LABORATORY DATA VALIDATION
FUNCTIONAL GUIDELINES FOR EVALUATING ORGANICS ANALYSES
Prepared for the
HAZARDOUS SITE EVALUATION DIVISION
U.S. ENVIRONMENTAL PROTECTION AGENCY
The USEPA Data Review Work Group
Scott Siders - EPA HQ - Co-Chairperson
Jeanne Hankins - EPA Region III - Co-Chairperson
Deborah Szaro - EPA Region I
Leon Lazarus - EPA Region II
Charles Sands - EPA Region III
Charles Hooper - EPA Region IV
Patrick Churilla - EPA Region V
Debra Morey - EPA Region VII
Raleigh Farlow - EPA Region X
Ruth Bleyler
Sample Management Office
Viar & Company
Compiled by
Prepared by
February 1, 1988
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TABLE OF CONTENTS
Paee
INTRODUCTION
PRELIMINARY REVIEW 3
VOLATILES AND SEMIVOLATILES PROCEDURE 4
I. Holding Times ^
II. GC/MS Tuning ^
III. Calibration g
IV. Blanks 12
V. Surrogate Recovery 14
VI. Matrix Spike/Matrix Spike Duplicate 16
VII. Field Duplicates J7
VIII. Internal Standards Performance jg
IX. TCL Compound Identification 19
X. Compound Quantitation and Reported Detection Limits 20
XI. Tentatively Identified Compounds 21
XII. System Performance 23
XIII. Overall Assessment of Data for a Case 24
PESTICIDES PROCEDURE 25
I. Holding Times 26
II. Pesticides Instrument Performance 26
III. Calibration ^ jq
IV. Blanks 33
V. Surrogate Recovery ^4
VI. Matrix Spike/Matrix Spike Duplicate 35
VII. Field Duplicates 26
VIII. Compound Identification 37
IX. Compound Quantitation and Reported Detection Limits 3g
X. Overall Assessment of Data for a Case 39
GLOSSARY A: Data Qualifier Definitions 40
GLOSSARY B: Other Terms
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LABORATORY DATA VALIDATION
FUNCTIONAL GUIDELINES FOR EVALUATING ORGANICS ANALYSES
INTRODUCTION
This document is designed to offer guidance in laboratory data evaluation and
validation. In some aspects, it is equivalent to a Standard Operating Procedure (SOP). In
other, more subjective areas, only general guidance is offered due to the complexities and
uniqueness of data relative to specific samples. These Guidelines have been updated to
include all requirements in the 10/86 Statement of Work (SOW) for Organics and 10/86 SOW
for Volatiles.
Those areas where specific SOPs are possible are primarily areas in which definitive
performance requirements are established. These areas also correspond to specific
requirements in Agency contracts. These requirements are concerned with specifications that
are not sample dependent; they specify performance requirements on matters that should be
fully under a laboratory's control. These specific areas include blanks, calibration standards,
performance evaluation standard materials, and tuning. In particular, mistakes such as
calculation and transcription errors must be rectified by resubmission of corrected data sheets.
This document is intended for technical review. Some areas of overlap between
technical review and Contract Compliance Screening (CCS) exist; however, contract
compliance is not intended to be a goal of these guidelines. It is assumed that the CCS is
available and can be utilized to assist in the data review procedure.
Some requirements are not identical for every Case or batch of samples. Requirements
for frequency of Quality Control (QC) actions are dependent on the number of samples,
sample preparation technique, time of analysis, etc. Specific Case requirements and the
impact of nonconformance must be addressed on a case by case basis; no specific guidance is
provided. For example, there is a contract requirement that a blank analysis be performed a
minimum of once every twelve hours of analysis time. This requirement must be translated
into the number of blanks required for a specific set of samples; the data reviewer may have
to consider the impact on data quality for a sample analyzed thirteen hours after a blank, in
terms of the acceptability of that particular sample.
At times, there may be an urgent need to use data which do not meet all contract
requirements and technical criteria. Use of these data does nsl constitute either a new
requirement standard or full acceptance of the data. Any decision to utilize data for which
performance criteria have not been met is strictly to facilitate the progress of projects
requiring the availability of the data. A contract laboratory submitting data which are out of
specification may be required to rerun or resubmit data even if the previously submitted data
have been utilized due to urgent program needs; data which do not meet specified
requirements are never fully acceptable. The only exception to this requirement is in the
area of requirements for individual sample analysis; if the nature of the sample itself limits
the attainment of specifications, appropriate allowances must be made. The overriding
concern of the Agency is to obtain data which are technically valid and legally defensible.
All data reviews must have, as a cover sheet, the Organic Regional Data
Assessment (ORDA) form. If mandatory actions are required, they should be specifically
noted on this form. In addition, this form is to be used to summarize overall deficiencies
requiring attention, as well as general laboratory performance and any discernible trends in
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the quality of the data. (This form is not a replacement for the data review.) Sufficient
supplementary documentation must accompany the form to clearly identify the problems
associated with a Case. The form and any attachments must be submitted to the Contract
Laboratory Program Quality Assurance Officer (CLP QAO), the Regional Deputy Project
Officer (DPO), and the Environmental Monitoring Systems Laboratory in Las Vegas
(EMSL/LV).
It is the responsibility of the data reviewer to notify the Regional DPO concerning
problems and shortcomings with regard to laboratory data. If there is an urgent requirement,
the DPO may be contacted by telephone to expedite corrective action. It is recommended
that all items for DPO action be presented at one time. In any case, the Organic Regional
Data Assessment form must be completed and submitted.
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PRELIMINARY REVIEW
In order to use this document effectively, the reviewer should have a general
overview of the Case at hand. The exact number of samples, their assigned numbers, their
matrix, and the number of laboratories involved in their analysis are essential information.
Background information on the site is helpful but often this information is very difficult to
locate. The site project officer is the best source for answers or further direction.
CCS is a source of a large quantity of summarized information. It can be used to
alert the reviewer of problems in the Case or what may be sample-specific problems. This
information may be utilized in data validation. If CCS is unavailable, those criteria affecting
data validity must be addressed by the data reviewer.
Cases routinely have unique samples which require special attention by the reviewer.
Field blanks, field duplicates, and performance audit samples need to be identified. The
sampling records should provide:
1. Project Officer for site
2. Complete list of samples with notations on
a)
sample matrix
b)
blanks*
c)
field duplicates*
d)
field spikes*
e)
QC audit sample'
f)
shipping dates
8)
labs involved
* If applicable
The chain-of-custody record includes sample descriptions and date of sampling.
Although sampling date is not addressed by contract requirements, the reviewer must take
into account lag times between sampling and shipping while assessing sample holding times.
The Case Narrative is another source of general information. Notable problems with
matrices, insufficient sample volume for analysis or reanalysis, and unusual events should be
found in the Narrative.
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VOLATILES AND SEMIVOLATILES
PROCEDURE
The requirements to be checked in validation are listed below: ("CCS" indicates that
the contractual requirements for these items will also be checked by CCS; CCS requirements
are not always the same as the data review criteria.)
I. Holding Times (CCS - Lab holding times only)
II. GC/MS Tuning
III. Calibration
o Initial (CCS)
o Continuing (CCS)
IV. Blanks (CCS)
V. Surrogate Recovery (CCS)
VI. Matrix Spike/Matrix Spike Duplicate (CCS)
VII. Field Duplicates
VIII. Internal Standards Performance (CCS)
IX. TCL Compound Identification
X. Compound Quantitation and Reported Detection Limits
XI. Tentatively Identified Compounds
XII. System Performance (CCS)
XIII. Overall Assessment of Data for a Case
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I. HOLDING TIMES
A. Objective
The objective is to ascertain the validity of results based on the holding time of the
sample from time of collection to time of analysis or sample preparation, as
appropriate.
B. Criteria
Technical requirements for sample holding times have only been established for water
matrices. The holding times for soils are currently under investigation. When the
results are available they will be incorporated into the data evaluation process. On
October 26, 1984 in Volume 49, Number 209 of the Federal Register, page 43260, the
following holding time requirements were established under 40 CFR 136 (Clean Water
Act):
Purgeables: If unpreserved, aromatic volatiles must be analyzed within 7 days
and non-aromatic volatiles must be analyzed within 14 days. If preserved with
hydrochloric acid and stored at 4*C, then both aromatic and non-aromatic
volatiles must be analyzed within 14 days.
Extractables (Includes Base/Neutrals and Acids): Both samples and extracts
must be preserved at 4*C. Samples must be extracted within 7 days and the
extract must be analyzed within 40 days.
C. Evaluation Procedure
Actual holding are established by comparing sampling date on the EPA Sample
Traffic Report with dates of analysis and/or extraction on Form I. Examine the
sample records to determine if samples were properly preserved. (If there is no
indication of preservation, it must be assumed that the samples are unpreserved.)
D. Action
If 40 CFR 136 holding times are exceeded, flag all positive results as estimated (J)
and sample quantitation limits as estimated (UJ) and document that holding times
were exceeded.
The following table illustrates when the qualifiers are to be used for volatiles:
1. If holding times are grossly exceeded, either on the first analysis or upon re-
analysis, the reviewer must use professional judgment to determine the
reliability of the data and the effects of additional storage on the sample
results. The reviewer may determine that non-detect data are unusable (R).
Matrix
Water
Preserved
No
Yes
> 7 Davs > 14 Davs
All aromatics All compounds
None All compounds
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Due to limited information concerning holding times for soil samples, it is left
to the discretion of the data reviewer to apply water holding time criteria to
soil samples.
II. GC/MS TIININft
Objective
Tuning and performance criteria are established to ensure mass resolution,
identification and, to some degree, sensitivity. These criteria are not sample specific;
conformance is determined using standard materials. Therefore, these criteria should
be met in all circumstances.
Criteria
1. Decafluorotriphenylphosphine (DFTPP)
m/z
ION ABUNDANCE CRITERIA
51
30.0 - 60.0 % of m/z 198
68
less than 2.0% of m/z 69
70
less than 2.0 % of m/z 69
127
40.0 - 60.0% of m/z 198
197
less than 1.0 % of m/z 198
198
base peak, 100% relative abundance
199
5.0 - 9.0% of m/z 198
275
10.0 - 30.0% of m/z 198
365
greater than 1.00% of m/z 198
441
present, but less than m/z 443
442
greater than 40.0% of m/z 198
443
17.0 - 23.0% of m/z 442
2. Bromofluorobenzene (BFB)
m/z
ION ABUNDANCE CRITERIA
50
15.0 - 40.0% of the base peak
75
30.0 - 60.0% of the base peak
95
base peak, 100% relative abundance
96
5.0 - 9.0% of the base peak
173
less than 2.0% of m/z 174
174
greater than 50.0% of the base peak
175
5.0 - 9.0% of m/z 174
176
greater than 95.0%, but less than 101.0% of m/z 174
177
5.0 - 9.0% of m/z 176
Note: As contracts are modified, new criteria would then apply.
Evaluation Procedure
1. Verify from the raw data that the mass calibration is correct.
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2.
Compare the data presented on each GC/MS Tuning and Mass Calibration
(Form V) with each mass listing submitted.
Ensure the following:
a. Verify that Form V is present for each 12-hour period samples are
analyzed.
b. The laboratory has not made any transcription errors.
c. The appropriate number of significant figures has been reported
(number of significant figures given for each ion in the ion abundance
criteria column).
d. The laboratory has not made any calculation errors. For example, the %
macc of m/z 443 relative to the mass of m/z 442 is calculated using the
following equation:
. , relative abundance of m/z 443 ,„n
% abundance - _ x 100
relative abundance of m/z 442
4. If possible, verify that spectra were generated using appropriate background
subtraction techniques. Since the DFTPP and BFB spectra are obtained from
chromatographic peaks that should be free from coelution problems,
background subtraction should be straightforward and designed only to
eliminate column bleed or instrument background ions. Background
subtraction actions resulting in spectral distortions for the sole purpose of
meeting the contract specifications are contrary to the quality assurance
objectives and are therefore unacceptable.
D. Action
1. If maw calibration is in error, classify all associated data as unusable (R).
2. If ion abundance criteria are not met and the data in question are needed on a
priority basis, professional judgment may be applied to determine to what
extent the data may be utilized. Guidelines to aid in the application of
professional judgment to this topic are discussed as follows:
a. DFTPP — The most critical factors in the DFTPP criteria are the
non-instrument specific requirements that are also not unduly affected
by the location of the spectrum on the chromatographic profile. The
m/z 198/199 and 442/443 ratios are critical. These ratios are based on
the natural abundances of Carbon 12 and Carbon 13 and should always
be met. Similarly, the m/z 68, 70, 197, and 441 relative abundances
indicate the condition of the instrument and the suitability of the
resolution adjustment and are very important. Note that all of the
foregoing abundances relate to adjacent ions — they are relatively
insensitive to differences in instrument design and position of the
spectrum on the chromatographic profile. For the ions at m/z 51, 127,
and 275, the actual relative abundance is not as critical. For instance,
if m/z 275 has 40% relative abundance (criteria- 10-30%) and other
criteria are met, the deficiency is minor. The relative abundance of
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m/z 365 is an indicator of suitable instrument zero adjustment. If m/z
365 relative abundance is zero, minimum detection limits may be
affected. On the other hand, if m/z 365 is present, but less than the
1% minimum abundance criteria, the deficiency is not as serious.
b. BFB — As with DFTPP, the most important factors to consider are the
empirical results that are relatively insensitive to location on the
chromatographic profile and the type of instrumentation. Therefore,
the critical ion abundance criteria for BFB are the m/z 95/96 ratio, the
174/175 ratio, the 176/177 ratio, and the 174/176 ratio. The relative
abundances of m/z 50 and 75 are of lower importance.
3. In line with the above discussion, an expansion of minus 25% of the low limit
and plus 25% of the high limit for selected ions may be appropriate. For
example, in DFTPP the m/z 51 ion abundance criteria might be expanded
from 30-60% of m/z 198 to 22-75% of m/z 198.
a. The complete expanded criteria for DFTPP and BFB are as follows:
1) Decafluorotriphenylphosphine (DFTPP) (Expanded Criteria)*
mil ION ABUNDANCE CRITERIA
51 22.0 - 75.0% of m/z 198
68 less than 2.0% of m/z 69
70 less than 2.0% of m/z 69
127 30.0 - 75.0% of m/z 198
197 less than 1.0% of m/z 198
198 base peak, J 00% relative abundance
199 5.0 - 9.0% of m/z 198
275 7.0 - 37.0% of m/z 198
365 greater than 0.75% of m/z 198
441 present, but less than m/z 443
442 greater than 30.0% of m/z 198
443 17.0 - 23.0% of m/z 442
2) Bromofluorobenzene (BFB) (Expanded Criteria)*
ffl/Z ION ABUNDANCE CRITERIA
50 11.0 - 50.0% of the base peak
75 22.0 - 75.0% of the base peak
95 base peak, 100% relative abundance
96 5.0 - 9.0% of the base peak
173 less than 2% of the base peak
174 greater than 50% of the base peak
175 5.0 - 9.0% of m/z 174
176 greater than 95%, but less than 101% of m/z 174
177 5.0 - 9.0% of m/z 176
~Note: Does NOT change contract requirements.
b. If results fall within these expanded criteria, data may be acceptable.
c. If results fall outside these expanded criteria, all data are unusable (R).
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d. These criteria do NOT establish new contract requirements. Contract
laboratories meeting expanded criteria but not meeting contract
requirements are NOT in compliance.
e. Decisions to use analytical data associated with DFTPP and BFB tunes
not meeting contract requirements should be clearly noted on the
Organic Regional Data Assessment Form.
f. If the reviewer has reason to believe that tuning criteria were achieved
using techniques that distorted or skewed the spectra, full
documentation on the tuning quality control should be obtained. If the
techniques employed are found to be at variance with accepted
practices, the quality assurance program of the laboratory may merit
evaluation.
g. It is up to the reviewer's discretion, based on professional judgment, to
flag data associated with tunes meeting expanded criteria, but not basic
criteria. If only one element falls within the expanded criteria, no
qualification may be needed. On the other hanrft if several data
elements are in the expanded windows, all associated data may merit an
estimated flag (J). Please note that the data reviewer is not required to
use expanded criteria. The reviewer may still choose to flag all data
associated with a tune not meeting contract criteria as unusable (R) if
it is deemed appropriate.
III. CALIBRATION
A. Objective
Compliance requirements for satisfactory instrument calibration are established to
ensure that the instrument is capable of producing acceptable quantitative data.
Initial calibration demonstrates that the instrument is capable of acceptable
performance in the beginning, and continuing calibration checks document
satisfactory maintenance and adjustment of the instrument on a day-to-day basis.
B. Criteria
1. Initial Calibration
a. Volatile and Semivolatile Fractions
1) All average Relative Response Factors (RRF) for TCL
compounds must be £ 0.05.
2) All Percent Relative Standard Deviations (%RSD) must be
< 30%.
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2. Continuing Calibration
a. Volatile and Semivolatile Fractions
1) All Relative Response Factors (RRF) for TCL compounds must
be > 0.05.
2) All Percent Difference (%D) must be < 25%.
C. Evaluation Procedure
1. Initial Calibration
a. Evaluate the RRF for all TCL compounds and verify the following:
1) Check and recalculate the RRF and RRF for one or more
volatile and semivolatile TCL compounds; verify that the
recalculated value(s) agrees with the laboratory reported
value(s).
2) Verify that all volatile and semivolatile TCL compounds have
average Relative Response Factors of at least 0.05.
b. Evaluate the Percent Relative Standard Deviation (%RSD) for all TCL
compounds and verify the following:
o ¦ Is
V„ <-,)
% RSD - -2— x 100
x
0 *• Standard deviation of 5 response factors
*x - Mean of 5 response factors
1) Check and recalculate the %RSD for one or more TCL
compounds; verify that the recalculated value agrees with the
laboratory reported value.
2) Verify that all TCL compounds (volatile and semivolatile) have
a %RSD of £ 30%.
If errors are detected in the calculations of either the RRF or the
%RSD, perform a more comprehensive recalculation.
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2. Continuing Calibration
a. Evaluate the RRF for all TCL compounds:
1) Verify that all volatile and semivolatile TCL compounds have
Relative Response Factors of at least 0.0S.
b. Evaluate the Percent Difference and verify the following:
1) Check calculation of % Difference (%D) between initial
calibration average Relative Response Factors and continuing
calibration Relative Response Factors for one or more
compounds, using the following equation:
RRFj - RRFC
%D - —— x 100
RRFj
where,
RRFj * average relative response factor from
initial calibration.
RRF£ - relative response factor from
continuing calibration standard.
2) Verify that the %D is < 25% for all volatile and semivolatile
TCL compounds.
c. If errors are detected in the calculations of either the RRF or the %D,
perform a more comprehensive recalculation.
D. Action
1. Initial Calibration
a. If any volatile or semivolatile TCL compound result has an average
Relative Response Factor of less than 0.05:
1) Flag positive results for that compound as estimated (J).
2) Flag non-detects for that compound as unusable (R).
b. If any volatile or semivolatile TCL compound has a % RSD of greater
than 30%:
1) Flag positive results for that compound as estimated (J).
2) Non-detects may be qualified using professional judgment.
2. Continuing Calibration
a. If any volatile or semivolatile TCL compound has a Relative Response
Factor of less than 0.05:
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1) Flag positive results for that compound as estimated (J).
2) Flag non-detects for that compound as unusable (R).
b. If any volatile or semivolatile TCL compound has a % Difference
between Initial and Continuing Calibration of greater than 25%:
1) Flag all positive results for that compound as estimated (J).
2) Non-detects may be qualified using professional judgment.
IV. BLANKS
A. Objective
The assessment of blank analysis results is to determine the existence and magnitude
of contamination problems. The criteria for evaluation of blanks apply to any blank
associated with the samples. If problems with anv blank exist, all data associated with
the Case must be carefully evaluated to determine whether or not there is an inherent
variability in the data for the Case, or if the problem is an isolated occurrence not
affecting other data.
B. Criteria
No contaminants should be present in the blank(s).
C. Evaluation Procedure
1. Review the results of all associated blank(s), Form I(s) and raw data
(chromatograms, reconstructed ion chromatograms, quantitation reports or data
system printouts).
2. Verify that Method Blank analysis has been reported per matrix, per
concentration level, for each GC/MS system used to analyze VOA samples,
and for each extraction batch for semivolatiles. The reviewer can use the
Method Blank Summary (Form IV) to assist in identifying samples associated
with each Method Blank.
D. Action
Action in the case of unsuitable blank results depends on the circumstances and origin
of the blank. No positive sample results should be reported unless the concentration
of the compound in the sample exceeds 10 times the amount in any blank for the
common contaminants listed below, or 5 times the amount for other compounds. In
instances where more than one blank is associated with a given sample, qualification
should be based upon a comparison with the associated blank having the highest
concentration of a contaminant. The results must ml be corrected by subtracting any
blank value. Specific actions are as follows:
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If a compound is found in a blank but hq£ found in the sample, no action is
taken.
Any compound (other than the five listed below) detected in the sample,
which was also detected in any associated blank, must be qualified when the
sample concentration is less than five times the blank concentration. For the
following five compounds, the results are qualified by elevating the limit of
detection when the sample concentration is less than 10 times the blank
concentration.
Common lab contaminants:
a. Methylene chloride
b. Acetone
c. Toluene
d. 2-butanone
e. Common phthalate esters
The reviewer should note that the blank analyses may not involve the same
weights, volumes, or dilution factors as the associated samples. These factors
must be taken into consideration when applying the Sx and lOx criteria, such
that a comparison of the total amount of contamination is actually made.
Additionally, there may be instances where little or no contamination was
present in the associated blanks, but qualification of the sample was deemed
necessary. Contamination introduced through dilution water is one example.
Although it is not always possible to determine, instances of this occurring can
be detected when contaminants are found in the diluted sample result, but are
absent in the undiluted sample result. Since both results are not routinely
reported, it may be impossible to verify this source of contamination.
However, if the reviewer determines that the contamination is from a source
other than the sample, he/she should qualify the data. In this case, the Sx or
lOx rule does not apply; the sample value should be reported as a non-detect.
The following are examples of applying the blank qualification guidelines.
Certain circumstances may warrant deviations from these guidelines.
Case 1: Sample result is greater than the Contract Required Quantitation
Limit (CRQL), but is less than the required amount (5x or lOx)
from the blank result.
&ik
lOx
Blank Result
CRQL
Sample Result
Qualified Sample Result
7 7
5 5
60 30
60U 30U
In the example for the lOx rule, sample results less than 70 (or 10
x 7) would be qualified as non-detects. In the case of the Sx rule,
sample results less than 35 (or 5 x 7) would be qualified as non-
detects.
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Case 2: Sample result is less than CRQL, and is also less than the required
amount (5x or lOx) from the blank result.
Rule
IQjl
Blank Result 6 6
CRQL 5 5
Sample Result 4J 4J
Qualified Sample Result SU SU
Note that data are not reported as 4U, as this would be reported as
a detection limit below the CRQL.
Case 3: Sample result is greater than the required amount (Sx or lOx) from
the blank result.
Rule
Sa
Blank Result 10 10
CRQL 5 5
Sample Result 120 60
Qualified Sample Result 120 60
For both the lOx and Sx rules, sample results exceeded the
adjusted blank results of 100 (or 10x10) and SO (or SxlO),
respectively.
4. If gross contamination exists (i.e., saturated peaks by GC/MS), all compounds
affected should be flagged as unusable (R), due to interference, in all samples
affected.
5. If inordinate amounts of other TCL compounds are found at low levels in the
blank(s), it may be indicative of a problem at the laboratory and should be
noted in the data review comments which are forwarded to the DPO.
6. Similar consideration should be given to TIC compounds which are found in
both the sample and associated blank(s). (See Section XI for TIC guidance.)
V. SURROGATE RECOVERY
A. Objective
Laboratory performance on individual samples is established by means of spiking
activities. All samples are spiked with surrogate compounds prior to sample
preparation. The evaluation of the results of these surrogate spikes is not necessarily
straightforward. The sample itself may produce effects due to Mich factors as
interferences and high concentrations of analytes. Since the effects of the sample
matrix are frequently outside the control of the laboratory and may present relatively
unique problems, the review and validation of data based on specific sample results is
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frequently subjective and demands analytical experience and professional judgment.
Accordingly, this section consists primarily of guidelines, in some cases with several
optional approaches suggested.
B. Criteria
Sample and blank surrogate recoveries for volatiles and semivolatiles must be within
limits as per applicable SOW (Form II).
C. Evaluation Procedure
1. Check raw data (i.e., chromatograms, quant list, etc.) to verify the recoveries
on the Surrogate Recovery (Form II).
2. The following should be determined from the Surrogate Recovery form(s):
a. If any two surrogates within a base/neutral or acid fraction (or one
surrogate for the VOA fraction) are out of specification, or if any one
base/neutral, acid or VOA surrogate has a recovery of less than 10%,
then there should be a reanalysis with surrogate results still outside the
criteria. (Note: When there are unacceptable surrogate recoveries
followed by successful re-analyses, the labs are required to report only
the successful run.)
b. The lab has failed to perform satisfactorily if surrogate recoveries are
out of specification with no evidence of repurging, reinjection, or re-
extraction.
c. Verify that no blanks have surrogates outside the criteria.
3 Any time there are two or more analyses for a particular fraction the reviewer
must determine which are the best data to report.
Considerations should include:
a. Surrogate recovery (marginal vs. gross deviation).
b. Holding times.
c. Comparison of the values of the TCL compounds reported in each
fraction.
D. Action
For surrogate spike recoveries out of specification, the following approaches are
suggested based on a review of all data from the case, especially considering the
apparent complexity of the sample matrix:
1. If at least two surrogates in a base/neutral or acid fraction or one surrogate in
the volatile fraction are out of specification, but have recoveries greater than
10%:
a. Positive results for that fraction are flagged as estimated (J).
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b. Negative results for that fraction are flagged with the sample
quantitation limit as estimated (UI).
2. If any surrogate in a fraction shows less than 10% recovery.
a. Positive results for that fraction are flagged as estimated (J).
b. Negative results for that fraction are flagged as unusable (R).
3. No qualification with respect to surrogate recovery is placed on data unless at
least two surrogates are out of specification in the base/neutral or acid
fraction, or one in the volatile fraction, or unless any surrogate has a less than
10% recovery.
4 In the special case of a blank analysis with surrogates out of specification, the
reviewer must give special consideration to the validity of associated sample
data. The basic concern is whether the blank problems represent an isolated
problem with the blank alone, or whether there is a fundamental problem with
the analytical process. For example, if one or more samples in the batch show
acceptable surrogate recoveries, the reviewer may choose to consider the blank
problem to be an isolated occurrence. However, even if this judgment allows
some use of the affected data, analytical problems remain that must be
corrected by the laboratory.
VI. MAT1»IY SPIKE/MATRIX SPIKE DUPLICATE
Objective
These data are generated to determine long-term precision and accuracy of the
analytical method on various matrices. These data alone cannot be used to evaluate
the precision and accuracy of individual samples.
Criteria
1. Spike recoveries must be within the advisory limits established in the
appropriate IFB and on Form III.
2. Relative Percent Differences (RPD) between matrix spike and matrix spike
duplicate recoveries must be within the advisory limits established in the
appropriate IFB and on Form III.
Evaluation Procedure
1. Inspect results for the Matrix Spike/Matrix Spike Duplicate Recovery (Form
III).
2. Verify transcriptions from raw data and verify calculations.
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D. Action
No action is taken on Matrix Spike/Matrix Spike Duplicate (MS/MSD) data atone to
qualify an entire Case. However, using informed professional judgment the data
reviewer may use the matrix spike and matrix spike duplicate results in conjunction
with other QC criteria and determine the need for some qualification of the data.
The data reviewer should first try to determine to what extent the results of the
MS/MSD affect the associated data. This determination should be made with regard to
the MS/MSD sample itself as well as specific analytes for all samples associated with
the MS/MSD.
In those instances where it can be determined that the results of the MS/MSD affect
only the sample spiked, then qualification should be limited to this sample alone.
However, it may be determined through the MS/MSD results that a lab is having a
systematic problem in the analysis of one or more analytes, which affects all associated
samples.
Note: If a field blank was used for the MS/MSD, the information must be included on
the ORDA form.
VII. FIELD DUPLICATES
A. Objective
Field duplicate samples may be taken and analyzed as an indication of overall precision.
These analyses measure both field and lab precision; therefore, the results may have
more variability than lab duplicates which measure only lab performance. It is also
expected that soil duplicate results will have a greater variance than water matrices due
to difficulties associated with collecting identical field samples.
B. Criteria
There are no specific review criteria for field duplicate analyses comparability.
C. Evaluation Procedures
Samples which are field duplicates should be identified using EPA Sample Traffic
Reports or sample field sheets. The reviewer should compare the results reported for
each sample and calculate the Relative Percent Difference (RPD).
D. Action
Any evaluation of the field duplicates should be provided with the reviewer's
comments.
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VIII- INTERNAL STANDARDS PERFORMANCE
A. Objective
Internal Standards (IS) performance criteria ensure that GC/MS sensitivity and response
is stable during every run.
B. Criteria
1. Internal standard area counts must not vary by more than a factor of two
(-50% to +100%) from the associated calibration standard.
2. The retention time of the internal standard must not vary more than +30 seconds
from the associated calibration standard.
C. Evaluation Procedure
1. Check raw data (i.e., chromatograms, quantitation lists, etc.) to verify the
recoveries reported on the Internal Standard Area Summary (Form VIIIA, VIIIB).
2. Verify that all retention times and IS areas are acceptable.
3. Any time there are two analyses for a particular fraction, the reviewer must
determine which are the best data to report. Considerations should include:
a. Magnitude of the shift.
b. Holding times.
c. Comparison of the values of the TCL compounds reported in each fraction.
D. Action
1. If an IS area count is outside -50% or +100% of the associated standard:
a. Positive results for compounds quantitated using that IS are flagged as
estimated (J) for that sample fraction.
b. Non-detects for compounds quantitated using that IS are flagged with the
sample quantitation limit classified as estimated (UJ) for that sample
fraction.
c. If extremely low area counts are reported, or if performance exhibits a
major abrupt drop-off, then a severe loss of sensitivity is indicated.
Non-detects should then be flagged as unusable (R).
2. If an IS retention time varies by more than 30 seconds, the chromatographic
profile for that sample must be examined to determine if any false positives or
negatives exist. For shifts of a large magnitude, the reviewer may consider
partial or total rejection of the data for that sample fraction.
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IX. TCT, COMPOUND IDENTIFICATION
Objective
The objective of the criteria for GC/MS qualitative analysis is to minimize the number
of erroneous identifications of compounds. An erroneous identification can either be a
false positive (reporting a compound present when it is not) or a false negative (not
reporting a compound that is present).
The identification criteria can be applied much more easily in detecting false positives
than false negatives. More information is available due to the requirement for
submittal of data supporting positive identifications. Negatives, or non-detected
compounds, on the other hand represent an absence of data and are, therefore, much
more difficult to assess.
Criteria
1. Compound must be within ±0.06 relative retention time (RRT) units of the
standard RRT.
2. Mass spectra of the sample compound and a current laboratory-generated
standard must match according to the following criteria:
a. All ions present in the standard mass spectrum at a relative intensity greater
than 10% must be present in the sample spectrum
b. The relative intensities of ions specified above must agree within +20%
between the standard and sample spectra. (Example: For an ion with an
abundance of 50% in the standard spectrum, the corresponding sample ion
abundance must be between 30% and 70%.)
c. Ions greater than 10% in the sample spectrum but not present in the
standard spectrum must be considered and accounted for.
Evaluation Procedure
1. Check that the RRT of reported compounds is within 0.06 RRT units of the
reference standard.
2. Check the laboratory standard spectra vs. the sample compound spectra.
3. The reviewer should be aware of situations (e.g., high concentration samples
preceding low concentration samples) when sample carry-over is a possibility and
should use judgment to determine if instrument cross-contamination has affected
any positive compound identification.
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D.
Action
1. The application of qualitative criteria for GC/MS analysis of TCL compounds
requires professional judgment. If it is determined that incorrect
identifications were made, all such data should be flagged as not detected (U)
or unusable (R).
2. Professional judgment must be used to qualify the data if it is determined that
cross-contamination has occurred.
X. COMPOUND QUANTITATION AND REPORTED DETECTION LIMITS
A. Objective
The objective is to ensure that the reported quantitation results and CRQLs are
accurate.
B. Criteria
1. Compound quantitation, as well as the adjustment of the CRQL, must be
calculated according to the appropriate SOW.
2. Compound RRF must be calculated based on the IS specified in the SOW for
that compound. Quantitation must be based on the quantitation ion (m/z)
specified in the SOW. The compound quantitation must be based on the RRF
from the appropriate daily standard.
C. Evaluation Procedure
1. For all fractions, raw data should be examined to verify the correct calculation
of all sample results reported by the laboratory. Quantitation lists,
chromatograms, and sample preparation log sheets should be compared to the
reported positive sample results and quantitation limits.
2. Verify that the correct internal standard, quantitation ion, and RRF were used
to quantitate the compound.
3. Verify that the CRQLs have been adjusted to reflect all sample dilutions,
concentrations, splits, clean-up activities, and dry weight factors that are not
accounted for by the method.
D. Action
If there are any discrepancies found, the laboratory may be contacted by the
designated representative to obtain additional information that could resolve any
differences. If a discrepancy remains unresolved, the reviewer must decide which
value is the best value. Under these circumstances, the reviewer may determine
qualification of data is warranted.
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XI. TENTATIVELY IDENTIFIED COMPOUNDS
A. Objective
Chromatographic peaks in volatile and semivolatile fraction analyses that are not
target compound list (TCL) analytes, surrogates, or internal standards are potential
tentatively identified compounds (TIC). TICs must be qualitatively identified by
(GC/MS) library search and the identifications assessed by the data reviewer.
B. Criteria
1. For each sample, the laboratory must conduct a mass spectral search of the
NBS library and report the possible identity for the 10 largest VOA fraction
peaks and the 20 largest BNA fraction peaks which are not surrogate, internal
standard, or TCL compounds, but which have area/height greater than 10
percent of the size of the nearest internal standard. TIC results are reported
for each sample on the Organic Analyses Data Sheet (Form I, TIC).
Note: SOW revision October 1986 does not allow the laboratory to report as
tentatively identified compounds (TICs) any TCL compound which is properly
reported in another fraction. (For example, late eluting volatile TCL
compounds must not be reported as BNA TICs.)
2. Guidelines for tentative identification are as follows:
a. Major ions (greater than 10% relative intensity) in the reference
spectrum should be present in the sample spectrum.
b. The relative intensities of the major ions should agree within ±20%
between the sample and the reference spectra.
c. Molecular ions present in the reference spectrum should be present in
the sample spectrum.
d. Ions present in the sample spectrum but not in the reference spectrum
should be reviewed for possible background contamination,
interference, or coelution of additional TIC or TCL compounds.
e. When the above criteria are not met, but in the technical judgment of
the data reviewer or mass spectral interpretation specialist the
identification is correct, the data reviewer may report the
identification.
f. If in the data reviewer's judgment the identification is uncertain or
there are extenuating factors affecting compound identifications, the
TIC result may be reported as "unknown".
C. Evaluation Procedure
1. Check the raw data to verify that the laboratory has generated a library search
for all required peaks in the chromatograms (samples and blanks).
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2. Blank chromatograms should be examined to verify that TIC peaks present in
samples are not found in blanks. When a low-level non-TCL compound that
is a common artifact or laboratory contaminant is detected in a sample, a
thorough check of blank chromatograms may require looking for peaks which
are less than 10 percent of the internal standard height, but present in the
blank chromatogram at similar relative retention time.
3. All mass spectra in every sample and blank must be examined.
4. Since TIC library searches often yield several candidate compounds having a
close matching score, all reasonable choices must be considered.
5. The reviewer should be aware of common laboratory artifacts/contaminants
and their sources (aldol products, solvent preservatives/reagent contaminants,
etc.). These may be present in blanks and not reported as sample TICs.
Examples:
a. Common lab contaminants: CO? (m/e 44), siloxanes (m/e 73), diethyl
ether, hexane, certain freons (1,1,2-trichloro-1,2,2-trifluoroethane or
fluoro-trichloromethane), phthalates at levels less than 100 ug/1 or
4000 ug/kg.
b. Solvent preservatives: cyclohexene is a methylene chloride preser-
vative. Related by-products include cyclohexanone, cyclohexenone,
cyclohexanol, cyclohexenol, chlorocyclohexene, chlorocyclohexanol.
c. Aldol reaction products of acetone include: 4-hydroxy-4-methyl-2-
pentanone, 4-methyl-2-penten-2-one, 5,5-dimethyI-2(5H)-furanone.
6. Occasionally, a TCL compound may be identified in the proper analytical
fraction by non-target library search procedures, even though it was not found
on the quantitation list. If the total area quantitation method was used, the
reviewer should request that the laboratory recalculate the result using the
proper quantitation ion. In addition, the reviewer should evaluate other
sample chromatograms and check library reference retention times on
quantitation lists to determine whether the false negative result is an isolated
occurrence or whether data from the entire Case may be affected.
7. TCL compounds may be identified in more than one fraction. Verify that
quantitation is made from the proper fraction.
D. Action
1. All TIC results should be flagged as tentatively identified with estimated
concentrations (JN).
2. General actions related to the review of TIC results are as follows:
a. If it is determined that a tentative identification of a non-TCL
compound is not acceptable, the tentative identification should be
changed to "unknown" or an appropriate identification.
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b. If all contractually required peaks were not library searched, the
designated representative could request these data from the laboratory.
3. TIC results which are not sufficiently above the level in the blank should not
be reported. (Dilutions and sample size must be taken into account when
comparing the amounts present in blanks and samples.)
4. When a compound is not found in any blanks, but is a suspected artifact of
common laboratory contaminant, the result may be flagged as unusable (R).
5. In deciding whether a library search result for a TIC represents a realistic
identification, professional judgment must be exercised. If there is more than
one reasonable match, the result may be reported as "either compound X or
compound Y." If there is a lack of isomer specificity, the TIC result may be
changed to a non-specific isomer result (1,3,5-trimethyl benzene to trimethyl
benzene isomer) or to a compound class (2-methyl, 3-ethyl benzene to
substituted aromatic compound).
6. The reviewer may elect to report all similar isomers as a total. (All alkanes
may be summarized and reported as total hydrocarbons.)
7. Other Case factors may influence TIC judgments. If a sample TIC match is
poor but other samples have a TIC with a good library match, similar relative
retention time and the same ions, identification information may be inferred
from the other sample TIC results.
g. Physical constants, such as boiling point, may be factored into professional
judgment of TIC results.
XII. SYSTEM PERFORMANCE
During the period following Instrument Performance QC checks (e.g. blanks, tuning,
calibration), changes may occur in the system that degrade the quality of the data. While this
degradation would not be directly shown by QC checks until the next required series of
analytical QC runs, a thorough review of the ongoing data acquisition can yield indicators of
instrument performance.
Some examples of instrument performance indicators for various factors are as
follows:
1. Abrupt, discrete shifts in reconstructed ion chromatogram (RIC) baseline may
indicate gain or threshold changes.
2. Poor chromatographic performance affects both qualitative and quantitative
results. Indications of substandard performance include:
a. High RIC background levels or shifts in absolute retention times of internal
standards.
b. Excessive baseline rise at elevated temperature.
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c. Extraneous peaks.
d. Loss of resolution as suggested by factors such as non-resolution of 2,4- and
2,5- dinitrotoluene.
e. Peak tailing or peak splitting may result in inaccurate quantitation.
Continued analytical activity with degraded performance suggests lack of attention or
professional experience. Based on the instrument performance indicators, the data reviewer
must decide if the system has degraded to the point of affecting data quality or validity. If
data quality may have been affected, data should be qualified using the reviewer's best
professional judgment.
XIII. OVERALL ASSESSMENT OF DATA FOP A r arf
It is appropriate for the data reviewer to make professional judgments and express
concerns and comments on the validity of the overall data package for a Case This is
particularly appropriate for Cases in which there are several QC criteria out of specification
The additive nature of QC factors out of specification is difficult to assess in an objective
manner, but the reviewer has a responsibility to inform users concerning data quality and
data limitations in order to assist that user in avoiding inappropriate use of the data while
not precluding any consideration of the data at all. The data reviewer would be greatly
assisted in this endeavor if the data quality objectives were provided.
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PESTICIDES PROCEDURE
The requirements to be checked in validation are listed below. ("CCS" indicates that
the contract requirements for these items will also be checked by CCS; CCS requirements are
not always the same as the data review criteria.)
I. Holding Times (CCS - Lab holding times only)
II. Pesticides Instrument Performance (CCS)
III. Calibration
o Initial (CCS)
o Analytical Sequence (CCS)
o Continuing (CCS)
IV. Blanks (CCS)
V. Surrogate Recovery
VI. Matrix Spike/Matrix Spike Duplicate (CCS)
VII. Field Duplicates
VIII. Compound Identification
IX. Compound Quantitation and Reported Detection Limits
X. Overall Assessment of Data for a Case
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I. HOLDING TIMES
A. Objective
The objective is to ascertain the validity of results based on the holding time of the
sample from time of collection to time of analysis or sample preparation, as
appropriate.
B. Criteria
Technical requirements for sample holding times have only been established for water
matrices. The holding times for soils are currently under investigation. When the
results are available they will be incorporated into the data evaluation process. On
October 26, 1984 in Volume 49, Number 209 of the Federal Register, page 43260, the
holding time requirements for pesticides were established under 40 CFR 136 (Clean
Water Act). Samples must be extracted within 7 days and the extract must be
analyzed within 40 days. Both samples and extracts must be stored at 4s C.
C. Evaluation Procedure
Actual holding times are established by comparing sampling date on the EPA Sample
Traffic Report with dates of analysis and extraction on Form I. Examine the sample
records to determine if samples were properly preserved. (If there is no indication of
preservation, it must be assumed that the samples are unpreserved.)
D. Action
If 40 CFR 136 holding times are exceeded, flag all positive results as estimated (J)
and sample quantitation limits as estimated (UJ) and document to the effect that
holding times were exceeded.
1. If holding times are grossly exceeded, either on the first analysis or upon re-
analysis, the reviewer must use professional judgment to determine the
reliability of the data and the effect of additional storage on the sample
results. The reviewer may determine non-detect data are unusable (R).
2. Due to limited information concerning holding times for soil samples, it is left
to the discretion of the data reviewer to apply water holding time criteria to
soil samples.
II. PESTICIDES INSTRUMENT PERFORMANCE
A. Objective
These criteria are established to ensure that adequate chromatographic resolution and
instrument sensitivity are achieved by the chromatographic system. These criteria are
not sample specific; conformance is determined using standard materials. Therefore,
these criteria should be met in all circumstances.
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B. Criteria
1. DDT Retention Time
DDT must have retention time on packed columns (except OV-1 and OV-101)
greater than or equal to 12 minutes.
2. Retention Time Windows
The laboratory must report retention time window data on the Pesticide/PCB
Standards Summary (Form IX) for each GC column used to analyze samples.
3. DDT/Endrin Degradation Check
The total percent breakdown for neither DDT nor endrin may exceed 20%.
The percent breakdown is the amount of decomposition that endrin and 4,4'-
DDT undergo when analyzed by the chromatographic system.
a. For endrin, the percent breakdown is determined by the presence of
endrin aldehyde and/or endrin ketone in the GC chromatogram.
b. For 4,4*-DDT, the percent breakdown is determined from the presence
of 4,4'-DDD and/or 4,4'-DDE in the GC chromatogram.
c. A combined percent breakdown must be calculated if there is evidence
of a peak at the retention time of endrin aldehyde/4,4'-DDD, which
co-elute on the OV-1 packed column (or an equivalent column).
d. Percent breakdown is calculated using the following equations:
% Breakdown Total DDT degradation peak area (DDE + DDD) ^ ^
for 4,4'-DDT Total DDT peak area (DDT + DDE + DDD)
Degradation Peak Areas (endrin aldehyde + endrin ketone) .
% Breakdown _ x 100
for endrin Peak Area (endrin + endrin aldehyde + endrin ketone)
Note 1: Peak area of endrin aldehyde must be measured during
the degradation check to verify system performance.
Endrin aldehyde is not reported on Form 1 because it is
removed by alumina cleanup.
Note 2: The term "peak height" may be substituted for the term
"peak area".
Total degradation peak areas
Combined - (DDE + DDD + endrin aldehyde + endrin ketone)
% Breakdown Total DDT and endrin peak areas
(DDT + DDE + DDD + endrin + endrin aldehyde + endrin ketone)
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4. DBC Retention Time Check
The retention time of DBC in each analysis must be compared to the retention
time of DBC in Evaluation Standard Mix A. The Percent Difference (%D)
must not exceed 2.0% for packed columns, 0.3% for narrow-bore capillary
columns, and 1.5% if wide-bore capillary columns are used.
RT, - RTo
%D - — x 100
where,
RTj ¦ Absolute retention time of dibutylchlorendate in the initial standard
(Evaluation Standard Mix A).
RTS ¦ Absolute retention time of dibutylchlorendate in the subsequent
analyses.
Evaluation Procedure
1. Check raw data to verify that DDT retention time is greater than 12 minutes
on the standard chromatogram and that there is adequate resolution between
peaks.
2. Check raw data to verify that retention time windows are reported on Form
IX, and that all pesticide standards are within the established retention time
windows.
3. Check raw data to verify that the percent breakdown for endrin and 4,4'
-DDT, or the combined percent breakdown, does not exceed 20% in all
Evaluation Standard Mix B analyses on Form VIII D.
4. Check raw data to verify that the percent difference in retention time for
dibutylchlorendate in all standards and samples is < 2.0% for packed column
analysis, < 0.3% for capillary column analysis, and < 1.5% for wide-bore
capillary column analysis on Form VIII E.
Action
1. DDT Retention Time
If the retention time of DDT is less than 12 minutes (except on OV-1 and
OV-101), a close examination of the chromatography is necessary to ensure
that adequate separation of individual components is achieved. If adequate
separation is not achieved, flag all affected compound data as unusable (R).
2. Retention Time Windows
Retention time windows are used in qualitative identification. If the standards
do not fall within the retention time windows, the associated sample results
should be carefully evaluated. All samples injected after the last in-control
standard are potentially affected.
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a. For the affected samples, check to see if chromatograms contain any peaks
within an expanded window surrounding the expected retention time
window of the pesticide of interest. If no peaks are present either within
or close to the retention time window of the deviant target pesticide
compound, there is usually no effect on the data. (Non-detected values can
be considered valid.)
b. If the affected sample chromatograms contain peaks which may be of
concern (i.e., above the CRQL and either close to or within the expected
retention time window of the pesticide of interest), then two options are
available to the reviewer to determine the extent of the effect on the data.
1) If no additional effort is warranted by the reviewer, flag all positive
results and quantitation limits as unusable (R). The narrative should
emphasize the possibility of either false negatives or false positives, as
appropriate.
2) In some cases, additional effort is warranted by the reviewer (e.g., if
the data are needed on a priority basis and if the peak(s) present
might represent a level of concern for that particular pesticide). In
these situations, the reviewer may undertake the following additional
efforts to determine a usable retention time window for affected
samples:
(a) The reviewer should examine the data package for the presence
of three or more standards containing the pesticide of interest
that were run within a 72-hour period during which the sample
was analyzed.
(b) If three or more such standards are present, the mean and
standard deviation of the retention time window can be re-
evaluated.
(c) If all standards and matrix spikes fall within the revised
window, the valid positive or negative sample results can be
determined using this window.
(d) The narrative should identify the additional efforts taken by the
reviewer and the resultant impact on data usability. In
addition, the support documentation should contain all
calculations and comparisons generated by the reviewer.
3. DDT/Endrin Degradation Check
a. If DDT breakdown is greater than 20%, beginning with the samples
following the last in-control standard:
1) Flag all quantitative results for DDT as estimated (J). If DDT was
not detected, but DDD and DDE are positive, then flag the
quantitation limit for DDT as unusable (R).
2) Flag results for DDD and/or DDE as presumptively present at an
estimated quantity (NJ).
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b. If endrin breakdown is greater than 20%:
1) Flag all quantitative results for endrin as estimated (J). If endrin was
not detected, but endrin aldehyde and endrin ketone are positive,
then flag the quantitation limit for endrin as unusable (R).
2) Flag results for endrin ketone as presumptively present at an
estimated quantity (NJ).
4. Retention Time Check
a. If the retention time shift for dibutylchlorendate (DBC) is greater than 2.0%
for packed column, greater than 0.3% for narrow-bore capillary column, or
greater than 1.5% for wide-bore capillary column, the analysis may be
flagged unusable for that sample(s) (R), but qualification of the data is left
up to the professional judgment of the reviewer.
b. The retention time shift cannot be evaluated in the absence of DBC.
III. CALIBRATION
A. Objective
Compliance requirements for satisfactory instrument calibration are established to
ensure that the instrument is capable of producing acceptable quantitative data. Initial
calibration demonstrates that the instrument is capable of acceptable performance in the
beginning, and continuing calibration checks document satisfactory maintenance and
adjustment of the instrument over specific time periods.
B. Criteria
1. Initial Calibration Linearity Check
The Percent Relative Standard Deviation (%RSD) of calibration factors for
aldrin, endrin, DDT, and dibutylchlorendate must not exceed 10%. If
toxaphene is identified and quantified, a three-point calibration is required.
If the calibration factor for DDT or toxaphene is outside the 10% RSD
window, calibration curves must be used for quantitation of DDT, DDE,
DDD, or toxaphene.
Calibration Factor = Total Area pf Peak
Mass Injected (ng)
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%RSD = x 100
CF
where,
-------
c. Verify that the %RSD for the calibration factor of each specific
pesticide is Jess than or equal to 10% for each 72-hour period.
d. If errors are detected, more comprehensive recalculation should be
performed.
e. If toxaphene or the DDT series was identified and quantitated, verify
that a three-point calibration was established.
2, Verify that all standards were analyzed in the 72-hour sequence.
3. Continuing Calibration
a. Review the pesticide sample data to verify whether the standard was
used as a quantitation standard or as a confirmation standard.
b. For the quantitation standards, check the raw data to verify the percent
difference (%D), using the following formula, for approximately ten
percent of the reported values by recalculation.
R| ~ R->
%D = L X 100
R1
where,
Rj - Calibration Factor from first analysis
R2 = Calibration Factor from subsequent analysis
D. Action
1. Initial Calibration
If criteria for linearity are not met, flag all associated quantitative results as
estimated (J).
2. Analytical Sequence
If the proper standards have not been analyzed, data may be affected. The
data reviewer must use professional judgment to determine severity of the
effect and qualify the data accordingly.
3. Continuing Calibration
a. If the %D between calibration factors is greater than 15% for the
compound(s) being quantitated (20% for compounds being confirmed),
flag all associated positive quantitative results as estimated (J).
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IV. BLANKS
Objective
The assessment of blank analysis results is to determine the existence and magnitude
of contamination problems. The criteria for evaluation of blanks apply to any blank
associated with the samples. If problems with any blank exist, all data associated with
the Case must be carefully evaluated to determine whether or not there is an inherent
variability in the data for the Case, or the problem is an isolated occurrence not
affecting other data.
Criteria
No contaminants should be present in the blank(s).
Evaluation Procedure
Review the results of all associated blank(s), Form I(s) and raw data
(chromatograms. Quantitation reports or data system printouts).
Verify that the method blank analysis(es) contains less than the Contract
Required Quantitation Limits (CRQL) of any Pesticide/PCB or interfering
peak.
Verify that method blank analysis has been reported per matrix, per
concentration level, for each GC system used to analyze samples, and for each
extraction batch.
Action
Action in the case of unsuitable blank results depends on the circumstances and the
origin of the blank. No positive sample results should be reported unless the
concentration of the compound in the sample exceeds 5 times the amount in the
blank. In instances where more than one blank is associated with a given sample,
qualification should be based upon a comparison with the associated blank having the
highest concentration of a contaminant. The results must not be corrected by
subtracting the blank value. Specific actions are as follows:
1. If a Pesticide/PCB is found in the blank but sot found in the sample(s), no
action is taken.
2. Any Pesticide/PCB detected in the sample and also detected in any associated
blank, must be qualified when the sample concentration is less than S times
the blank concentration.
The reviewer should note that the blank analyses may not involve the same
weights, volumes or dilution factors as the associated samples. These factors
must be taken into consideration when applying the Sx criteria, such that a
comparison of the total amount of contamination is actually made.
Additionally, there may be instances where little or no contamination was
present in the associated blanks, but qualification of the sample was deemed
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necessary. Contamination introduced through dilution water is one example.
Although it is not always possible to determine, instances of this occurring can
be detected when contaminants are found in the diluted sample result, but
absent in the undiluted sample result. Since both results are not routinely
reported, it may be impossible to verify this source of contamination.
However, if the reviewer determines that the contamination is from a source
other than the sample, he/she should qualify the data. In this case, the 5x rule
does not apply; the sample value should be reported as a non-detect.
3. The following are examples of applying the blank qualification guidelines.
Certain circumstances may warrant deviations from these guidelines.
Case 1: Sample result is greater than the CRQL, but is less than the
required amount (Sx) from the blank result.
Blank Result 1.0
CRQL .5
Sample Result 4.0
Qualified Sample Result 4.0U
In this case, sample results less than 5.0 (or 5 x 1.0) would be
qualified as non-detects.
Case 2: Sample result is greater than the required amount (Sx) from the
blank result.
&
Blank Result 1.0
CRQL .5
Sample Result 6.0
Qualified Sample Result 6.0
V. SURROGATE RECOVERY
A. Objective
Laboratory performance on individual samples is established by means of spiking
activities. All samples are spiked with a surrogate compound prior to sample
preparation. The evaluation of the results of these surrogate spikes is not necessarily
straightforward. The sample itself may produce effects due to such factors as
interferences and high concentrations of analytes. Since the effects of the sample
matrix are frequently outside the control of the laboratory and may present relatively
unique problems, the review and validation of data based on specific sample results is
frequently subjective and demands analytical experience and professional judgment.
Accordingly, this section consists primarily of guidelines, in some cases with several
optional approaches suggested.
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B. Criteria
Sample and blank recoveries of dibutylchlorendate must be within limits as per
applicable SOW (Form II).
C. Evaluation Procedure
1. Check raw data (i.e., chromatograms, quant list, etc.) to verify the recoveries
on the Surrogate Recovery (Form II).
2. If recoveries are not within limits, check raw data for possible interferences
which may have affected surrogate recoveries.
D. Action
If pesticide surrogate recoveries are outside of advisory windows, the following
guidance is suggested:
1. If low recoveries are obtained, flag associated positive results and quantitation
limits as estimated (J).
2. If high recoveries are obtained, professional judgment should be used to
determine appropriate action. A high bias may be due to co-eluting
interferences.
3. If zero pesticide surrogate recovery is reported, the reviewer should examine
the sample chromatogram to determine if the surrogate may be present, but
slightly outside its retention time window. If this is the case, in addition to
assessing surrogate recovery for quantitative bias, the overriding consideration
is to investigate the qualitative validity of the analysis. If the surrogate is not
present, flag all negative results as unusable (R).
VI. MATRIX SPIKE/MATRIX SPIKE DUPLICATE
A. Objective
These data are generated to determine long-term precision and accuracy of the
analytical method on various matrices. These data alone cannot be used to evaluate
the precision and accuracy of individual samples.
B. Criteria
1. Advisory limits are established for spike recovery limits in the appropriate
SOW and on Form III.
2. Advisory limits are established for relative percent difference between matrix
spike and matrix spike duplicate recoveries in the appropriate SOW and on
Form III.
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C. Evaluation Procedure
1. Inspect results for the Matrix Spike/Matrix Spike Duplicate Recovery (Form
III).
2. Verify transcriptions from raw data and verify calculations.
D. Action
No action is taken on Matrix Spike/Matrix Spike Duplicate (MS/MSD) data alone to
qualify an entire Case. However, using informed professional judgment, the data
reviewer may use the matrix spike and matrix spike duplicate results in conjunction
with other QC criteria and determine the need for some qualification of the data.
The data reviewer should first try to determine to what extent the results of the
MS/MSD affect the associated data. This determination should be made with regard
to the MS/MSD sample itself as well as specific analytes for all samples associated
with the MS/MSD.
In those instances where it can be determined that the results of the MS/MSD affect
only the sample spiked, then qualification should be limited to this sample alone.
However, it may be determined through the MS/MSD results that a lab is having a
systematic problem in the analysis of one or more analytes, which affects all
associated samples.
VII. FIELD DUPLICATES
A. Objective
Field duplicate samples may be taken and analyzed as an indication of overall
precision. These analyses measure both field and lab precision; therefore, the results
may have more variability than lab duplicates which measure only lab performance.
It is also expected that soil duplicate results will have a greater variance than water
matrices due to difficulties associated with collecting identical field samples.
B. Criteria
There are no specific review criteria for field duplicate analyses comparability.
C. Evaluation Procedures
Samples which are field duplicates should be identified using EPA Sample Traffic
Reports or sample field sheets. The reviewer should compare the results reported for
each sample and calculate the Relative Percent Difference (RPD).
D. Action
Any evaluation of the field duplicates should be provided with the reviewer's
comments.
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VIII. COMPOUND IDENTIFICATION
A. Objective
Qualitative criteria for compound identification have been established to minimize the
number of erroneous identifications of compounds. An erroneous identification can
either be a false positive (reporting a compound present when it is not) or a false
negative (not reporting a compound that is present).
B. Criteria
1. Retention times of reported compounds must fall within the calculated
retention time windows for the two chromatographic columns.
2. GC/MS confirmation is required if the concentration of a compound exceeds
10 ng/uL in the final sample extract.
C. Evaluation Procedure
1. Review Form I, the associated raw data (chromatograms and data system
printouts) and the Pesticide/PCB Identification Summary (Form X). Confirm
reported positive detects, using appropriate retention times and retention time
windows, and verify that the compounds listed as "not detected" are correct.
2. Verify that positive identifications have dissimilar column analysis. (The 3%
OV-1 column cannot be used for confirmation if both dieldrin and DDE are
identified.)
3. For multipeak pesticides (chlordane and toxaphene) and PCBs, the retention
times and relative peak height ratios of major component peaks should be
compared against the appropriate standard chromatograms.
4. Verify that GC/MS confirmation was performed for pesticides/PCB
concentrations in the final sample extract which exceeded 10 ng/uL.
D. Action
1. If the qualitative criteria for two-column confirmation were not met, all
reported positive detects should be considered non-detects. The reviewer
should use professional judgment to assign an appropriate quantitation limit
using the following guidance:
a. If the misidentified peak was sufficiently outside the target pesticide
retention time window, then the CRQL can be reported.
b. If the misidentified peak poses an interference with potential detection
of a target peak, then the reported value should be considered and
flagged as the estimated quantitation limit (UJ).
2. If PCBs or multipeak pesticides exhibit marginal pattern-matching quality,
professional judgment should be used to establish whether the differences are
attributable to environmental "weathering". If the presence of a
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PCB/multipeak pesticide is strongly suggested, results should be reported as
presumptively present (N).
If an observed pattern closely matches more than one Aroclor, professional
judgment should be used to decide whether the neighboring Aroclor is a better
match, or if multiple Aroclors are present.
3. If GC/MS confirmation was required but not performed, the reviewer should
notify the DPO.
IX. COMPOUND QUANTITATION AND REPORTED DETECTION LIMITS
Objective
The objective is to ensure that the reported quantitation results and CRQLs are
accurate.
Criteria
Compound quantitation, as well as the adjustment of the CRQL, must be calculated
according to the appropriate SOW.
Evaluation Procedure
1. Raw data should be examined to verify the correct calculation of all sample
results reported by the laboratory. Quantitation reports, chromatograms, and
sample preparation log sheets should be compared to the reported positive
sample results and quantitation limits.
2. Verify that the CRQLs have been adjusted to reflect all sample dilutions,
concentrations, splits, clean-up activities, and dry weight factors that are not
accounted for by the method.
Action
Quantitation limits affected by large, off-scale peaks should be flagged as unusable
(R). If the interference is on-scale, the reviewer can provide an estimated
quantitation limit (UJ) for each affected compound.
Note: Simple-peak pesticide results can be checked for rough agreement between
quantitative results obtained on the two GC columns. The reviewer should use
professional judgment to decide whether a much larger concentration obtained on one
column versus the other indicates the presence of an interfering compound. If an
interfering compound is indicated, the lower of the two values should be reported and
qualified as presumptively present at an estimated quantity (NJ). This necessitates a
determination of an estimated concentration on the confirmation column. The
narrative should indicate that the presence of interferences has obscured the attempt
at a second column confirmation.
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x. OVERALL ASSESSMENT OF l>ATA FOR A TASK
It is appropriate for the data reviewer to make professional judgments and express
concerns and comments on the validity of the overall data package for a Case. This is
particularly appropriate for Cases in which there are several QC criteria out of specification.
The additive nature of QC factors out of specification is difficult to assess in an objective
manner, but the reviewer has a responsibility to inform users concerning data quality and
data limitations in order to assist that user in avoiding inappropriate use of the data, while
not precluding any consideration of the data at all. The data reviewer would be greatly
assisted in this endeavor if the data quality objectives were provided.
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GLOSSARY A
Data Qualifier Definitions
For the purposes of this document the following code letters and associated definitions are
provided.
U - The material was analyzed for, but was not detected. The associated
numerical value is the sample quantitation limit.
J - The associated numerical value is an estimated quantity.
R - The data are unusable (compound may or may not be present). Resampling
and reanalysis is necessary for verification.
N - Presumptive evidence of presence of material.
NJ - Presumptive evidence of the presence of the material at an estimated
quantity.
UJ - The material was analyzed for, but was not detected. The sample
quantitation limit is an estimated quantity.
The reviewer may determine that qualifiers other than those used in this document are
necessary to describe or qualify the data. In these instances, it is the responsibility of each
Region to thoroughly document/explain the qualifiers used.
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GLOSSARY B
Other Terms
BFB Bromofluorobenzene — volatile tuning compound
BNA Base/Neutral/Acid Compounds — compounds analyzed by semivolatile technique
Case A finite, usually predetermined number of samples collected over a given time
period for a particular site. A case consists of one or more Sample Delivery
Group(s).
CCC Calibration Check Compound
CCS Contract Compliance Screening - process in which SMO inspects analytical data
for contractual compliance and provides results to the Regions, laboratories and
EMSL/LV.
CF Calibration Factor
CRQL Contract Required Quantitation Limit
DFTPP Decafluorotriphenylphosphine — semivolatile tuning compound
DPO Deputy Project Officer
EICP Extracted Ion Current Profile
GC/EC Gas Chromatography/Electron Capture Detector
GC/MS Gas Chromatograph/Mass Spectrometer
GPC Gel Permeation Chromatography - A sample clean-up technique that separates
compounds by size and molecular weight. Generally used to remove oily
materials from sample extracts.
IS Internal Standards - Compounds added to every VOA and BNA standard, blank,
matrix spike duplicate, and sample extract at a known concentration, prior to
instrumental analysis. Internal standards are used as the basis for quantitation
of the target compounds.
MS/MSD Matrix Spike/Matrix Spike Duplicate
m/z The ratio of mass (m) to charge (z) of ions measured by GC/MS
OADS Organic Analysis Data Sheet (Form I)
ORDA Organic Regional Data Assessment
PCB Polychlorinated biphenyl
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PE Sample Performance Evaluation Sample
Primary One of two types of pesticide/PCB analysis by GC/EC techniques, the other
Analysis being confirmation analysis. If the two analyses are run at separate times, the
primary analysis is the first analysis chronologically, and is used to establish the
tentative identification of any pesticides/PCBs detected. The identification is
then confirmed in the confirmation analysis. If the two analyses are done
simultaneously, either may be considered the primary analysis. Either may be
used for quantitation if contract criteria are met.
QA Quality Assurance - Total program for assuring the reliability of data.
QC Quality Control - Routine application of procedures for controlling the
monitoring process.
RIC Reconstructed Ion Chromatogram
RPD Relative Percent Difference (between matrix spike and matrix spike duplicate)
RRF Relative Response Factor
RRF Average Relative Response Factor
RRT Relative Retention Time (with relation to internal standard)
RSD Relative Standard Deviation
RT Retention Time
SDG Sample Delivery Group - Defined by one of the following, whichever occurs
first;
o Case of field samples
o Each 20 field samples within a Case
o Each 14-day calendar period during which field samples in a Case are
received, beginning with receipt of the first sample in the SDG. (For VOA
contracts, the calendar period is 7-day.)
SMO Sample Management Office
SOP Standard Operating Procedure
SOW Statement of Work
SPCC System Performance Check Compound
SV Semivolatile analysis - Method based on analysis by GC/MS for BNA organic
compounds.
TCL Target Compound List
TIC Tentatively Identified Compound - A compound not on the TCL.
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Volatile Organic Analysis - Method based on the purge and trap technique for
organic compound analysis.
Validated Time of Sample Receipt — Time of sample receipt at the laboratory as
recorded on the shipper's delivery receipt and Sample Traffic Report.
Standard Deviation Estimate (of a sample)
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Region
ORGANIC REGIONAL DATA ASSESSMENT
CASE NO SITE
LABORATORY NO. OF SAMPLES/
MATRIX
SDG # REVIEWER (IF NOT ESD)
SOW# REVIEWER'S NAME
DPO: ACTION FYI COMPLETION DATE
DATA ASSESSMENT SUMMARY
VOA BNA PEST OTHER
1. HOLDING TIMES
2. GC/MS TUNE/INSTR. PERFORM.
3. CALIBRATIONS
4. BLANKS
5. SURROGATES
6. MATRIX SPIKE/DUP
7. OTHER QC
8. INTERNAL STANDARDS
9. COMPOUND IDENTIFICATION
10. SYSTEM PERFORMANCE
11. OVERALL ASSESSMENT
O - Data had no problems/or qualified due to minor problems.
M » Data qualified due to major problems.
Z - Data unacceptable.
X - Problems, but do not affect data.
ACTION ITEMS:
AREAS OF CONCERN:
NOTABLE PERFORMANCE:
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