**SW-846 Update V FOUR - i Revision 5** 

**October 2012 CHAPTER FOUR** 

**TABLE OF CONTENTS**

**Section Page** 

**4.1 SAMPLING CONSIDERATIONS 1** 

**4.2 SAMPLE PREPARATION METHODS 13** 

**4.3 DETERMINATION OF ORGANIC ANALYTES 14**

**4.4 IMMUNOASSAY METHODS 17** 

**4.5 MISCELLANEOUS SCREENING METHODS 18**

**4.6 REFERENCES 19** 

**Table**

**4-1 RECOMMENDED SAMPLE CONTAINERS, PRESERVATION**

**TECHNIQUES, AND HOLDING TIMES 9** 

**Appendix A SUMMARY OF UPDATES/CHANGES IN CHAPTER 4 21** **SW-846 Update V FOUR - 1 Revision 5** 

**October 2012 CHAPTER FOUR** 

**ORGANIC ANALYTES**

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for guidance**  **on the allowed flexibility in the choice of apparat us, reagents, and supplies. In addition, unless**  **specified in a regulation, the use of SW-846 method s is not mandatory in response to Federal**  **testing requirements. The information contained in this chapter is provided by EPA as guidance**  **to be used by the analyst and the regulated communi ty in making judgments necessary to meet**  **the data quality objectives or needs for the intend ed use of the data.** 

**4.1 SAMPLING CONSIDERATIONS**

**4.1.1 Introduction**

**Following the initial and critical step of designi ng a sampling plan (Chapter Nine) is**  **the implementation of that plan such that a represe ntative sample of the solid waste (or**  **material) is collected. Once the sample has been co llected it must be stored and preserved**  **to maintain the chemical and physical properties th at it possessed at the time of collection.**  **The sample matrix, type of containers and their pre paration, analytes of interest,**  **preservation techniques, and sample holding time mu st be thoroughly examined in order to**  **maintain the integrity of the samples. This section highlights practices relevant to**  **maintaining sample integrity and representativeness from the time of sampling until**  **analysis is complete. This section is, however, app licable primarily to trace analyses. Some**  **of these considerations may be less relevant for so urce level samples.** 

**4.1.2 Sample Handling and Preservation: General Con siderations** 

**This following sections deal separately with volati le organic chemicals (VOCs) and**  **semivolatile organic chemicals (SVOCs). Refer to Ch apter Two and Table 4-1 of this**  **section for recommended sample containers, sample p reservation, and holding time**  **information. The guidelines in Table 4-1 are intend ed to improve chemical stability in the**  **sample matrix between the time of sample collection and laboratory preparation / analysis**  **by minimizing loss of the analytes of interest from the sample container and limiting**  **biological and/or chemical degradation (** e.g. **, hydrolysis) (Sec. 4.6 Refs 1, 3-6). Sample preservation recommendations for analysis of organi**  **c chemicals almost always include refrigeration or freezing and may also include chem**  **ical preservation (** e.g. **, addition of pH modifier). Improper handling, preservation, and sto**  **rage of samples can negatively impact the representativeness of the field sample data.** **SW-846 Update V FOUR - 2 Revision 5** 

**October 2012 The preservation and holding time information prese**  **nted in Table 4-1 does not represent EPA requirements, but rather is intended**  **solely as guidance. Selection of preservation techniques and applicable holding time**  **s should be based on all available information, including the properties of the analyt**  **es of interest for the project, their anticipated concentration levels, the composition o**  **f the sample matrix itself, and the stated project-specific data quality objectives. A shorter**  **holding time may be appropriate if the analytes of interest are reactive (**  e.g. **, 2-chloroethyl vinyl ether, acrylamide) or the sam ple**  **matrix is complex (** e.g. **, wastewater). Conversely, a longer holding time ma y be appropriate**  **if it can be demonstrated that the analytes of inte rest are not adversely affected from**  **preservation, storage and analyses performed outsid e the recommended holding times.**  **Prior to collecting samples for analysis, the proje ct team may consider existing information**  **and data regarding analyte stability or conduct fie ld screening for the samples to be**  **collected in order to determine how best to preserv e sample integrity for the analytes of**  **interest. The use of site-specific performance eval uation material is a high confidence**  **mechanism to ensure reliability of project data. Th e references in Sec. 4.6 provide**  **examples of study designs that may be useful for th is purpose.** 

**4.1.3 Sample Handling and Preservation for Volatil e Organics** 

**4.1.3.1 VOC Sample Containers**

**The containers used for collecting VOC samples are frequently volatile**  **organics analysis (VOA) vials that are directly com patible with the equipment used**  **for sample preparation and analysis in the laborato ry. Use of these containers for**  **sampling helps minimize loss of VOCs resulting from opening sample containers**  **and/or transferring materials from one container to another. Certified pre-cleaned**  **VOA vials are commonly used as sample containers fo r VOCs and are**  **commercially available from a number of vendors. Th e vials should be absent of**  **burrs around the caps that might prevent the vial f rom sealing, and septa should be**  **lined with a PTFE layer of sufficient thickness to limit diffusion of VOCs out of the**  **vials during storage. PTFE thicknesses of 0.13 to 0 .25 mm have been shown to be** 

**effective. See reference # 18 in Sec. 4.6 below and Sec. A.8 in Method 5035A for**  **more detail. If they are suspected of being a sour ce of interferences, VOA vials**  **and unpunctured septa should be washed with soap an d water and rinsed with**  **distilled de-ionized water. After thoroughly cleani ng the vials and septa, they should**  **be placed in an oven and dried at 100** ° **C for approximately one hour.**

**NOTE : Heating the septa for extended periods of time (**  i.e. **, more than one hour) or at higher temperatures should be avoided, becau**  **se the silicone begins to slowly degrade at 105**  ° **C). Also, punctured silicone backed PTFE lined sept a should**  **generally not be reused, because some VOCs have hi gh affinity for the**  **silicone material, and puncturing the PTFE septum face exposes the gas phase vial**  **contents to the silicone backing material, causing loss of certain VOCs depending**  **on length of exposure time and vial temperature.**

**Air-tight, sealable coring devices (e.g., En Core TM**  **, Core N’ One TM**  **or equivalent) may also be useful for collection and s**  **torage of cohesive soil samples for VOC analysis. These devices are designed to lim**  **it loss of VOCs from samples during cold storage and shipping over a limited tim**  **e frame and for quantitative**

**transfer of solids and associated VOCs into VOA via ls for immediate analysis or**  **further preservation. Their use during field sampli ng of solids helps reduce or**  **eliminate the need to handle solvents or chemical p reservatives in the field and**  **eliminates some shipping restrictions on field samp les that may otherwise contain** **SW-846 Update V FOUR - 3 Revision 5** 

**October 2012 flammable solvents (**  e.g. **, methanol). Additional information regarding stabi lity** 

**studies of VOCs in solid materials stored in sealab le coring devices is contained in**  **the Sec. A.7 of the appendix of Method 5035A and is described in more detail in the**  **sources referenced therein. An ASTM standard practi ce for use of the En Core**  **TM**
**type samplers is also included in the references in Sec. 4.6 below.** 

**4.1.3.2 VOC Sample Collection:**

**When transferring samples into vials, liquids and s olids should be**  **introduced gently to minimize agitation which might drive off volatile compounds. At**  **least two replicate VOA vials should be taken and l abeled immediately for each**  **collected field sample. They should not be filled n ear a running motor or any type of**  **exhaust system because discharged fumes and vapors may contaminate the**  **samples. Replicate vials from a single sampling poi nt may be sealed together in a**  **single plastic bag, but different samples should be segregated into separate plastic**  **bags to prevent contamination of samples with littl e to no VOCs from those with**  **high concentrations. Sample containers may also bec ome contaminated by**  **diffusion of VOCs into the vials through the septa from the surrounding environment**  **during shipment and storage. To monitor for this po tential source of contamination,**  **a trip blank prepared from organic-free reagent wat er (as defined in Chapter One)**  **should be maintained with the samples throughout sa mpling, shipping, and storage.**  **Including activated carbon in the bags containing t he sample vials may help reduce**  **concerns related to these potential sources of samp le contamination.** 

**Improper vial sealing (** e.g. **, due to solids retained on the vial threads) and improper tightening of caps or closing of sealable**  **coring devices are primary factors in the loss of volatiles due to sample collection a**  **ctivities. Sealing surfaces and any closure threads should be inspected to ensure they**  **are free of debris prior to**

**container closure.**

**Procedures should also be established for selection and appropriate use**  **of sample collection devices (i.e., bailer, coring tool, etc.) including appropriate**  **decontamination measures. If the sample comes in co ntact with the sampling**  **device, organic free reagent water may be run throu gh the device and tested as a** 

**field blank.**

**In general, liquid samples should be poured into v ials without introducing**  **any air bubbles into the samples as vials are fille d. Should bubbling occur as a**  **result of violent pouring, the sample should be pou red out and the vial refilled. The**  **vials should be completely filled at the time of sa mpling, so that when the septum**  **cap is fitted and sealed and the vial is inverted, no headspace is visible. The sample**  **should be hermetically sealed in the vial at the ti me of sampling, and not opened**  **prior to analysis to preserve its integrity.**

**4.1.3.3 VOC Sample Preservation and Holding Times:**

**Samples containing analytes that can be subject to biological degradation**  **need to be preserved as soon as possible (preferabl y in the field) to avoid the loss**  **of target analytes. Refrigeration or freezing is a primary means of sample**  **preservation, because rates of biotic and abiotic d egradation decrease with**  **decreasing temperature, and VOCs are also less vola tile at lower temperature.**  **Samples containing analytes that are most subject t o biological degradation (**  e.g.

**, aromatic hydrocarbons) also should be chemically pr**  **eserved (** e.g. **, by addition of SW-846 Update V FOUR - 4 Revision**  **5**

**October 2012 acid), unless they are analyzed immediately. Chemic**  **al preservation may be inappropriate for highly reactive compounds,**  e.g. **, 2-chloroethyl vinyl ether, acrylamide,**  etc. **, since it may accelerate loss by rapid chemical re action. Aqueous**  **samples containing free chlorine should also be pre served with a dechlorinating**  **agent in order to minimize formation of trihalometh anes and other possible** 

**chemical reactions.**

**Although VOA samples may be held for up to 7 days u npreserved or 14**  **days or longer preserved, it is generally not recom mended as good laboratory**  **practice to hold them that long. VOA samples should be run as soon as possible**  **after receipt by the laboratory. Samples in which h ighly reactive compounds (**  e.g.

**, 2-chloroethyl vinyl ether, acrylamide,**  etc. **) are analytes of interest should be analyzed as soon as they are received in the labora**  **tory.**

**4.1.4 Sample Handling and Preservation for Semivol atile Organics, Including**  **Pesticides, PCBs and Herbicides**

**4.1.4.1 Sample Containers for Analysis of Semivol atile Organics** 

**The containers specified for samples intended for a nalysis of semivolatile**  **organic chemicals (SVOCs) are typically constructed of glass with PTFE lined**  **threaded caps. In situations where PTFE liners are not available, solvent-rinsed**  **aluminum foil may be used as a liner. However, acid ic or basic samples may react**  **with the aluminum foil, causing eventual contaminat ion of the sample. Use of new,**  **disposable pre-cleaned and certified containers red uces concerns about**  **contamination from reusing sample containers. Plast ic containers or plastic lids**  **without PTFE liners should not be used for storage of samples due to potential**  **contamination by phthalate esters and other hydroca rbons within the plastic or**  **absorption of any chemicals of concern in the nativ e sample into the container**  **material. If sample containers are suspected of bei ng a source of interferences**  **particularly for low level analysis, they should be soap and water washed followed**  **by rinsing with solvent(s) appropriate for the anal ytes of interest. See Sec. 4.1.6 for**  **specific instructions on glassware cleaning). Caps may be cleaned by solvent**  **rinsing or replaced with new ones. Monitoring for c ontamination introduced from**  **sample containers should be accomplished through pr eparation and analysis of a** 

**method blank.**

**4.1.4.2 Sample Collection for SVOCs**

**Sample containers should be filled with care so as to prevent any portion of**  **the collected samples from coming in contact with t he sampler's gloves, potentially**  **leading to sample contamination. Samples should not be collected or stored in the**  **presence of exhaust fumes. If the sample comes in c ontact with the sampling**  **device, run organic free reagent water through it a nd test this water as a field blank.** 

**4.1.4.3 Sample Preservation and Holding Times for SVOCs** 

**Field samples to be analyzed for SVOCs are typicall y preserved by**  **refrigeration or freezing. In order to minimize opp ortunities for the most labile**  **SVOCs to degrade, these samples are typically recom mended to be solvent**  **extracted shortly after being taken, within 7-14 da ys for many classes of chemicals.**  **However, some classes of SVOCs, like poly-chlorinat ed biphenyls and**  **polychlorinated dibenzodioxins and dibenzofurans ar e very recalcitrant and do not** **SW-846 Update V FOUR - 5 Revision 5** 

**October 2012 readily degrade during refrigerated storage. Sample**  **matrices to be analyzed for these SVOCs have no maximum recommended holding tim**  **e. Depending on the composition of the sample matrix and the levels of**  **concern for the target analytes, other classes of SVOCs (**  e.g. **, polycyclic aromatic hydrocarbons) may also be stable in refrigerated or frozen storage for longer**  **than the maximum holding time recommended in Table 4-1 (see Reference #12 in Sec.**  **4.6 below). However, the composition of the sample matrix can be an importan**  **t determinant of chemical stability, and minimizing the holding time between**  **sampling and solvent extraction is generally a good practice to obtain representati**  **ve data.**

**Solvent extracts of samples should be carefully mai ntained. Solvent**  **extraction generally stabilizes SVOCs, because the chemicals are typically**  **physically removed from the sample matrix, and some loss mechanisms are**  **eliminated (** i.e. **, biological degradation). Holding times of 40 days are recommended** 

**for solvent extracts for most classes of SVOCs. Man y analytes of interest may be**  **stable in solvent for a longer time period even in extracts of complex matrices, but**  **problems maintaining small volumes of very volatile solvent extracts preclude**  **storage of extracts indefinitely, and some SVOCs ma y still chemically degrade or**  **may be slightly volatile in certain solvents.**

**Freezing solvent extracts particularly of complex s ample matrices may**  **cause precipitation of solids resulting from intera ction of some co-extracted sample**  **matrix components. Storing extracts at 0 to 6 o**  **C may limit problems resulting from analyzing extracts containing precipitated solids,**  **like contaminating or clogging the injector syringe or introducing insoluble component**  **s into the flow pathway of the mobile phase. One way to remove precipitated solids**  **from a solvent extract is by filtration with a sub-micron particle size filter m**  **ade of inert material (** e.g. **, PTFE). As with other preparation steps, batch QC samples shou**  **ld be subjected to the same filtration procedure as the field samples in order**  **to assess the cumulative impact of all sample preparation steps on analyte recovery an**  **d evaluate the potential for contamination resulting from all reagents, and othe**  **r materials that come into contact with the samples.** 

**4.1.5 Safety**

**The methods listed in this chapter do not address a ll safety issues associated with**  **their use. The laboratory is responsible for mainta ining a safe work environment and a**  **current awareness file of OSHA regulations regardin g the safe handling of the chemicals** 

**used in these methods. A reference file of material safety data sheets (MSDSs) should be**  **available to all personnel involved in these analys es.** 

**Safety should always be the primary consideration i n the collection and analysis of**  **samples. A thorough understanding of the waste prod uction process, as well as all of the**  **potential hazards of the waste itself, should be in vestigated whenever possible. The site**  **should be evaluated just prior to sampling to deter mine whether any additional safety**  **measures are necessary. Minimum protection of glove s and safety glasses should be worn**  **to prevent sample contact with the skin and eyes. A respirator should be worn even when**  **working outdoors if organic vapors are present. Mor e hazardous sampling missions may**  **require the use of supplied air and special clothin g.** **SW-846 Update V FOUR - 6 Revision 5** 

**October 2012 4.1.6 Cleaning of Reusable Glassware** 

**In order to successfully analyze samples containing components in the parts per**  **billion or lower concentration range, the preparati on of scrupulously clean glassware is**  **necessary. Failure to do so can lead to a myriad of problems interpreting data due to the**  **presence of interferences resulting from contaminat ion. Particular care must be taken with**  **glassware such as Soxhlet extractors, Kuderna-Danis h evaporative concentrators,**  **sampling-train components, or any other glassware t hat comes into contact with an extract,**  **particularly if the extract will be evaporated to a smaller volume. The process of**  **concentrating the compounds of interest in this ope ration may similarly concentrate the**  **contaminating substance(s), which may distort the r esults and complicate data**  **interpretation.**

**The basic cleaning steps are:**

**1. Removal of surface residuals immediately after u se;** 

**2. Hot soak to loosen and float most particulate ma terial;** 

**3. Hot water rinse to flush away floated particulat es;** 

**4. Soak with an oxidizing agent to destroy traces o f organic compounds;** 

**5. Hot water rinse to flush away materials loosened by the deep penetrant soak;** 

**6. Distilled water rinse to remove metallic deposit s from the tap water;** 

**7. Alcohol, e.g., isopropanol or methanol, rinse to flush off any final traces of**  **organic materials and remove the water; and**

**8. Flushing the item immediately before use with so me of the same solvent that**  **will be used in the analysis.**

**Comments regarding each of the eight fundamental st eps are discussed here in the**  **order in which they appeared above:**

**Step 1: As soon as analysis is complete, the glassw are (e.g., beakers, pipettes,** 

**flasks, or bottles) that came into contact with sam ples or standards** 

**should be flushed with water and then alcohol or ot her appropriate**  **solvent before it is placed in the hot detergent so ak. Otherwise, the soak**  **bath may serve to contaminate all other glassware p laced therein.** 

**Step 2: The hot soak consists of a bath of a suitab le detergent in water at 50**  ° **C**

**or higher. The detergent, powder or liquid, should be entirely synthetic**  **and not a fatty acid base. There are very few areas of the country where**  **the water hardness is sufficiently low to avoid for mation of some**  **hard-water scum resulting from the reaction between calcium and**  **magnesium salts with a fatty acid soap. This hard-w ater scum or curd**  **would have an affinity particularly for many chlori nated compounds and,**  **being almost wholly water-insoluble, would deposit on all glassware in the** 

**bath in a thin film. SW-846 Update V FOUR - 7 Revision**  **5**

**October 2012 There are many suitable detergents on the wholesale**  **and retail market. Most of the common liquid dishwashing detergents so**  **ld at retail are satisfactory but are more expensive than other comp**  **arable products sold industrially. Alconox, in powder or tablet form, is**  **manufactured by Alconox, Inc., New York, and is marketed by a numbe**  **r of laboratory supply firms. Sparkleen, another powdered product,**  **is distributed by Fisher Scientific Company.** 

**Step 3: No comments.**

**Step 4:** Chromic acid should not be used to clean glassware. **Commercial,**

**non-chromate products (e.g., Nochromix) may be used in place of**  **chromic acid, if adequate cleaning is documented by an analytical quality**  **control program. Chromic acid should also not be us ed with plastic** 

**bottles.**

**The potential hazards of using chromic-sulfuric aci d mixture are great and**  **have been well publicized. There are now commercial ly available**  **substitutes that possess the advantage of safety in handling. These are**  **biodegradable concentrates with a claimed cleaning strength equal to the**  **chromic acid solution. They are alkaline, equivalen t to roughly 0.1 N**  **NaOH upon dilution, and are claimed to remove dried blood, silicone**  **greases, distillation residues, insoluble organic r esidues,**  etc. **They are**

**further claimed to remove radioactive traces and wi ll not attack glass or**  **exert a corrosive effect on skin or clothing. One s uch product is "Chem**  **Solv 2157," manufactured by Mallinckrodt and availa ble through**  **laboratory supply firms. Another comparable product is "Detex," a product**  **of Borer-Chemie, Solothurn, Switzerland. Other simi larly effective**  **products are Nochromix (Godax Laboratories) and Con trad 70 (Decon**  **Labs).**

**Steps 5, 6, and 7: No comments.**

**Step 8: There is always a possibility that between the time of washing and the** 

**next use, the glassware could pick up some contamin ation from either the**  **air or direct contact. To prevent this, it is good practice to flush the item**  **immediately before use with some of the same solven t that will be used in**  **the analysis.**

**The drying and storage of the cleaned glassware is of critical importance**  **to realize the benefit of scrupulous cleaning. Pegb oard drying is not**  **recommended. It is recommended that laboratory glas sware and**  **equipment be dried at 100** ° **C. Under no circumstances should such small items be left in the open without protective coveri**  **ng. Otherwise, dust and soot in a laboratory environment can re-contaminate**  **the clean glassware.**

**As an alternative to solvent rinsing, glassware may be heated to a** 

**minimum of 300** ° **C for sufficient time to vaporize any residual orga nic** 

**chemicals. Glassware should be allowed to cool full y before use. This**  **high temperature treatment should not be used on vo lumetric glassware,**  **glassware with ground glass joints, or sintered gla ssware.** **SW-846 Update V FOUR - 8 Revision 5** 

**October 2012 4.1.7 High concentration samples** 

**Cross contamination of trace concentration samples may occur when prepared in**  **the same laboratory with high concentration samples . Ideally, if both type samples are**  **being handled, a laboratory and glassware dedicated solely to the preparation of high**  **concentration samples would be available for this p urpose. If this is not feasible, as a**  **minimum when preparing high concentration samples, disposable glassware should be**  **used or, at least, glassware dedicated entirely to the high concentration samples. Avoid**  **cleaning glassware used for both trace and high con centration samples in the same area.** **SW-846 Update V FOUR - 9** **Revision 5 October 2012** **TABLE 4-1 RECOMMENDED SAMPLE CONTAINERS, PRESERVATION TECHNIQ** **UES, AND HOLDING TIMES a** **(Note: Footnotes are located on the last page of t he table.)** **VOLATILE ORGANICS Sample Matrix** **Container 1** **Preservative 2** **Holding Time 3** **Concentrated waste samples** **Method 5035: See the method. Method 5021: See the method.** **Methods 5031 and 5032: See the methods. Use PTFE-lined lids for all procedures.** **Cool to**≤**6**°**C. 14 days** **Aqueous samples with no residual chlorine present** **Methods 5021, 5030, 5031, and 5032: 2 x 40-mL vials with PTFE-lined septum caps** **Cool to**≤**6**°**C and adjust pH to less than 2 with H** **2 SO** **4 , HCl, or solid NaHSO** **4 If carbonaceous materials are present, or if** **MTBE and other fuel oxygenate ethers are present and a high temperature sample** **preparative method is to be used, do not acid preserve the samples.** **If compounds that readily degrade in acidified water (e.g., 2-chloroethyl vinyl ether** **b ) are** **analytes of interest, collect a second set of samples without acid preservatives and** **analyze as soon as possible. 14 days** 7 days7 days**TABLE 4-1 (continued) RECOMMENDED SAMPLE CONTAINERS, PRESERVATION TECHNIQ** **UES, AND HOLDING TIMES a** **SW-846 Update V FOUR - 10** **Revision 5 October 2012** **VOLATILE ORGANICS (continued)** **Sample Matrix Container** **1 Preservative** **2 Holding Time** **3 Aqueous samples WITH** **residual chlorine present Methods 5021, 5030, 5031, and 5032:** **2 x 40-mL vials with PTFE-lined septum caps Collect sample in a 125-mL container which** **has been pre-preserved with 4 drops of 10% sodium thiosulfate solution. Gently swirl to mix** **sample and transfer to a 40-mL VOA vial. Cool to** ≤**6**°**C and adjust pH to less than 2 with H** **2 SO** **4 , HCl, or solid NaHSO** **4 .** **If carbonaceous materials are present, or if MTBE and other fuel oxygenate ethers are** **present and a high temperature sample preparative method is to be used, do not** **acid preserve the samples. If compounds that readily degrade in acidified** **water (e.g., 2-chloroethyl vinyl ether b** **) are analytes of interest, collect a second set of** **samples without acid preservatives and analyze as soon as possible.** **14 days**7 days7 days**Acrolein and Acrylonitrile Aqueous samples** **Methods 5021, 5030, 5031, and 5032: 2 x 40-ml vials with PTFE-lined septum caps** **Adjust to pH 4-5. Cool to**≤**6**°**C. These compounds are highly reactive and** **should be analyzed as soon as possible. 7 days** **Solid samples (e.g. soils, sediments,** **sludges, ash) Method 5035: See the method.** **Method 5021: See the method. Methods 5031 and 5032: See the** **methods. See the individual methods.** **If compounds that may be reactive in acidified soils (e.g., vinyl chloride, styrene, 2-chloroethyl** **vinyl ether) are analytes of interest, collect a second set of samples without acid** **preservatives and analyze as soon as possible.** **14 days 7 days** **TABLE 4-1 (continued) RECOMMENDED SAMPLE CONTAINERS, PRESERVATION TECHNIQ** **UES, AND HOLDING TIMES a** **SW-846 Update V FOUR - 11** **Revision 5 October 2012** **SEMIVOLATILE ORGANICS/ORGANOCHLORINE PESTICIDES AND HERBICIDES** **Sample Matrix Container** **1 Preservative** **2 Holding Time** **3 Concentrated waste** **samples 125-mL wide-mouth glass with PTFE-lined** **lid Cool to** ≤**6**°**C. Samples extracted** **within 14 days and extracts analyzed** **within 40 days following extraction.** **Aqueous samples with no residual chlorine present** **4 x 1-L amber glass container with PTFE-lined lid, or other size, as appropriate,** **to allow use of entire sample for analysis. Cool to** ≤**6**°**C. Samples extracted** **within 7 days and extracts analyzed** **within 40 days following extraction.** **Aqueous samples WITH residual chlorine present** **4 x 1-L amber glass container with PTFE-lined lid, or other size, as appropriate,** **to allow use of entire sample for analysis. Add 3-mL 10% sodium thiosulfate solution per** **gallon (or 0.008%). Addition of sodium thiosulfate solution to sample container may be** **performed in the laboratory prior to field use. Cool to** ≤**6**°**C. Samples extracted** **within 7 days and extracts analyzed** **within 40 days following extraction.** **Solid samples (e.g. soils, sediments,** **sludges, ash) 250-mL wide-mouth glass container with** **PTFE-lined lid Cool to** ≤**6**°**C. Samples extracted** **within 14 days and extracts analyzed** **within 40 days following extraction.** **TABLE 4-1 (continued) RECOMMENDED SAMPLE CONTAINERS, PRESERVATION TECHNIQ** **UES, AND HOLDING TIMES a** **SW-846 Update V FOUR - 12** **Revision 5 October 2012** **POLYCHLORINATED BIPHENYLS, POLYCHLORINATED DIBENZO-**p**-DIOXINS, AND POLYCHLORINATED DIBENZOFURANS Sample Matrix** **Container 1** **Preservative 2** **Holding Time 3** **Concentrated waste samples** **125-mL wide-mouth glass with PTFE-lined lid** **None None** **Aqueous samples with no residual chlorine present** **4 x 1-L amber glass container with PTFE-lined lid, or other size, as appropriate,** **to allow use of entire sample for analysis. Cool to** ≤**6**°**C. None** **Aqueous samples WITH residual chlorine present** **4 x 1-L amber glass container with PTFE-lined lid, or other size, as appropriate,** **to allow use of entire sample for analysis. Add 3-mL 10% sodium thiosulfate solution per** **gallon (or 0.008%). Addition of sodium thiosulfate solution to sample container may be** **performed in the laboratory prior to field use. Cool to** ≤**6**°**C None** **Solid samples (e.g. soils, sediments,** **sludges, ash) 250-mL wide-mouth glass container with** **PTFE-lined lid. Cool to** ≤**6**°**C. None** **a The information presented in this table does not r** **epresent EPA requirements, but rather it is intende d solely as guidance. Selection of containers,** **preservation techniques and applicable holding time s should be based on the stated project-specific da** **ta quality objectives. b** **See References 1-10 for the preservation and holdin g times studies for volatile organics and the Janua** **ry and February 2012 RCRA Organic Workgroup discussion for preservation and holding times for v** **inyl chloride, styrene and 2-chloroethyl vinyl ethe r in aqueous samples.** **1 PTFE** **lined caps are acceptable for all recommended conta iner types. Additional replicate sample containers** **should also be collected to perform all necessary laboratory quality assurance / qualit** **y control audits (**e.g.**, duplicate, matrix spike / matrix spike duplicate QC samples).** **2 The exact sample, extract, and standard storage tem** **perature should be based on project-specific requir ements and/or manufacturer's** **recommendations for commercially available standard s. Furthermore, alternative storage temperatures ma** **y be appropriate based on demonstrated analyte stability in a given matrix, provided the s** **tated data quality objectives for a project-specifi c application are still attainable.** **3 A longer holding time may be appropriate if it can** **be demonstrated that the reported analyte concentra tions are not adversely affected from** **preservation, storage and analyses performed outsid e the recommended holding times.** **SW-846 Update V FOUR - 13 Revision 5**

**October 2012 4.2 SAMPLE PREPARATION METHODS** 

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for**  **guidance on the allowed flexibility in the choice o f apparatus, reagents, and supplies. In**  **addition, unless specified in a regulation, the use of SW-846 methods is not mandatory in**  **response to Federal testing requirements. The infor mation contained in each procedure is**  **provided by EPA as guidance to be used by the analy st and the regulated community in**  **making judgments necessary to meet the data quality objectives or needs for the intended** 

**use of the data.**

**4.2.1 Extractions and preparations**

**The following methods are included in this section:**

Method 3500C: **Organic Extraction and Sample Preparation**

Method 3510C: **Separatory Funnel Liquid-Liquid Extraction**

Method 3511 **: Organic Compounds in Water by Microextraction**

Method 3520C: **Continuous Liquid-Liquid Extraction**

Method 3535A: **Solid-Phase Extraction (SPE)**

Method 3540C: **Soxhlet Extraction**

Method 3541: **Automated Soxhlet Extraction**

Method 3542: **Extraction of Semivolatile Analytes Collected Usin g Method** 

**0010 (Modified Method 5 Sampling Train)**

Method 3545A: **Pressurized Fluid Extraction (PFE)**

Method 3546: **Microwave Extraction**

Method 3550C: **Ultrasonic Extraction**

Method 3560: **Supercritical Fluid Extraction of Total Recoverabl e Petroleum** 

**Hydrocarbons**

Method 3561: **Supercritical Fluid Extraction of Polynuclear Arom atic** 

**Hydrocarbons**

Method 3562: **Supercritical Fluid Extraction of Polychlorinated Biphenyls** 

**(PCBs) and Organochlorine Pesticides**

Method 3570 **: Microscale Solvent Extraction (MSE)**

Method 3571: **Extraction of Solid and Aqueous Samples for Chemic al Agents** 

Method 3572: **Extraction of Wipe Samples for Chemical Agents**

Method 3580A: **Waste Dilution**

Method 3585: **Waste Dilution for Volatile Organics**

Method 5000: **Sample Preparation for Volatile Organic Compounds**

Method 5021A: **Volatile Organic Compounds in Soils and Other Soli d Matrices** 

**Using Equilibrium Headspace Analysis**

Method 5030B: **Purge-and-Trap for Aqueous Samples**

Method 5031: **Volatile, Non-purgeable, Water-Soluble Compounds b y** 

**Azeotropic Distillation**

Method 5032: **Volatile Organic Compounds by Vacuum Distillation**

Method 5035: **Closed-System Purge-and-Trap and Extraction for Vo latile** 

**Organics in Soil and Waste Samples SW-846 Update V FOUR - 14 Revision 5** 

**October 2012** Method 5041A: **Analysis for Desorption of Sorbent Cartridges from Volatile** 

**Organic Sampling Train (VOST)**

**4.2.2 Cleanup**

**The following methods are included in this section:**

Method 3600C: **Cleanup**

Method 3610B: **Alumina Cleanup**

Method 3611B: **Alumina Column Cleanup and Separation of Petroleum Wastes** 

Method 3620C: **Florisil Cleanup**

Method 3630C: **Silica Gel Cleanup**

Method 3640A: **Gel-Permeation Cleanup**

Method 3650B: **Acid-Base Partition Cleanup**

Method 3660B: **Sulfur Cleanup**

Method 3665A: **Sulfuric Acid/Permanganate Cleanup**

**4.3 DETERMINATION OF ORGANIC ANALYTES**

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for**  **guidance on the allowed flexibility in the choice o f apparatus, reagents, and supplies. In**  **addition, unless specified in a regulation, the use of SW-846 methods is not mandatory in**  **response to Federal testing requirements. The infor mation contained in each procedure is**  **provided by EPA as guidance to be used by the analy st and the regulated community in**  **making judgments necessary to meet the data quality objectives or needs for the intended** 

**use of the data.**

**4.3.1 Gas chromatographic methods**

**The following methods are included in this section:**

Method 8000D: **Determinative Chromatographic Separations**

Method 8011: **1,2-Dibromoethane and 1,2-Dibromo-3-chloropropane by** 

**Microextraction and Gas Chromatography**

Method 8015C: **Non-halogenated Organics by Gas Chromatography**

Method 8021B: **Aromatic and Halogenated Volatiles by Gas Chromato graphy** 

**Using Photoionization and/or Electrolytic Conductiv ity** 

**Detectors**

Method 8031: **Acrylonitrile by Gas Chromatography**

Method 8032A: **Acrylamide by Gas Chromatography**

Method 8033: **Acetonitrile by Gas Chromatography with Nitrogen-P hosphorus** 

**Detection**

Method 8041A: **Phenols by Gas Chromatography**

Method 8061A: **Phthalate Esters by Gas Chromatography with Electr on** 

**Capture Detection (GC/ECD)**

Method 8070A: **Nitrosamines by Gas Chromatography**

Method 8081B: **Organochlorine Pesticides by Gas Chromatography SW-846 Update V FOUR - 15 Revision 5** 

**October 2012** Method 8082A: **Polychlorinated Biphenyls (PCBs) by Gas Chromatogr aphy** 

Method 8085: **Compound-independent Elemental Quantitation of Pes ticides** 

**by Gas Chromatography with Atomic Emission Detectio n**  **(GC/AED)**

Method 8091: **Nitroaromatics and Cyclic Ketones by Gas Chromatog raphy** 

Method 8095: **Explosives by Gas Chromatography**

Method 8100: **Polynuclear Aromatic Hydrocarbons**

Method 8111: **Haloethers by Gas Chromatography**

Method 8121: **Chlorinated Hydrocarbons by Gas Chromatography:**

**Capillary Column Technique**

Method 8131: **Aniline and Selected Derivatives by Gas Chromatogr aphy** 

Method 8141B: **Organophosphorus Compounds by Gas Chromatography**

Method 8151A: **Chlorinated Herbicides by GC Using Methylation or**

**Pentafluorobenzylation Derivatization**

**4.3.2 Gas chromatographic/mass spectrometric method s** 

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for**  **guidance on the allowed flexibility in the choice o f apparatus, reagents, and supplies. In**  **addition, unless specified in a regulation, the use of SW-846 methods is not mandatory in**  **response to Federal testing requirements. The infor mation contained in each procedure is**  **provided by EPA as guidance to be used by the analy st and the regulated community in**  **making judgments necessary to meet the data quality objectives or needs for the intended** 

**use of the data.**

**The following methods are included in this section:**

Method 8260B: **Volatile Organic Compounds by Gas Chromatography/M ass** 

**Spectrometry (GC/MS)**

Method 8261: **Volatile Organic Compounds by Vacuum Distillation in** 

**Combination with Gas Chromatography/Mass Spectromet ry**  **(VD/GC/MS)**

Method 8270D: **Semivolatile Organic Compounds by Gas**

**Chromatography/Mass Spectrometry (GC/MS)**

Method 8275A: **Semivolatile Organic Compounds (PAHs and PCBs) in**

**Soils/Sludges and Solid Wastes Using Thermal Extrac tion/Gas**  **Chromatography/Mass Spectrometry (TE/GC/MS)**

Method 8280B: **Polychlorinated Dibenzo-** p **-Dioxins (PCDDs) and**

**Polychlorinated Dibenzofurans (PCDFs) by High-Resol ution**  **Gas Chromatography/Low Resolution Mass Spectrometry (HRGC/LRMS)** 

Method 8290A: **Polychlorinated Dibenzo-** p **-dioxins (PCDDs) and**

**Polychlorinated Dibenzofurans (PCDFs) by High-Resol ution**  **Gas Chromatography/High-Resolution Mass Spectrometr y**  **(HRGC/HRMS)** Appendix A: **Procedures for the Collection, Handling, SW-846 Update V FOUR - 16 Revision 5** 

**October 2012 Analysis and Reporting of Wipe Tests Performed with**  **in the Laboratory** 

**4.3.3 High performance liquid chromatographic metho ds** 

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for**  **guidance on the allowed flexibility in the choice o f apparatus, reagents, and supplies. In**  **addition, unless specified in a regulation, the use of SW-846 methods is not mandatory in**  **response to Federal testing requirements. The infor mation contained in each procedure is**  **provided by EPA as guidance to be used by the analy st and the regulated community in**  **making judgments necessary to meet the data quality objectives or needs for the intended** 

**use of the data.**

**The following methods are included in this section:**

Method 8310: **Polynuclear Aromatic Hydrocarbons**

Method 8315A: **Determination of Carbonyl Compounds by High Perfor mance** 

**Liquid Chromatography (HPLC)** Appendix A: **Re-crystallization of 2,4-Dinitrophenylhydrazine (DNPH)** 

Method 8316: **Acrylamide, Acrylonitrile and Acrolein by High Per formance**  **Liquid Chromatography (HPLC)**

Method 8318A: N

**-Methylcarbamates by High Performance Liquid Chromatography (HPLC)** 

Method 8321B: **Solvent-Extractable Nonvolatile Compounds by High**

**Performance Liquid Chromatography/Thermospray/Mass Spectrometry (HPLC/TS/MS) or Ultraviolet (UV) Detec**  **tion**

Method 8325: **Solvent Extractable Nonvolatile Compounds by High**

**Performance Liquid Chromatography/Particle Beam/Mas s**  **Spectrometry (HPLC/PB/MS)**

Method 8330A: **Nitroaromatics and Nitramines by High Performance Liquid** 

**Chromatography (HPLC)**

Method 8331: **Tetrazene by Reverse Phase High Performance Liquid**

**Chromatography (HPLC)**

Method 8332: **Nitroglycerine by High Performance Liquid Chromato graphy** 

**4.3.4 Infrared methods**

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for**  **guidance on the allowed flexibility in the choice o f apparatus, reagents, and supplies. In**  **addition, unless specified in a regulation, the use of SW-846 methods is not mandatory in**  **response to Federal testing requirements. The infor mation contained in each procedure is**  **provided by EPA as guidance to be used by the analy st and the regulated community in**  **making judgments necessary to meet the data quality objectives or needs for the intended** 

**use of the data. SW-846 Update V FOUR - 17 Revision 5** 

**October 2012 The following methods are included in this section:** 

Method 8410: **Gas Chromatography/Fourier Transform Infrared (GC/ FT-IR)** 

**Spectrometry for Semivolatile Organics: Capillary C olumn** 

Method 8430: **Analysis of Bis(2-chloroethyl) Ether and Hydrolysi s Products by** 

**Direct Aqueous Injection GC/FT-IR**

Method 8440: **Total Recoverable Petroleum Hydrocarbons by Infrar ed** 

**Spectrophotometry**

**4.3.5 Miscellaneous spectrometric methods**

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for**  **guidance on the allowed flexibility in the choice o f apparatus, reagents, and supplies. In**  **addition, unless specified in a regulation, the use of SW-846 methods is not mandatory in**  **response to Federal testing requirements. The infor mation contained in each procedure is**  **provided by EPA as guidance to be used by the analy st and the regulated community in**  **making judgments necessary to meet the data quality objectives or needs for the intended** 

**use of the data.**

**The following method is included in this section:**

Method 8520: **Continuous Measurement of Formaldehyde in Ambient Air** 

**4.4 IMMUNOASSAY METHODS**

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for guidance**  **on the allowed flexibility in the choice of apparat us, reagents, and supplies. In addition, unless**  **specified in a regulation, the use of SW-846 method s is not mandatory in response to Federal**  **testing requirements. The information contained in each procedure is provided by EPA as**  **guidance to be used by the analyst and the regulate d community in making judgments necessary**  **to meet the data quality objectives or needs for th e intended use of the data.** 

**The following methods are included in this section:**

Method 4000: **Immunoassay**

Method 4010A: **Screening for Pentachlorophenol by Immunoassay**

Method 4015: **Screening for 2,4-Dichlorophenoxyacetic Acid by**

**Immunoassay**

Method 4020: **Screening for Polychlorinated Biphenyls by Immunoa ssay**  Method 4025: **Screening for Polychlorinated Dibenzodioxins and**

**Polychlorinated Dibenzofurans (PCDD/Fs) by Immunoas say**  Method 4030: **Soil Screening for Petroleum Hydrocarbons by Immun oassay**  Method 4035: **Soil Screening for Polynuclear Aromatic Hydrocarbo ns by** 

**Immunoassay**

Method 4040: **Soil Screening for Toxaphene by Immunoassay**

Method 4041: **Soil Screening for Chlordane by Immunoassay SW-846 Update V FOUR - 18 Revision 5** 

**October 2012** Method 4042: **Soil Screening for DDT by Immunoassay**

Method 4050: **TNT Explosives in Soil by Immunoassay**

Method 4051: **Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in S oil by** 

**Immunoassay**

Method 4425: **Screening Extracts of Environmental Samples for Pl anar** 

**Organic Compounds (PAHs, PCBs, PCDDs/PCDFs) by a Reporter Gene on a Human Cell Line** 

Method 4430: **Screening For Polychlorinated Dibenzo-p-Dioxins An d Furans** 

**(PCDD/Fs) By Aryl Hydrocarbon-Receptor PCR Assay**

Method 4435: **Method For Toxic Equivalents (TEQS) Determinations For** 

**Dioxin-Like Chemical Activity with the CALUX** 

### ® **Bioassay**

Method 4670: **Triazine Herbicides as Atrazine in Water by Quantit ative** 

**Immunoassay**

**4.5 MISCELLANEOUS SCREENING METHODS**

**Prior to employing the methods in this chapter, ana lysts are advised to consult the** 

**disclaimer statement at the front of this manual an d the information in Chapter Two for guidance**  **on the allowed flexibility in the choice of apparat us, reagents, and supplies. In addition, unless**  **specified in a regulation, the use of SW-846 method s is not mandatory in response to Federal**  **testing requirements. The information contained in each procedure is provided by EPA as**  **guidance to be used by the analyst and the regulate d community in making judgments necessary**  **to meet the data quality objectives or needs for th e intended use of the data.** 

**The following methods are included in this section:**

Method 3815: **Screening Solid Samples for Volatile Organics**

Method 3820: **Hexadecane Extraction and Screening of Purgeable O rganics** 

Method 8510: **Colorimetric Screening Procedure for RDX and HMX i n Soil** 

Method 8515: **Colorimetric Screening Method for Trinitrotoluene (TNT) in Soil** 

Method 8535: **Screening Procedure for Total Volatile Organic Hal ides in** 

**Water**

Method 8540: **Pentachlorophenol by UV-Induced Colorimetry**

Method 9074: **Turbidimetric Screening Method for Total Recoverabl e**  **Petroleum Hydrocarbons in Soil**

Method 9078: **Screening Test Method for Polychlorinated Biphenyl s in Soil** 

Method 9079: **Screening Test Method for Polychlorinated Biphenyl s in** 

**Transformer Oil SW-846 Update V FOUR - 19 Revision 5** 

**October 2012 4.6 REFERENCES** 



### 1. A. B. Dindal, R. A. Jenkins, and C. K. Bayne. "S **ummary Report - Evaluation of the Impact of Post-Holding Time Analyte Degradation on**  **Regulatory Decision-Making - VOCs in Water," Oak Ridge National Laboratory. 2001** 

**.**

**2. ASTM Standard D4841, 1988 (2008).**  **Standard Practice for Estimation of Holding Time for Water Samples Containing Organic and Inorganic**  **Constituents. ASTM International,**  **West Conshohocken, PA, 2003, DOI: 10.1520/D4841-88R 08,**  **www.astm.org**



### 3. **J. T. Love, G. C., Deltzer, S. R. Abney, and J. S. Zogorski. “Study Design and Analytical**  **Results Used to Evaluate Stability of Volatile Orga nic Compounds in Water Matrices.”**  **United States Geological Survey Open-File Report 98 -637. 1999.** 



### 4. **M. P. Maskarinec, C. K. Bayne, L. H. Johnson, S. K. Holladay, and R. A. Jenkins.**  **“Stability of Volatile Organics in Environmental Wa ter Samples: Storage and**  **Preservation.” Oak Ridge National Laboratory ORNL/T M-11300. 1989.** 



### 5. **O. R. West, C. K. Bayne, R. L. Siegrist, W. L. Hold en, S. S. Scarborough, and D. W.**  **Bottrell. “Stability of VOCs in Water samples Durin g Pre-analytical Holding. Part 1.**  **Analyses by a Commercial Laboratory.” Oak Ridge Nat ional Laboratory** 

**ORNL/TM-13240/V1. 1996.**

**6. O. R. West, C. K. Bayne, R. L. Siegrist, W. L. H olden, and D. W. Bottrell. “Stability of**  **VOCs in Water samples During Pre-analytical Holding . Part 2. Analyses by an EPA**  **Regional Laboratory.” Oak Ridge National Laboratory ORNL/TM-13240/V2. 1997.** 

**7. C. K. Bayne, D. D. Schmoyer, and R. A. Jenkins. “Practical Reporting Times for**  **Environmental Samples.” Environmental Science and T echnology, 28: 1430-1436.** 

**1994.**

**8. M. P. Maskarinec, C. K. Bayne, R. A. Jenkins, L. H. Johnson, and S. K. Holladay.**  **“Final Report - Stablity of Volatile Organics in En vironmental Soil samples.” Oak Ridge**  **National Laboratory ORNL/TM-12128. 1992.**

**9. Preservation and Holding Times Study for Vinyl C hloride, Styrene in Industrial**  **Wastewater provided by Test America, January 2012.**

**10. Preservation and Holding Times Study for Vinyl Chloride, Styrene in Municipal**  **Wastewater provided by the Hampton Roads Sanitation District in Virginia Beach,**  **Virginia, January 2012.**

**11. ASTM Guide D4547, 1991 (2009). Standard Guide for Sampling Waste and Soils for**  **Volatile Organic Compounds. ASTM International, West Conshohocken, PA, 2003,**  **DOI: 10.1520/D4547-09, www.astm.org** 

**12. U.S. Environmental Protection Agency. “Sample H olding Time Re-evaluation.”** 

**EPA/600/R-05/124. 2005. SW-846 Update V FOUR - 20 Revision 5** 

**October 2012 13. U.S. Environmental Protection Agency. “Performa**  **nce of Hydrochloric Acid and Trisodium Phosphate as Preservatives for Selected O**  **rganic Compounds in Ground Water.” In: A Guide for Assessing Biodegradation a**  **nd Source Identification of Organic Ground Water Contaminants using Compound Sp**  **ecific Isotope Analysis, EPA**

**600/R-08/148. 2008.**

**14. ASTM Standard Practice D6418, 2003 (2009). Standard Practice for Using the**  **Disposable En Core Sample for Sampling and Storing Soil for Volatile Organic**  **Analysis. ASTM International, West Conshohocken, PA, 2003, DO**  **I: 10.1520/D6418-09,**  **www.astm.org**

**15. RCRA Organic Methods Workgroup Meeting Minutes, January 19, 2012.** 

**16. RCRA Organic Methods Workgroup Meeting Minutes, January 26, 2012.** 

**17. RCRA Organic Methods Workgroup Meeting Minutes, February 9, 2012.** 

**18.** 

### U.S. Environmental Protection Agency. “Integrity of **VOA Vial Seals.”**

**EPA/600/R-00/066. 2000. SW-846 Update V FOUR - 21 Revision 5** 

**October 2012 Appendix A:**  **Summary of Updates/Changes in Chapter 4**

**1. The document format was updated to Microsoft Wor d 2007.docx format.**  **2. The Revision number was changed to 5. The date p ublished was updated to October** 

**2012. 3. Various editorial corrections were made througho**  **ut Section 4.1 to 4.5 to improve clarity. 4. Table 4-1 was reformatted and updated by removin**  **g the recommendation to collect a second set of samples without adding an acid preser**  **vative and analyze in a shorter time frame if vinyl chloride and styrene are analytes of**  **concern for aqueous samples.**

**5. Methods 3511 and 3572 were added to Section 4.2. 1. Various Method version letters**  **were updated to the current version. 6. Methods 4025, 4430 and 4435 were added to Sectio**  **n 4.4**

**7. A references section was added as Sec.4.6.**