ENVIRONMENTAL PROTECTION AGENCY
             OFFICE OF ENFORCEMENT
                   WORKSHOP ON
                  PREPARATION TECHNIQUES
             ORGANIC POLLUTANT ANALYSIS
                 OCTOBER 2-4, 1973
                 DENVER, COLORADO
                 DISTRIBUTED BY
NATIONAL FIELD INVESTIGATIONS CENTER-DENVER
               DENVER.COLORADO
                NOVEMBER 1973

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                                95OR730O9
   Environmental Protection Agency
            Workshop on
  Sample Preparation Techniques for
     Organic Pollutant Analysis
          October 2-4, 1973

          Denver, Colorado



             Chairman

 Dr.  Theodore 0. Meiggs, NFIC-Denver



         Discussion Leaders

  Mr. James J. Lichtenberg, MDQARL

  Mr. Roger C. Tindle, NFIC-Denver

      Dr.  Ronald G. Webb, SEWL
          Distributed by

        Office of Enforcement
National Field Investigations Center
         Denver, Colorado
          November, 1973

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                          TABLE OF CONTENTS







                                                                  Page




PARTICIPANTS	     ii
INTRODUCTION
  I.  SAMPLE COLLECTION AND PRESERVATION TECHNIQUES    	      3






 II.  EXTRACTION PROCEDURES 	     10






III.  FRACTIONATION AND DERIVATIZATION PROCEDURES  	     20






 IV.  QUALITY CONTROL IN THE ORGANIC LABORATORY 	     25







  V.  GENERAL COMMENTS  	     30

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                             Workshop on
                  Sample Preparation Techniques for
                     Organic Pollutant Analysis
                            PARTICIPANTS
Dr. Clark Allen
Enforcement & Support Branch
Region VI
1600 Patterson Street
Suite 1100
Dallas, Texas  75201

Dr. William Andrade
S & A Division
Region I
Needham Heights, Mass.  02194

Mr. James Barren
Charlottesville Laboratory
Region III
1140 River Road
Charlottesville, Virginia  22901

Mr. H. Gregory Beierl
Pesticide Laboratory
S & A Division
Region VIII
Building 45
Denver Federal Center
Denver, Colorado  80225

Mr. Thomas Bellar
Methods Development & Quality
  Assurance Research Laboratory
NERC-Cincinnati
Cincinnati, Ohio  45268

Dr. Frank J. Biros
Pesticide Effects Laboratory
NERC - RTF
Research Triangle Park, N.C. 27711

Dr. Joseph Blazevich
S & A Division
Region X
14515 SE 21st Place
Bellvue, Washington  98007

Mr. Harvey W. Boyle
National Field Investigations Center
Building 53, Box 25227
Denver Federal Center
Denver, Colorado  80225
                                 ii
Mr. Mike Carter
Southeast Water Laboratory
College Station Road
Athens, Georgia  30601

Mr. Richard Dobbs
Water Supply Research Laboratory
NERC - Cincinnati
4676 Columbia Parkway
Cincinnati, Ohio  45226

Mr. James W. Eichelberger
Analytical Quality Control Laboratory
1014 Broadway
Cincinnati, Ohio  45202

Dr. Richard Enrione
National Field Investigations Center
5555 Ridge Avenue
Cincinnati, Ohio  45268

Mr. Mike E. Garza, Jr.
Houston Facility
S & A Division
Region VI
6608 Hornwood
Houston, Texas  77036

Dr. Gary Glass
National Water Research Laboratory
6201 Congdon Boulevard
Duluth, Minnesota  55804

Dr. Donald F. Goerlitz
U. S. Geological Survey
Water Resources Division
345 Middlefield Road
Menlo Park, California  94025

Mr. William L. Griffis
Consolidated Laboratory Services
NERC - Corvallis
200 SW 35th Street
Corvallis, Oregon  97330

Mr. Michael Gruenfeld
Edison Water Quality Research
  Laboratory
Edison, New Jersey  08817

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                        PARTICIPANTS (Cont.)
Dr. Larry Harris
Analytical Quality Control
  Laboratory
1014 Broadway
Cincinnati, Ohio  45202

Mr. Lloyd Kahn
S & A Division
Region II
Edison, New Jersey  08817

Dr. Robert Kleopfer
S & A Division
Region VII
25 Funston Road
Kansas City, Kansas 66115

Mr. Fred Kopfler
Water Supply Research Laboratory
NERC - Cincinnati
4676 Columbia Parkway
Cincinnati, Ohio  45268

Mr. Thomas Leiker
National Field Investigations Center
Building 53, Box 25227
Denver Federal Center
Denver, Colorado  80225

Mr. James Lichtenberg
Method Development and Quality
  Assurance Research Laboratory
NERC-Cincinnati
Cincinnati, Ohio  45268

James E. Longbottom
Method Development and Quality
  Assurance Research Laboratory
NERC-Cincinnati
Cincinnati, Ohio  45268

Mr. William Loy
Laboratory Services Branch
S & A Division
Region IV
Southeast Water Laboratory
College Station Road
Athens, Georgia  30601

Dr. Theodore 0. Meiggs
National Field Investigations Center
Building 53, Box 25227
Denver Federal Center
Denver, Colorado  80225
Mr. Jerry Muth
Laboratory Support Branch
S & A Division
Region IX
620 Central Avenue
Alameda, California  94501

Mr. William L. Reichel
Bureau of Sport Fisheries & Wildlife
Patuxent Wildlife Research Center
Chemistry - Pathology Building
Laurel, Maryland  20810

Dr. Peter Rogerson
National Marine Water Quality
  Laboratory
South Ferry Road
Narragansett, Rhode Island  02822

Dr. Craig Shew
Robert S. Kerr Water Research Center
P. 0. Box 1198
Ada, Oklahoma  74820

Dr. David L. Stalling
Bureau of Sport Fisheries & Wildlife
Fish-Pesticide Research Laboratory
RD /'I
Columbia, Missouri  65201

Dr. Emilio Sturino
S & A Division
Region V
1819 West Pershing Road
Chicago, Illinois 60609

Mr. John Tilstra
S & A Division
Region VIII
Box 25345
Denver Federal Center
Denver, Colorado  80225

Mr. Roger C. Tindle
National Field Investigations Center
Building 53, Box 25227
Denver Federal Center
Denver, Colorado  80225
                                iii

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                        PARTICIPANTS (Cont.)
Dr. Oilman Veith
National Water Quality Laboratory
6201 Congdon Boulevard
Duluth, Minnesota  55804

Mr. Larry Wapensky
S & A Division
Region VIII
490 Orchard Street
Golden, Colorado  80401

Mr. Virgil L. Warren
National Field Investigations Center
Building 53, Box 25227
Denver Federal Center
Denver, Colorado  80225

Dr. James Watson
National Field Investigations Center
Building 53, Box 25227
Denver Federal Center
Denver, Colorado  80225

Dr. Ronald G. Webb
Southeast Water Laboratory
College Station Road
Athens, Georgia  30601

Mr. Robert E. White
Bureau of Sport Fisheries & Wildlife
Wildlife Research Center
Building 16
Denver Federal Center
Denver, Colorado  80225

Dr. A. J. Wilson
Gulf Breeze Laboratory
Sabine Island
Gulf Breeze, Florida  32561
                                  IV

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                            INTRODUCTION






     Throughout our Country, large quantities of industrial organic




chemicals are being discharged daily to our rivers and lakes.  Histor-




ically, the primary concern for these pollutants has been the oxygen




demand they exert upon the receiving waters.  However, it has become




increasingly apparent that many of these organic chemicals can produce




other adverse affects.  Many of these compounds are highly toxic to




aquatic life, some are carcinogenic, mutagenic, or teratogenic, while




others undergo bio-concentration within the food chain.  As a result,




the discharge of these materials into the aqueous environment can pose




a grave threat to the receiving water biota and in some cases even to




the ultimate consumer - man.




     Before much progress can be made to reduce this form of pollution




analytical techniques must be developed to identify and quantitate




individual chemical pollutants.  However, the complex mixtures of




organic compounds, and the low concentrations that are normally encoun-




tered, have made the analytical task formidable.  Recent advance in




analytical techniques and instrumentation have allowed some progress




to be made in this difficult task.  Consequently, a number of water




laboratories have begun to apply these new techniques to the analysis




of industrial-waste discharges and the receiving-water systems.




     The purpose and goal of this workshop was to bring together the




chemists who are responsible for organic-pollutant analysis, and to




serve as a forum to exchange the varied experiences and accomplishments




that have occurred in this rapidly developing field.  The emphasis of

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the workshop was placed upon the problems of samnle collection,




extraction, and fractionation prior to detettion of the pollutants




of interest by the appropriate detection techniques.  Wherever pos-




sible, methods or procedures were stressed that were applicable to the




analysis for general classes of organic compounds as opposed to pro-




cedures for individual compound identifications.




     What follows is a summation of the techniques discussed at the




workshop.  Many of these are currently being used by water laboratories




to analyze industrial effluents, natural waters, bottom sediments, and




aquatic biota for industrial and agricultural organic-chemical pollu-




tants.  In addition, some discussion is provided regarding analytical




quality control in the organic laboratory as well as a summation of




miscellaneous, general comments that were expressed at the meeting.




     It is felt that the summary of this workshop will serve as a




guide to current practices in the analysis for organic-chemical pol-




lutants , and draw attention to those areas where more information




is needed.

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               I.  SAMPLE COLLECTION AND PRESERVATION







     Sample collection and preservation is an area where considerable




research and development is needed.  There was general agreement among




the workshop particioants that there are, at present, no definitive




guides to sample collection and preservation for organic-pollutant




analysis.  In addition, less than ten percent of the laboratories repre-




sented indicated that they routinely participate in the actual collection




of samples for organic analysis.   This would Indicate that very few




chemists have direct input into the planning and conducting of sampling




programs.  In this respect, there was unanimous agreement that the analyst




should participate in the design of the sample collection process, par-




ticularly with respect to the preparation of sample containers, check on




purity of solvents and reagents,  etc.  Also, there was agreement that the




chemists should be allowed to train sampling crews to avoid potential




sources of sample contamination.




     In light of the expressed attitudes, it seems reasonable that some




group within EPA should be assigned the task of preparing a sampling




manual for use in training and guiding sampling crews who are to collect




samples for organic analysis.




     By far, the largest number of samples analyzed by the various




laboratories are grab-water samples.  Despite this fact, there seemed




to be little real knowledge of the effects of collection method, con-




tainer materials, handling procedures, etc. on the quality of the




resulting sample.  However, it should be emphasized that discussions




did not include the relatively well-developed area of pesticide residue

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analysis since the planners of the workshop felt that pesticide residue




methodology is probably not sufficiently applicable to the problem of




sampling for the wide variety of industrial organic compounds that may




be encountered.




     There was considerable discussion on the choice of sample container




to be used in grab sampling.  Most attendees agreed that glass bottles




or jars were preferred, but one chemist suggested the possibility of




sample contamination due to leaching of materials from soft glass.  The




mechanism of contamination from this source is not known, but the use




of borosilicate glass (Pyrex, Kimax, etc.) seems to avoid the problem.




This phenomenon needs to be studied further.




     Most attendees felt that teflon-cap liners should be used to avoid




sample contamination and losses, but a limited amount of evidence sug-




gests that some solutes, notably PCBs, may be lost to, or through teflon




liners.  In these cases, aluminum-foil liners proved superior.  Again,




research is needed in this area.     )




     Some attendees pointed out that serious losses of solutes from




water samples may occur due to volatilization from the water surface.




This effect has been particularly noticed with petroleum samples.  A




recent paper by Mackay and Wolkoff [Env.  Sai. Technol. , 7, fill (1973)]




attempted to mathematically define the losses that occur due to vapori-




zation of various compounds, including Aroclor 1260.  The authors made.




some assumptions regarding vapor densities, etc., and produced some




rather interesting conclusions.  For example, if we assume that the




sanple bottle commonly used by EPA laboratories contains 850 ml of




liquid and 50 ml of air space, then at 4C about 20 percent of the

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Aroclor 1260 from an Initially saturated solution will be found in




the air space.  Also, since this is the equilibrium situation, shaking




the sample should not redissolve the vaporized material.  At higher




temperatures, these losses would be even greater due to the greater




evaporation of water into the air space.  While some of the assump-




tions used for this estimate are probably not entirely true, the order




of magnitude is probably correct.  Thus, vaporization from a water




sample into the air space in a partially filled jar may represent a




"iajor source of error in the analysis of grab samples for PCBs, aro-




matics, alkanes, and other organic materials.  Obviously, the smaller




the air space above the sample, the smaller the losses that may occur




due to vaporization.  However, as pointed out by some of the Workshop




participants, if there is sufficient petroleum, or other organic material,




to form a microscopic layer over the surface of the water, then losses




due to capillarity (creeping of the organics out of the minute space




between the jar lip and the cap liner) may become significant when the




jar is nearly full.  Again, we have a problem that deserves consid-




erable attention.




     Contamination of grab samples was a major concern of most Workshop




participants.  Contamination can occur in many ways; one of the most




common results from inadequate pre-cleaning of sample containers.  To




minimize this, the chemists 'Should provide properly prepared (pre-




washed) containers to the sampling crews.

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     Other sources of contamination are the caps used to seal sample




bottles (metal caps.must be freed of lacquer prior to use, while




plastic caps may contain plasticizers), sealing tape used to assure




that the caps remain tightly closed, glassware or other sampling gear




used to prepare the sample for transfer to the sample bottle, reagents




and solvents used for preservation, and possible other sources.  The




best answers to the contamination problem seem to be careful pre-




paration of the sample containers before use, training of field crews




so that they will avoid possible contamination sources, and careful




pre-screening (and if necessary, pre-cleaning) of reagents and solvents




for field use.  Among the most common contaminants are phthalate esters,




but many other types of compounds may be encountered.




     Integrated sampling comprises the various techniques whereby




samples are taken over an extended period of time, and in which the rate




of sampling is related in some manner to time or the rate of flow of the




sampled body.  The commonly practiced technique of manually compositing




grab samples over a period of time is an example of this type of sampling.




Compositing was not discussed to any extent during the workshop, however,




as usually practiced, solute losses due to vaporization probably repre-




sent a major problem when this method is used.




     The Workshop participants showed considerable interest in the use of




macroreticular resins for integrated sampling.  Four of the represented




laboratories, including three from EPA, had previously worked with




macroreticular resin columns.  Those that had used resins agreed that




this approach to sampling seems to hold a great deal of promise.

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     In a recent example [R. Tindle, AQC Newlettsr, #19, October, 1973],




a mixed bed of Amberlite XAD-2 and XAD-7 (50:50 mixture) had been used




in a sampling column, which also contained polyurethane-foam plugs both




before and after the resin bed, to sample for several pesticide and




industrial-organic compounds ranging from hydrocarbons to phenols.




This system exhibited good, trapping efficiencies (>90 percent) for most




tested compounds, and upon elution gave overall recoveries generally




of >90 percent.




     Some Workshop attendees pointed out that recoveries may be flow-




rate dependent and some gel-filtration effects (exclusion of large




molecules) may be noted.




     The greatest potential for resin-column use seems to lie in the area




of long-term (24-96 hours) sampling for low levels of organics in lakes,




streams, etc.  Much work needs to be done to define the usefulness and




limitations of this method.  However, the potential usefulness certainly




justifies a concerted initial evaluation.




     Some of the characteristics of the resin-column samplers that need




to be defined are:




     (a)  quantitative aspects - "What compounds are quantitatively




          trapped and over what concentration range?"




     (b)  preparation of resins - "How can resins best be prepared




          for use?"




     (c)  column capacity - "What is the capacity of a particular




          size of column?  Are there interactions between solutes?"




     (d)  preservation of columns - "How can columns be preserved




          before extraction?"

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                                                                  8






      (e)  particulates on columns - "How should partlculates be




          handled?  What are the effects of partial plugging?"




      (f)  elution procedures - "What is best method of eluting




          columns?  Are separation based on pH or solubility




          feasible?"




     There was some discussion of carbon adsorption.  Very few, if




any, of the represented laboratories now use this method, although




three Regional Offices appear to be considering use of this method




for monitoring purposes.




     There was almost no discussion of methods of collecting tissue




and sediment samples.  What discussion occurred centered around the




idea that EPA needs a written set of guidelines regarding the col-




lection of these types of samples.




     Discussions on the methods of preserving samples quickly revealed




an almost total lack of knowledge regarding the effects of various




alternative methods of preservation.  In general, most laboratories




simply place bottled-grab samples on ice for shipment as a means of




preservation.  However, it was clear that no one really knew whether




this approach is effective in preserving samples containing a variety




of industrial-organic compounds.               '




     Some attendees suggested the use of solvent in sample bottles as a




means of preservation.  There was, however, little agreement as to which




solvent should be used.  For low-boiling pollutants, the use of hexa-




decane as a keeper solvent seems to have some utility.  Various solvents,




including methylene chloride, Freon TF, hexane, isooctane, etc., were

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suggested for use as keepers for higher-boiling pollutants.  Some form




of keeper in the bottle would seem desirable to reduce possible loss




by volatilization as discussed previously.




     Petroleum-containing samples are preserved by the addition of




sulfuric acid [M. Gruenfeld, Env. Soi.  Teohnol. 3 7, 636 (1973)], while




formalin was suggested for PCB-containing samples [T. A. Bellar and




J. J. Lichtenberg, "Some Factors Affecting the Recovery of PCB's From




Water and Bottom Samples," CIC-CCIW Symposium on Water Quality Parameters,




Burlington, Ontario, November, 1973].  Copper sulfate and phosphoric acid




are often used to preserve samples for phenols analysis.




     Tissue- and bottom-sediment samples are preserved by freezing by




almost all represented labs.  A recent paper [Butler, Pest. Monitor1. J.t




6, 238 (1963)] reported the use of a mixture of 90 percent anhydrous




sodium sulfate and 10 percent Quso G30 (micro-fine precipitated silica)




to preserve field-blended-tissue samples.  This method allowed the




storage of desiccated-tissue samples for at least 14 days without loss




or degradation of pesticide residues.




     This area of preservation of samples is another highly important




area requiring extensive research.  Hopefully, the various EPA research




groups will expend the needed effort to define suitable preservation




techniques for both water and other samples.

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                                                                  10
                     II.  EXTRACTION PROCEDURES




     Extraction procedures cover a wide variety of techniques whereby


the organic pollutant(s) of interest are transferred from the inorganic


or biological matrix (i.e., water, sediment, or tissue) and usually


concentrated prior to chemical characterization.  During the Workshop,


extraction techniques were discussed for separating organic pollutants


from water and wastev/ater samples, tissue, bottom sediment, and sludge


samples.


     The simplest situation occurs when no extraction is required.  In


this case, the chemist may apply such techniques as direct aqueous-


injection gas chromatography, head-space analysis, trapping of volatile


components by either gas purging or cold trapping and finally, steam


distillation.


     The technique of direct aqueous-injection gas chromatography (GC)


was familiar to most workshop participants.  Those who had applied it had


found it most useful for the analysis of volatile organics in effluents


where the detection limit of approximately 1 mg/1 is adequate.  The use


of pre-columns to prevent salts and other non-volatiles from damaging


the GC column was recommended by several participants.  Quartz inserts


or lengths of column tubing at the head of the GC column, either empty


or packed with quartz wool, can be employed for this purpose.  These


inserts can be changed or cleaned with a minimum of effort.  Direct
                          *

aqueous injection is currently being recommended by the EPA Methods


Development and Quality Assurance Research Laboratory (MDQARL) in the


analysis for chlorinated and aliphatic solvents.  For these analyses,

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                                                                  11





the halogen specific micro-coulometric or the non-specific flame




ionization detectors are employed.  Direct aqueous injection is recom-




mended by ASTM for the analysis of phenols in their "Standard Method




of Test for Phenols in Water by Gas Liquid Chromatography" (D2580) and




for the analysis of volatile organic matter in water in their Method




(D2908).  Additional methods of direct aqueous injection for organic




acids, nitrites, and aliphatic hydrocarbons are presently being pre-




pared by ASTM and others [D. Brown, AQC Newsletter", (19), 5 (1973)].




     Head-space analysis can also be applied for the determination of




volatile-organic materials although few of the Workshop participants




had actually employed it in practice.  The use of infrared spectro-




scopy has been reported for the quantitative identification of head-




space gases in oil samples.




     Other techniques for the analysis of volatile organics use gas




purging to remove volatiles from the samples.  Tom Bellar reported the




use of nitrogen gas to purge volatile-organic components from water




samples.  The evolved organics are then collected on an adsorbent




column (Chromosorb 103).  The collection column is then inserted into




the injection port of a gas chromatograph and the trapped components




analyzed under temperature-program conditions.  The technique has been




applied to a variety of chlorinated and non-chlorinated aromatic ami




aliphatic solvents.  Under ambient conditions, the recovery of relatively




insoluble organic compounds -has been found more efficient than the




recovery of highly water-soluble compounds.  Instead of collecting




the purged volatile-organics on a column, the materials may be col-




lected in a cold trap.  This technique has been used by several of the

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                                                                 12






laboratories in attendance and is a relatively common technique in the




analysis of atmospheric samples.




     Steam distillation can be used to reduce the sample volume and to




concentrate organic components that are volatile under such conditions.




Samples thus concentrated can be analyzed by direct-aqueous injection




or by solvent extraction prior to GC or other types of detection.




However, possible hydrolysis of sample components must be carefully




considered when ever this technique is employed.




     Liquid-liquid extraction is by far the most common type of extrac-




tion technique in dealing with water and wastewater samples.  The Work-




shop participants were queried as to the most common types of solvents




used for this purpose and it was found that the solvents most commonly




used were methylene chloride or chloroform, follox^ed by ethyl ether,




hexane, methylene chloride-hexane, and finally by ethyl ether-hexane




mixture.  Other solvents that were mentioned but not widely used, were




carbon tetrachloride for oils, freon for oils, benzene-hexane, hexane-




acetone and hexadecane.  A consensus of the Workshop participants was




that, whenever possible, non-flammable solvents such as methylene




chloride or freon should be used.  The potential explosive hazard of




diethyl ether and other flammable solvents should not preclude there




use when needed.  However, the chemist must be aware of the hazard and




take measures to minimize the possibility of accident.  Obviously, the




solvent of choice will depend upon the types of pollutants to be analyzed




or to be characterized.




     In the case where a wide variety of organic types are to be deter-




mined, liquid-liquid extraction can be used as a fractionation tool as

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                                                                 13
well as a separation technique.  A procedure for the separation of




neutrals, acids, and bases was described by William Loy of the Southeast




Water Laboratory.  In this procedure, conditions for the initial extrac-




tion of the sample are determined by the pH of the sample as received.




The sample is shaken to provide homogeneity and is divided into two equal




portions for replicate analysis.  If the pH of the sample is between




5 and 14, the sample is initially extracted with hexane to recover the




"neutral organics" which are then analyzed by gas chromatography.  After




the neutrals have been removed, the sample is then acidified to pH 2 and




extracted with methylene chloride.  The methylene chloride extract is




then concentrated and divided equally.  One aliquot is analyzed directly




by gas chromatography, the second is esterified, using diazomethane prior




to analysis by gas chromatography.  If the original sample has a pH less




than 5, the sample is acidified to pH 2 and extracted only with methylene




chloride.  The methylene chloride extract is then divided and analyzed




or esterified as above.  In some cases, organic bases may be recovered




by adjusting the pH of the sample to greater than 10 and extracting with




methylene chloride or other appropriate solvent.  Extraction of the




samples may be carried out using separately funnels or a magnetic stir-




ring device.  The magentic stirring approach is satisfactory when




extracting with a lighter-than-water solvent; it is not very efficient




when using a solvent that is heavier than water.




     A good discussion of liquid-liquid extraction can be found in the




ASTM Manual, Part 23, Method D-2778 "Solvent Extraction of Organic




Matter from Water".  This method describes a general approach that will

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                                                                   14






separate a wide variety of organic components and allows the analyst




to select from a variety of solvents as required to meet his needs.




     Workshop participants reported that recoveries from industrial




waste samples were variable and often poor.  Salting out was suggested




as a method for improving recovery.  The use of sub-ultrasonic (polytron)




or ultrasonic treatment to break up the suspended solids in a sample was




also suggested as a means of improving the extraction efficiency.  It




should be noted that heavier-than-x^ater solvents can cause problems




during phase separation when the samples contain fibers for other solid




materials that tend to settle to the bottom.




     A procedure for breaking emulsions by pouring the sample through




glass wool was presented to the Workshop by William Loy.  The procedure




calls for passing the organic layer through a column of 2-3 inches of




Pyrex glass wool (prerinsed with methylene chloride) and collecting it




in a beaker.  If necessary, the solvent is forced through the glass wool




by applying mild air pressure.  If a layer of water is present after




passing through the glass wool once, it is passed through a second




column for final drying.  Some unanswered questions regarding this tech-




nique are the following: Are organics that may be occluded in emulsi-




fied material lost as this material is removed by the glass wool?  Does




the glass wool do an adequate job of removing the water from the solvent




extract?  Mr.  Loy is working to answer these and other questions.




     Sulfur is often extracted from environmental samples into the




organic layer.  In order to avoid sulfur interference, the sulfur may be




removed with mercury or copper powder (Bull. Fnviron. Cent, and Toxic.,




6, 9(1971).

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                                                                  15






     An alternate approach for recovery of organic pollutants from




vrater and wastewater is adsorption on organic resins or activated




carbon followed by solvent extraction of the resin or carbon to desorb




the organic pollutants of interest.  A number of Workshop participants




have used the Rohm and Haas XAD resins for the recovery of a variety




of organic compounds.  Though this relatively new technique is not yet




fully developed, it has shown considerable promise for some applications.




A preliminary literature review of work with this technique has been




prepared by Roger Tindle, NFIC-Denver.




     Investigations of procedures for extracting organic materials from




the XAD resins are in progress.  A number of solvents have already been




applied singly, in series, or as mixtures.  Examples are acetone, methanol,




or ethanol used singly or acetone followed by methylene chloride followed




by acetone again in series, or a single elution using a mixture of acetone




in chloroform.  Some degree of class separation based upon pH can be




achieved using the resins, however, more work needs to be done in this




area.  Some of the problems surrounding the use of the resins are the




same as those encountered for the carbon adsorption technique.  These




include, variable particle size, background interference, unknown ef-




ficiency, plugging by suspended matter, etc.; however, there are a




number of decided advantages of the resin over the carbon such as lack




of active sites which minimize chemical changes on the resin surface.




     Polyurethane foams have also been employed with the extraction of




certain organics from water.  In general, the foams have been found to




work well for the extraction of non-polar compounds, e.g., PCB's; how-




ever, they are not very effective for the extraction of more polar

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                                                                  16
compounds.  A combination of the XAD resins and the polyurethane foams




have been applied by NFIC-Denver with good success.




     Historically, carbon adsorption has been widely used for the




separation of organic components from water.  However, due to its non-




quantitative nature, expense of sampling, etc. it has fallen into disuse.




The normal procedure for removing organics from carbon has been air




drying of the carbon, followed by extraction first with chloroform fol-




lowed by extraction with alcohol.  Dr. Clark Allen reported at the Work-




shop that a considerable increase in extraction efficiency can be obtained




if the carbon is dried by freeze drying instead of air drying.  Apparently,




much greater removal of water is obtained this way and more thorough con-




tact is achieved between the carbon and the extraction solvent.  Although




the Methods Development and Quality Assurance Research Laboratory has now




terminated surveillance operations using the carbon adsorption technique,




there is still some interest among the Regions in the use of this tech-




nique for separating and identifying organic compounds from water.




     A number of the EPA laboratories have found the need, on occasion,




to analyze tissue samples for organic chemical pollutants.  It is anti-




cipated that the need for this type of activity will be increased since,




especially from an enforcement standpoint, there is a legal necessity




to demonstrate the effects of pollutants on the environment.  Measuring




the uptake of chemical pollutants by aquatic life is one way to demon-




strate this.




     The extraction of tissue samples for organic pollutants is con-




siderably different from the extraction of water and wastewater samples.

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                                                                 17
Most work in this area has centered around the analysis for pesti-




cides and/or petroleum products.  Certain types of organic pollutants,




such as oils, can be extracted by adding an organic solvent while the




tissue sample is being masserated in a blender.  This technique has




been found to be especially useful when using sub-ultrasonic mixers,




such as the Polytron (Brinkman instruments) and the Tissu-Mizer (Tek-




Mar Company).  Several Workshop participants have investigated this




technique and feel that it shows promise for certain applications




[J. Agv.  Food Chem.  20. 48, (1972)].




     Blenders can also be used to prepare samples for column extraction.




For this technique,  the sample is ground in the presence of dry ice




and sodium sulfate [J.  Agr. Food Chem., 18, 948, (1970)].  Following




grinding, the dry ice is allowed to sublime from the sample leaving a




fine powdery material.   Once the tissue has been dried in this fashion,




it can be packed in a chroraatographic column and extracted by elution




with a solvent such as acetone, methanol, or acetone-haxane (1:1) [(Bull.




Envir.  Contam.  Toxi., 7_, 1151, (1972) and Southeast Water Laboratory,




EPA, Athens, Georgia, Method No. SP-8/71].  An alternate technique is




freeze drying the tissue samples.  Dr. A. Wilson of EPA's Gulf Breeze




Laboratory has used this method for preparation of phytoplankton samples.




     Tissue samples  can also be extracted by use of a soxhlet extrac-




tor.  This seems to be about as commonly applied as the column extrac-




tion technique.   Some of the solvents employed for soxhlet extraction are




petroleum ether, methylene chloride, acetone-hexane, methylene chloride-




hexane, acetonitrile, ethyl acetate, and acetone-benzene.  The use of

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                                                                  18





phosphoric acid acetone (1:2) has been used for the extraction of




pentachlorophenols.




     Bottom sediment and sludge samples can be extracted by techniques




that are similar to those applied to tissue samples, namely, column




extraction, soxhlet extraction and blender extraction.  Sample pre-




treatment, however, varies depending upon whether the extraction is to




be done under wet or "dry" conditions.  Workshop participants discussed




five different approaches to pre-treatment, namely: 1) air drying at




ambient conditions, followed by grinding with a mortar and pestle and




addition of 10 percent water followed by soxhlet extraction; 2) partial




air drying (30-40 percent moisture) at ambient conditions and blending




with sodium sulfate followed by column extraction; 3) decanting excess




water and blending the wet sample with sodium sulfate followed by column




extraction; 4) decanting excess water and extracting the wet sample by




shaking with solvent using no dessicant; and 5) blending of the wet sample




directly with solvent.




     Once a sample has been "dried" it may then be extracted either by




column elution or soxhlet extraction.  Solvents normally employed are




acetone-hexane, acetonitrile-hexane, methylene chloride, acetonitrile,




ethyl acetate, and acetone-benzene.  Soxhlet extraction of sediment




samples has been described many times ("The Identification and Measure-




ment of Chlorinated Hydrocarbon Pesticides and Surface Waters", U. S.




Department of the Interior, 1014 Broadway, Cincinnati, Ohio, Publication




WP-22, 1966.)  This technique is found to give good recovery of com-




pounds that are stable and do not volatilize under the conditions of




treatment.

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                                                                 19
     Organic pollutants can be extracted from sediments by mixing directly




with the solvent of choice.  Although no laboratories are presently using




Waring Blenders for this type of extraction, both mechanical shaking




("Methods for the Analysis of Organic Substances in Water", Book 5,




Chapter 83, Techniques of Water Resources Investigations, the U.S.G.S.,




1972.) and sub-ultrasonic mixing are being employed with varying degrees




of success.  The latter technique looks especially promising; however,




further work is required to access its full utility.




     In general, it was concluded at the Workshop that air drying of




the sample is not a good practice when a broad spectrum of organic com-




pounds is to be determined.  Significant amounts of very volatile organic




compounds can be lost if air drying is employed, e.g., BHC has been




found to volitalize readily under these conditions.  On the other hand,




extraction of some compounds from environmentally contaminated sediments




has been significantly more efficient when carried out on an air-dried




sample.  Thomas Bellar of the MDQARL reported that both PCBs and dieldrin




are more efficiently extracted from natural samples that have been dried




in this fashion.




     It was recognized by the Workshop participants that a great deal




of work needs to be done to determine which extraction procedure, if




any, is superior.  However, an even greater area of concern is the wide




variations that occur during sample collection.  It was the general con-




cession that for tissues and sediments, the sampling variations and




biological variations are much larger than analytical variations and




often account for the wide discrepancies in replicate analysis.

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                                                                  20
          III.  FRACTIONATION AND DERIVATIZATION PROCEDURES






     Samples that are too complex to be separated under normal OC con-




ditions are usually subjected to some form of fractionation during, or




after, extraction.  Six workshop attendees reported that they frequently




use some form of acid-base separation for water samples, particularly




industrial effluents.  They preferred to use a simple two- or three-step




scheme although they were aware of Braus, Middleton and Walton's more




complex scheme that separates neutral compounds, strong acids, phenols,




bases and amphoteric compounds [Anal. Ch&n. 23, 1160 (1951)].  Typically,




they extract the sample, as received, to isolate neutral compounds.  Then




they acidify to about pH 2 and extract to isolate acids and phenols.




Phosphoric, sulfuric, or hydrochloric acids are used for this step.  The




aqueous layer is then adjusted to pH greater than 8 with ammonia or




dilute sodium hydroxide to form free bases and the sample is extracted




a third time.




     Some acids and phenols from the acid fraction can be analyzed




without further treatment.  Acetic through hexanoic acids can be




chromatographed directly on Chromosorb 101 in an all-glass system.




Carbowax 20M and FFAP have been used to analyze simple phenols, cresols




and similar materials in paper-mill effluents.  The longer acids and




more complex phenols are usually converted to methyl esters and ethers.




The most commonly used methylating agent is diazomethane.  Phenols




react more completely with this reagent when a little boron trifluoride




in methanol is added as a catalyst.  The extract must not contain any




chloroform because it reacts with diazomethane to form di- and

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                                                                 21
trichlorinated alkanes up to seven carbons long that complicate the GC




analysis.  Methylene chloride does not cause this problem.  A discus-




sion of methylation procedures, including several on-column reagents




is given in the report from SERL on "Current Practice in GC-MS Analysis




of Organics in Water" (EPA-R2-73-277).




     Other groups feel that trimethylsilyl (IMS) derivatives give more




definitive mass spectra than methyl derivatives.  They recommend BSTFA




(N,0-bis-trimethylsilyl trifluoroacetamide) as the reagent of choice.




One trade name is Regisil.  Another derivatization mentioned, but




apparently rarely used, is to form pentafluorobenzyl ethers, thioethers




or esters from phenols, mercaptans and acids.  [Kawahara, Anal. Chem.




40, 1009 and 2073 (1968)].




     In contrast to neutral compounds and acids, very few bases have




been identified in the environment.  The Workshop participants agreed




that judging from manufacturing data, industrial usage and the size of




the basic fractions in past CCE studies, these compounds must be in the




environment but we are not seeing them.  This is a major weakness in




our present analytical techniques.




     Among the bases that have been found are picolines (methyl




pyridine isomers) in river water, dibutyl amine from a latex-additives




plant and quinoline and di- and trimethyl pyridines from a wood-pre-




serving plant.  Several dichloroaniline isomers and other nitrogen




containing compounds in industrial effluents were identified by




NFIC-Denver after conversion to TMS derivatives.  Several aromatic




amines from biological sources were reported as analyzed in good

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                                                                 22
yield by conversion to the amides with pentafluoropropionic anhydride




and analysis by EC-GC.




     Some methods-development work on amines has been done.  Many




simple amines can be gas chromatographed by direct aqueous injection




on Tenax columns.  One report was that Chromosorb 101 can also be used




for this purpose although the 103 material is recommended.  Another




worker found that methyl and dimethyl amines can be sampled by the




headspace-gas technique and then analyzed by GC on OV-101.  Low-




molecular weight amines were also reported as separated from other




impurities by adsorption on weak acid cation exchange resins.




     A wide variety of post-extraction chromatographic cleanup techni-




ques were discussed.  Oils are frequently chromatographed on Florisil




or silica gel in a manner similar to pesticides.  Some use a column




containing silica gel on top of alumina.  This column, deactivated with




4 percent water, was reported to separate oils from sewage when eluted




with carbon tetrachloride.  Another observation was that a useful




second dimension of proof in oil fingerprinting by GC was to separate




the oil into aliphatic, aromatic and oxygenated fractions by eluting




from silica gel with isooctane, benzene and 1:1 chloroform-methanol by




the method of Rosen and Middleton [Anal. Chem., 27, 790 (1955)].  Phenols




can be isolated from carbon chloroform extracts (CCE's) by extracting




the chloroform with base, extracting the acidified-aqueous layer with




ether, and then chromatography on Florisil with ether as the eluting




solvent.

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                                                                 23






     Thin-layer chromatography (TLC) would seem to be a very powerful




technique in view of its low cost, and the visual impact it can have




in a courtroom.  In practice however, it is used little in pollution




analysis because of its lack of discrimination and sensitivity.  Poly-




nuclear aromatic hydrocarbons (i.e., benzopyrene) have been separated




and detected; phenols from CCE's have been detected down to one microgram




per spot, and some amines can be analyzed by TLC.  Identification of




sources of oil spills by TLC has been extensively studied, partially




through EPA grants to Esso and Phillips Petroleum, but there are still




problems with the method.  Two areas for future research on TLC were




suggested  reversed phase TLC for polar compounds, and detection of




specific classes of compounds in industrial effluents by specific spray




reagents.  Nobody seemed to be planning any immediate activity in these




areas.




     Another method mentioned for detecting specific compound groups




was the use of GC subtraction columns.  These are short lengths of




tubing containing a chemical that removes specific compounds.  They




are placed between the GC injector and the column.  Boric acid sub-




tracts alcohols, o-dianisidine subtracts aldehydes and ketones, phos-




phoric acid subtracts epoxides [Beroza, JAOAC, 54, 251 (1971); see




also Chem.  Abst., 74, 134709z (1971)].  No one reported first-hand




experience with this procedure.




     Liquid chromatography as a cleanup method has not been extensively




applied.  It was not an improvement over column techniques for cleanup




of oils for fluorescence analysis.  There was one report of permaphase

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                                                                 24






columns bleeding enough to show up later in GC-MS analysis of the




individual fractions.




     Of at least ten LC's in EPA labs, four have been bought x^ithin




the last year and are too new to be properly evaluated.  It was generally




concluded that a detector breakthrough will have to be made before LC




finds extensive application in pollution analysis.




     Probably the most promising cleanup technique is some form of




automated gel-permeation chromatography.  Gel permeation is not uni-




versally applicable, but it is useful for eliminating interference from




compounds of molecular weights greater than about 700.  One example




cited was in analysis of an oily-fish extract containing PCB's toxaphene




and chlordane.  Gel permeation allowed isolation of the combined pesti-




cide mixture.  Further cleanup on silica gel and alumina was required




before the separate materials could be analyzed.  NFIC-Denver plans to




evaluate the application of gel permeation to industrial effluents.

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                                                                 25






           IV.  QUALITY CONTROL IN THE ORGANIC LABORATORY






     There are two major categories to be considered when discussing




analytical quality control in the organic laboratory.  The first is the




qualitative aspects of the analysis, that is, the degree of certainty




that the unknown constituent has been correctly identified.  The second




category involves the quantitative aspects of the analysis, that is,




the acceptability of the precision and the accuracy of the results




obtained.  A discussion of this subject is presented in the "Handbook




for Analytical Quality Control in Water and Wastewater Laboratories",




Analytical Quality Control Laboratory, Cincinnati, Ohio, 1972.




     In regard to qualitative control, it was recognized by the Workshop




participants that the first step requires checking and eliminating inter-




fering background components from all reagents, solvents, glassware and




other equipment employed in the analysis.  Once the analyst has assured




himself that interferences are not present, he must then recognize that




selective extraction of particular compounds may occur depending upon the




pH of the sample, the solvents used, and other factors.  Consequently,




various separation or "cleanup operations" may be required to provide




additional support for the qualitative identification of specific con-




pounds.  Final qualitative identifications can be achieved by a variety




of techniques.  The current best methods are GC-MS, infrared spectro-




scopy, and multiple column gas chrorato^raphy.  The latter technique




is enhanced when a sendspecific detector sucli as the T7PD or Coulsen




micro-coulometric can be used.  Obviously in all cases of instrumental




analysis, close control nust be maintained of the instrumental parameters,

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                                                                 26
     In regard to the quantitative aspects of quality control, both




replicate and spiked sample analyses must be performed periodically




to assure the precision and accuracy of the test; however, due to the




complexition of organic analysis, time constraints are often the con-




trolling factor in limiting the number of replicates or spiked sample




analyses that can be performed.  As a guide to the types of techniques




that can be employed, several of the Workshop participants described




the quality control procedures that they presently employ in their




laboratories.  These are summarized below.




     William Loy, Chemical Services Branch, Southeast Water Laboratory




 At this laboratory all water samples are analyzed in duplicate.  When




samples are to be analyzed for a broad spectrum of industrial chemicals,




selected samples are spiked with a mixture of six known organic compounds.




These known compounds cover the range of volatile, basic, acidic, and




neutral compounds at a concentration of 100 yg/1 in acetone.  Problems




with recovery have been encountered only when large amounts of particu-




lates are present in the sample.




     James Lichtenberg, Methods Development Quality Assurance Research




Laboratory  In this laboratory one set of duplicate samples is run with




each series that is analyzed, usually one duplicate for every nine samples,




Simultaneously, one sample is dosed with a mixture of known compounds of




the same class as those to be determined and analyzed along with the




other samples.




     Robert White, Wildlife Research Laboratory  In this laboratory,




which deals primarily with tissue analysis, every ninth sample is

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                                                                 27
repeated though not at the same time as the first analysis.  The second




analysis is randomly performed either by the same or different analyst.




When running the repeat analysis, the chemist goes back to his primary




reference standard-stock solution to insure that the standard used in




the initial analysis was accurate.  The results are independently




reviewed by a second analyst before being reported.  Control charts are




maintained for several concentration levels using a computer program




devised by this laboratory.  From time to time, collaborative studies




are conducted with other laboratories.




     Dr. David Stalling, Fish Pesticide Research Laboratory  This




laboratory uses many of the techniques described above; however, they




also use alternate test procedures to check upon the reliability of




the reported results.  Primarily, they use carbon-14 tagged materials




to check each step in the analytical procedures.  With this system, each




analyst is required to withdraw 10 percent of the sample extract obtained




from each step of the analysis, e.g., extraction, concentration, elated




fractions from cleanup steps, etc.  These aliquots are then analyzed by




liquid scintillation and the recovery in each step is determined.  These




results are then compared with the results obtained by routinely applied




techniques, such as gas chromatography.  So far, the technique has been




applied primarily for quality control during tissue analysis and for




such analysis, no GC interference is noted at the dosing levels required.




However, in the analysis of the low levels of organics found in natural




waters, such an interference may be a problem.

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                                                                 28
     This approach to quality control appears to be quite intriguing,




especially because once it is set up it is very easy to operate.  Liquid




scintillation counting requires a minimal amount of time and effort.




Consequently, much more quality control information can be gathered




than by conventional techniques.  One of the main problems with this




technique is the cost of the carbon-14 labeled compounds and the




accessibility of a liquid scintillation counter.  It is not incon-




ceivable, however, that one central location could provide this service




to many of the EPA laboratories.




     A variety of other techniques were discussed by the Workshop




participants which should help in the quality control program.  For




example, several of the participants use internal standards for both




qualitative and quantitive purposes.  In one laboratory, a known




reference standard equivalent to the tentatively identified unknown




is added to the sample and the gas chromatographic response compared




to that produced by the reference standard alone.  In another case,




the response factor of a selected internal standard (not the same as




the compound identified) relative to the compound to be identified is




determined.  This factor is then used for future calculations of the




quantitative results.




     In the quantitation of gas chromatographic peaks, it was generally




observed by the Workshop participants that peak area is more accurate




for later eluting peaks.  Peak height, however, is best for very early




eluting peaks.  It should be noted that the volume of an injection




affects the peak width and therefore the injected volume should be

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                                                                 29







close to the same for both the sample and reference standard.  In all




cases, the detector must be operated within its linear range.




     Sample injection technique is critical during gas chromatographic




analysis.  A number of laboratories use the solvent-flush technique




in which a small volume of pure solvent is pulled up into the barrel




of the syringe before the sample.  Upon injection, this pure solvent




flushes all the sample from the needle and complete transfer of the




sample is assured.  When they are available, automatic sample injectors




have been found to give very reproducible results and their use should




be encouraged whenever possible.  In all cases, the analyst is encouraged




to use the technique best suited to him.

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                                                                 30
                        V.  GENERAL COMMENTS






     A variety of items not covered in the preceding chapters were




brought up during the general discussion period of the Workshop.  Some




of these items are summarized below in varying detail.




     A number of Workshop participants were greatly interested in the




proposed list of Toxic Substances [Federal Register, Vol. 38, No. 173,




Sept. 7, 1973)].  Much of this interest x?as in the form of concern for




the brevity of the proposed list and questions as to why the materials




listed were the ones chosen.  As no answers to these questions were




forthcoming, the discussion shifted to analytical procedures for




measuring these toxic substances.




     Most participants agreed that suitable procedures were presently




available for measuring polychlorinated biphenyls and the chlorinated




hydrocarbon pesticides, aldrin, dieldrin, toxaphene, etc.  However,




little information was available regarding the analysis for benzidine




(4,4-diarainodiphenyl) and its salts.




     The MDQARL is presently working on methods for benzidine.  A color-




metric method is currently recommended [M. A. El-Dib, JAOAC, 54, (6),




1383 (1971)]; however, it is not specific for benzidine.  Work is pre-




sently underway on a thin-layer modification of this method and a GC




procedure, both of which would be more specific.  It should be noted




that the free base form of benzidine can be chromatographed on SE-30




columns and also on Tenax columns although some partial adsorption




is observed with the latter.

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                                                                  31



     Benzidine can be removed, from water by carbon adsorption of the


HC1 salt; however, the salt apparently cannot be recovered from the


carbon by chloroform or alcohol extraction.  A search was made of the


CCE extracts on file from the Surveillance Network of the FWPCA, and


no benzidine was found.


     The MDQARL has found that the free base can be quantitatively


extracted from water at pll 10 with chloroform.  Uater samples of


benzidine do not appear to be stable.  Benzidine was found to react


rapidly with Cincinnati tap water (presumably the chlorine) to form a


precipitate.  Even standards, made up with distilled water turned cloudy


within one week.


     An alternate approach was suggested by Dr. David L. Stalling.


Trifluoroacetic anhydride is a good derivatizing agent for amines, and


Dr. Stalling suggests that this reagent may form derivatives with


benzidine that will be easily chromatographed.  This, of course, will


need to be checked.  With no other comments concerning the Toxic Sub-


stance List, the discussion turned to the Ocean Dumping Criteria.


     These Criteria were recently promulgated by EPA.  The Proposed


Criteria appeared in the Federal Register, Vol. 38, No. 94, May 16, 1973


and the Final Criteria were published in the October 15, 1973 Federal


Register,  Vol. 38, No. 198, Part II.  The Criteria lists a number of


potential organic pollutants that require "special consideration" prior

                                
to issuance of a dumping permit.  Consequently, many Workshop partici-


pants felt they may be required at sometime in the future, to analyze


wastes for these materials and, as a result, they were quite interested


in any information as to how to perform such tests.

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                                                                  32





     First on the list were organosilicon compounds.  No one at the




Workshop was aware of any pollution problems associated with organo-




silicon compounds and consequently it was unclear just what compounds




would be of most concern.




     In regard to other organometallic pollutants, it was evident that




little work had been done in this area.  The National Water Quality




Laboratory at Duluth has apparently looked very briefly at organocadmium




and organocopper compounds.  The Edison Laboratory has had some exper-




ience with organolead materials in oil wastes.




     The Ocean Dumping Criteria also listed aliphatic solvents as waste




components that require "special consideration."  A variety of methods




appear to be available for this analysis, namely, direct aqueous injec-




tion, head space analysis, GC analysis of volatile components trapped




on Chromasorb 101 or other material following purge by inert gas, and




finally, extraction with a high-boiling solvent such as hexadecane  fol-




lowed by GC analysis.  The method of choice would depend upon the needs




of the particular laboratory although all the cited procedures seem




workable.




     The Workshop participants felt that they could test for phenols




either by the steam distillation - 4-aminoantipyrine - procedure in




Standard Methods or by the gas chromatographic procedure in the ASTM




Manual, Part 23.




     Plastics, plastic intermediates and byproducts seemed to be an




unknown quantity to the Workshop participants.  Undoubtedly, many




compounds in this category could be identified by gas chromatography/




mass spectrometry following work up procedures previously discussed,

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                                                                 33




i.e., phthalate plasticisers [D. L. Stalling, et. al.t Environmental




Health Prospeatives, 159 (1973)].  However, before additional tests




can be considered, we will need more information concerning just what




compounds in this category actually represent a pollution hazard.




     Analytical procedures for amines were discussed previously.




     Polynuclear aromatic hydrocarbons can be identified by a variety




of procedures.  Several participants felt that the easiest procedures




to apply were colormetric, as recommended by the World Health Organization,




and thin-layer chromatography [E. Sawicki, et. al.3 Health Lab. Sci. 7




(1)68 (1970)] even though the specificity of these procedures is unknown.




In addition, many of the aromatic hydrocarbons can be separated and




identified by gas chromatography.  Participants recommended columns




of OV-1, Dexil, and Apiezon L.  Undoubtedly, others are available.




Liquid chromatography has also been used and appears to hold considerable




promise [N. F. Ives and L. Giuffrida, JAOAC, 55_, (4), 757. (1972)].  In




tissue samples, polynuclear aromatic hydrocarbons can be identified by




fluorescence following a rigorous clean-up procedure [J. W. Howard,




et. al.3 JAOAC, J51, 122 (1968); AOAC Methods3 llth Ed. Si. 001, pg 361




(1971].  From the above discussion, it was evident that a number of




potentially suitable procedures are available, however, at present, none




of the participants had applied any of these tests to industrial waste-




waters, sludges, or dredge spoil.




     Little work has been done on detergents other than extraction of




ABS or LAS by the MBAS tests described in Standard Methods.  The MDQARL




has used TLC procedures to identify polyoxyethylene-type detergents in




CCE extracts from carbon filters [ASTM Special Tech. Pub. No. 448, p 78

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                                                                 34






 (1969)].  No other analytical procedures were mentioned by the Workshop




participants.  This may be a potential-problem area since there are




published references to the extreme toxicity of some surfactants to




aquatic life [n. J. Wildish, and W. G. Carson, Fisheries Research




Board of Canada Report, Series No. 1212, October (1972); D. J. Wildish,




Water Research, 6_, 759 (1972)].




     A brief discussion took place at the Workshop regarding the limiting-




permissible concentrations of pollutants listed in the Criteria.  The




final revision of the Criteria uses the bioassay tests as the basis for




limiting the concentrations of pollutants.  It was generally agreed by




the Workshop participants that neither bioassay nor concentration limits




would be satisfactory by themselves.  Hopefully, sometime in the future,




limitations will be based upon some suitable combination of pollutant




concentrations and bioassay information.




     In regard to bioassay and toxicity studies, it was pointed out that




a number of computer-based information systems are presently available




that store toxicological information.  Should any of the EPA offices




need such information, NFIC-Denver is tied into a number of these library




systems, notably, TOXICON and others, and will be glad to assist in




gathering the necessary data.




     At the conclusion of the Workshop, it was brought out that a real




need exists for some simplified, screening methods of analysis.  Quite




obviously, the complexities and time requirements of detailed organic




analysis of industrial wastes preclude the ability to monitor a large

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                                                                 35
number of waste streams.  Hopefully, procedures can and will be devised




whereby a large number of samples can be quickly screened and only those




that test above a certain level will need to be set aside for detailed




analysis.  Certainly that is a worthwhile goal and we would encourage




any thoughts on the matter.

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