11/4'
?• Surf«c«
Pump
(TtHon)
I L TtHon
Ttflon Torp*d«
April 1995
35
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Method 1669
Figure 4 - Sample Pumping System
Teflon
Tubing
C-Flex
Tubing
Peristaltic
Pump
Tubing
Adaptor
Fiberglass
Pole
Cable Ties
Filter
Cartridge
Teflon Weight
36
April 1995
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