STANDARD OPERATING PROCEDURE

LABORATORY PREPARATION, FIELD COLLECTION, AND LABORATORY PROCESSING OF SOILS FOR TOC AND VOC HEADSPACE

Prepared by:

Seth Lyman, PhDBingham Entrepreneurship and Energy Research CenterUtah State University320 N Aggie BlvdVernal, UT 84078

Certified by:

Certification Date:

DOCUMENT NUMBER: BRC_160505_AREVISION: ORIGINAL RELEASEDATE: 5 MAY 2016

320 North Aggie Blvd Vernal, UT 84078 rd.usu.edu ubair.usu.edu

1. Contents

1. Contents..............................................................................................................................................2

2. Preparation of Sample Collection Materials in the Laboratory............................................................3

2.1. Vials for VOC Headspace.............................................................................................................3

2.2. Vials for dry soil weight determination........................................................................................3

2.3. Bags for TOC................................................................................................................................3

3. Things to Take With You to The Field..................................................................................................4

4. What To Do In the Field.......................................................................................................................4

4.1. Collecting Samples for Total Organic Carbon..............................................................................4

4.2. Collecting Samples for VOC Headspace.......................................................................................5

5. Sample Processing to Prepare Samples for Analysis............................................................................6

5.1. VOC Headspace Vials...................................................................................................................6

5.2. Vials for Dry Weight Determination............................................................................................6

5.3. Samples for TOC..........................................................................................................................7

6. Safety...................................................................................................................................................7

7. Hazardous Waste Disposal..................................................................................................................7

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2. Preparation of Sample Collection Materials in the Laboratory

2.1. Vials for VOC Headspace

Soil samples for VOC headspace analysis are collected in 20 mL screw-top headspace vials. These vials are specifically made for the PAL autosampler.

1. Prepare four vials each for the first two soil samples you intend to collect, and two vials each for all remaining samples. This will give you one spare vial for every sample you will collect. The four vials for the first two soil samples will allow you do run a duplicate sample and a matrix spike (i.e., injection of calibration standards into an existing sample). It is a good idea to prepare enough vials for 1-2 samples more than what you are planning to collect. Also, prepare two extra vials as field blanks.

2. Use a repeating pipette to fill each vial with 10 mL of a solution of 8 g NaCl in 100 mL total volume of water. Do the following to prepare the salt solution:

a. Wash a beaker or other glass container with Liquinox soap. Scrub the container all over with the soap.

b. Rinse the container with lots and lots of ultrapure (18.2 megaohms per centimeter) water.

c. Add 8 g NaCl to the container (the recipe can be doubled or tripled as needed)d. Add ultrapure water until the container contains 100 mL total volume of solution.

3. Screw the top on the vial4. Weigh the vial. Record the weight to the nearest 0.001 grams on the vial.5. Place each set of two or four vials in a Ziploc bag and put it in the refrigerator until you are ready

to take it to the field. When you do take it to the field, it should be on ice except when being filled with soil.

2.2. Vials for dry soil weight determination

Soil samples are collected for dry weight determination along with VOC headspace samples.

1. Prepare one vial for dry weight determination for each of the soil samples you will collect. It is a good idea to prepare enough vials for 1-2 samples more than what you are planning to collect.

2. You may use 20 mL headspace vials, or any vial that is between 10 and 40 mL, is glass, and has a screw-top lid.

3. Attach the lid to the vial and weigh the empty vial. If you need to affix a tape label to the vial, do so before weighing it. Record the weight to the nearest 0.001 grams on the vial.

4. Place the vials in a Ziploc bag and store them with the VOC heaspace vials.

2.3. Bags for TOC

Obtain a quart-sized Ziploc freezer bag (or another zipper bag of similar thickness) for each sample you intend to collect. It is a good idea to prepare more bags than you think you will need.

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3. Things to Take With You to The Field

1. Take four 20 mL screw-top headspace vials for two of the samples you intend to collect, and take two 20 mL screw-top headspace vials for each other sample you intend to collect. Also, bring two extra 20 mL headspace vials as field blanks. Each 20 mL screw-top headspace vial should be:

a. Filled with 10 mL of a solution of 8 g NaCl in 100 mL total volume (including NaCl) of water.

b. Weighed, and the weight of the vial (including saline solution and cap) should be written on the vial with a permanent marker. Don’t add any label tape or other label after weighing.

2. Take one additional glass vial for each sample you intend to collect. It can be a 20 mL headspace vial or some other vial that is at least 10 mL. These will be for samples that will be dried for dry soil weight. Each of these vials need to be weighed, and the weight of the vial (including saline solution and cap) should be written on the vial with a permanent marker. Don’t add any label tape or other label after weighing.

3. Take quart-sized ziplock freezer bags for TOC analysis.4. Take some kind of 1 mL container or tube. It is best to have a separate 1mL volume tube for

each sample you intend to collect. It is also best to bring something clean that you can use to push the soil out of the tube after you pack it in.

5. The vials with saline solution should be kept on ice at all times. So take a cooler full of ice and keep the vials in it.

6. Take gloves to keep the samples clean from your dirty hands.7. Take a shovel for collecting the TOC samples.8. Take this SOP.

4. What To Do In the Field

If you are collecting samples in concert with a flux chamber analysis, collect the samples after your flux chamber sample is complete. Collect soil samples from right where the chamber was sitting.

Always wear clean, new disposable gloves when collecting soil samples. If you gloves become dirty, replace them.

4.1. Collecting Samples for Total Organic Carbon

1. Use the shovel to scoop a quart Ziploc freezer bag about half full of soil. Scoop from the top 2-3 inches of soil

2. Put another freezer bag over that bag. 3. Label the bag with whatever sample name you choose.4. Write the sample name, along with notes about the sample collection, the time and place of

collection, how it relates to flux chamber sampling, etc., in your log book. 5. If the soil is particularly rich in organics, wipe the shovel off or wash it between samples.

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4.2. Collecting Samples for VOC Headspace

4.2.1. Regular Samples

1. Press soil from the sample location into a tube with 1 mL internal volume. If you need to use a tool to break up the soil before you do this, it is okay. Make sure it is something that isn’t contaminated with oil or other hydrocarbon products. If you are collecting samples in concert with flux chamber samples, collect your soil sample from the top 1-2 inches of soil.

2. Open a 20 mL headspace vial that contains 10 mL saline solution.3. Push the soil out of the 1 mL volume tube and into the headspace vial. Use a clean pipette tip or

something to push the soil out. 4. Close the headspace vial lid.5. Label the vial and put it in a ziplock freezer bag. 6. Collect either 1 or 3 additional soil samples in the same way from the same location. For every

sampling event, four vials should be collected for each sampling location for at least two of the samples, and two vials should be collected for all other sampling locations. Use the same 1 mL volume tube and the same pipette tip for the 2 or 4 replicate soil samples you collect at a single sampling location. Use new tubes and pipettes for each sampling location.

7. After a freezer bag contains the 2 or 4 vials for that sample, seal it and put it in the cooler on ice.8. Write the sample name, along with notes about the sample collection, the time and place of

collection, how it relates to flux chamber sampling, etc., in your log book.

4.2.2. Dry Weight Samples

Along with the regular samples, you need to collect additional samples to be analyzed for dry soil weight. The dry weight vial should be empty and dry on the inside, and it should have been pre-weighed, and the weight should be written on the vial.

1. For each location at which you collect 2 or 4 vials of soil by the method in Section 3.2.1, you should use the same 1 mL volume tube and pipette tip to collect a dry weight sample.

2. Collect soil into the dry weight sample vial in the same way as outlined in Section 3.2.1, except that you should collect FOUR 1 mL volumes of soil into one dry weight sample.

3. Label the dry weight sample and put it in a Ziploc bag.4. Put the bag with the sample in the cooler on ice.5. Write the sample name, along with notes about the sample collection, the time and place of

collection, how it relates to flux chamber sampling, etc., in your log book.

4.2.3. Field Blanks

For field blanks, open the vial cap, then immediately close it, label it, and put it in a Ziploc bag. You should have two field blank vials per sampling event. After you have opened and closed the vial caps of the two field blanks and put them in a Ziploc bag, close the bag and put it in the cooler on ice. Write the field blank sample name and collection time in the logbook.

4.2.4. After Returning from the Field

When you return from the field, put all the samples you have collected in the refrigerator.

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5. Sample Processing to Prepare Samples for Analysis

5.1. VOC Headspace Vials

5.1.1. Sample Weighing

Weigh all filled soil VOC headspace vials and record the initial weight from the vial, the final weight, and the difference between the two in your lab notebook, along with the sample name and any other pertinent information about the sample.

Record all weights to the nearest 0.001 grams. Weigh field blanks the same as you weigh other samples.

5.1.2. Sample Holding Time

All VOC headspace samples must be analyzed as soon as possible after collection. The maximum time between collection and analysis is 14 days, but they should be analyzed sooner than that if possible.

5.1.3. Sample Analysis

Soil VOC headspace samples should be analyzed in the same way as water VOC headspace samples. Matrix spikes, duplicates, or any other QC samples should be prepared and analyzed in the same way as water VOC headspace samples

5.2. Vials for Dry Weight Determination

After vials for dry weight determination are returned from the field, they are weighed, dried, and then weighed again, in the following manner:

1. Weigh all filled vials for dry weight determination as soon as you can after they return from the field and record the initial weight from the vial, the final weight, and the difference between the two in your lab notebook, along with the sample name and any other pertinent information about the sample.

Record all weights to the nearest 0.001 grams. Note that each vial for dry weight determination should contain FOUR 1 mL volumes of

soil, so the weight of the soil in the vial should be four times greater than the weight of each VOC headspace soil sample.

2. Remove the caps from the vials. As you do this, mark the caps or otherwise make sure you know with certainty which cap belongs to which vial. Place the caps in a plastic bag or somewhere that they won’t become dirty or collect dust.

3. Place the cap-less vials in a drying oven, and heat the oven to 105-110 degrees C.4. After 48 hours, cool the oven, remove the vials from the oven and re-attach their caps (making

sure to return the proper cap to its vial).5. Weigh each vial and record the weights (to the nearest 0.001 grams) in your lab notebook, along

with the time period and dates of heating and weighing.

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6. Return the vials to the oven, heat them for at least another 24 hours (though longer is no problem), weigh them again, and record the weights in your lab notebook, following the previous steps.

If the weight or any vial is greater than or equal to the weight you obtained before ± 0.005 grams, follow the previous steps to heat the vial or vials again, weigh them again, and record the weights. Do this until each vial receives two consecutive weighings wherein the second weighing is greater than or equal to the weight you obtained before ± 0.005 grams.

7. The final weight (with the vial weight subtracted) divided by four is the dry weight of the corresponding VOC headspace sample.

8. The percent soil moisture can be calculated as the difference between the initial weight (minus the vial weight) and the final, dried weight (minus the vial weight), divided by the final, dried weight (minus the vial weight) and then multiplied by 100.

5.3. Samples for TOC

Process and analyze soil TOC samples according to the SOP for TOC analysis.

6. Safety

Some samples collected may contain hazardous levels of organic compounds like benzene, toluene, etc. Always wear disposable nitrile gloves when handling soils or sample vials. This will protect your skin from hazardous chemicals. Do not reuse disposable gloves. If you feel the environment you are in is unsafe, leave immediately.

When drying samples in the oven, make sure to cool the oven before you handle the samples.

7. Hazardous Waste Disposal

Extra NaCl solution can be poured down the drain, as long as nothing has been added to the solution but water and NaCl.

Dry weight soil samples from uncontaminated locations can be thrown away after use. Dry weight samples from any oil and gas-related facility or any location with known contamination, as well as all VOC headspace soil solutions regardless or origin, should be disposed of in a hazardous waste container, and the container should be given to USU’s EH&S department when full. Hazardous waste containers can be obtained from Kevin Woodward, and Kevin can coordinate with EH&S for retrieval of the containers.

Empty glass vials should be disposed of in containers provided for glassware disposal.

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