EQUIPMENT

1. Alpkem EnviroFlow Solution 3000 autoanalyzer, equipped with a chloride cartridge.
2. Random access autosampler.

REAGENTS

Ferric Nitrate	Fe(NO3)9H2O
Mercuric Thiocyanate	Hg(SCN)2
Methanol	CH3OH
Nitric Acid	HNO3
Thioacetamide	CH3SNH2
Calcium Nitrate	Ca(NO3)24H2O
Activated Charcoal
Brij-35, 30% w/v

STANDARDS

1. Stock solution, 1000 ppm Chloride:
   1. Use a certified, NIST traceable standard.
2. Stock solution, 100 ppm Chloride:
   1. Pipet 10 mL of 1000 ppm chloride standard into a 100 mL volumetric flask.
   2. Dilute to volume with deionized water and mix well.
3. Instrument Calibration Standards:
   1. Pipet the designated aliquots of 100 ppm chloride stock solution into 100 mL volumetric flasks. Dilute to volume with deionized water and mix well.

Standard #	Stock Solution mL	Final Concentration ppm	Instrument Readout lbs/acre
CAL 1	20	20	160
CAL 2	10	10	80
CAL 3	5	5	40
CAL 4	3	3	24
CAL 5	1	1	8

COLOR DEVELOPING SOLUTIONS

1. Stock ferric nitrate solution:
   1. Weigh 202 g ferric nitrate into a 1 liter volumetric flask containing 500 mL deionized water.
   2. Add 31.5 mL of nitric acid.
   3. Dissolve, dilute to volume with deionized water, and mix well.
   4. Filter, using a 45 micron filter under vacuum.
2. Stock mercuric thiocyanate solution:
   1. Using a FUME HOOD, weigh 4.17 g mercuric thiocyanate into a 1 liter volumetric flask containing 500 mL methanol.
   2. Dissolve, dilute to volume with methanol, and mix well.
   3. Filter, using a 45 micron filter under vacuum.
3. Working chloride color solution:
   1. Pipet 30 mL of stock ferric nitrate solution into a 200 mL volumetric flask containing 100 mL of deionized water.
   2. Pipet 30 mL of mercuric thiocyanate solution into the 200 mL volumetric flask.
   3. Add 1 mL of Brij-35.
   4. Dilute to volume with deionized water and mix well.

WASTE DISPOSAL SOLUTION

1. Thioacetamide 13% solution.
   1. Weigh 13 g thioacetamide into a 100 mL flask containing 75 mL of deionized water.
   2. Dilute to volume with deionized water and mix well.

EXTRACTING SOLUTION

0.01M Calcium Nitrate: Weigh 2.36g calcium nitrate into a 1 liter volumetric flask. Dissolve, dilute to volume with deionized water and mix well.

EXTRACTION

1. Scoop 5 mL soil into a 40 mL cylindrical bottle.
2. Add 20 mL extracting solution.
3. Shake on a shaker box at high speed (250 oscillations per minute) for 15 minutes.
4. Filter using Whatman #1 paper.

PROCEDURE

1. Place reagent lines into their designated container.
2. Engage the pump platens and turn on the pump. Allow the pump to run for 10 minutes before beginning sample analysis.
3. Place the instrument calibration standards, quality control standard, and deionized water blank on the auto sampler tray in the following order.

   Tray Position	Sample ID
   1	CAL 1
   2	CAL 2
   3	CAL 3
   4	CAL 4
   5	CAL 5
   6	QC SAMPLE
   7	BLANK

4. Beginning with position #8, pour up the sample extracts.
5. Select CLSOIL from the sample table menu.
6. Construct a sample table as follows:

   Cup Position	Name	Type
   1	SYNC
   5
   7	BLANK	BLNK
   1	CAL 1	C
   2	CAL 2	C
   3	CAL 3	C
   4	CAL 4	C
   5	CAL 5	C
   3	CCV 1	CCV
   6	QC SAMPLE	U
   8	SAMPLE ID	U

7. Use the letter U to denote sample extracts in the type column.
8. Analyze a CCV 1 check (cup position #3) after each 10 samples and after the last sample. Depending on the number if samples, it may be necessary to refill cup #3 during the run.
9. Run a baseline check after each CCV 1 sample.
10. Select CLSOIL from the collect data menu.
11. At the operator prompt, enter the number range for the set and begin the analysis.
12. When the set is completed a full report will be printed.
13. Print out the calibration curve, curve statistics, and sample graph separately.
14. Label the calibration curve and sample graph with the date, compound analyzed, and number range of the samples analyzed in the set.

QUALITY CONTROL

1. The CCV (continuing calibration verification) values must be within 10% of the known values.
2. Values obtained on the quality control sample must agree within limits established by the originating organization.

WASTE DISPOSAL

1. Collect the waste produced by the instrument in a 2 liter plastic bottle.
2. Using a FUME HOOD, Add 20 mL of 13% thioacetamide solution per liter of chloride waste.
3. Mix the solution well and allow to stand under the hood for 24 hours. The container may be capped. A precipitate of mercuric sulfide will form.
4. Filter the solution under the hood through filter paper.
5. Discard the filtrate by flushing it down a drain under the hood.
6. Store the filter paper containing the mercuric oxide in a glass container until it can be disposed of properly.

REFERENCES

1. Method for Chemical Analysis of Water and Wastes, March 1984. EPA-600/4- 79-020, "Chloride", Method 325.2 (Automated Ferricyanide) STORET No. 00940. Environmental Monitoring and Support Laboratory. Office of Research and Development. U.S. Environmental Protection Agency.
2. Zali, D. M., D. Fisher, and M. Q. Garner. Photometric determination of chloride in water. Analytical Chemistry, Vol 28 No 11, 1665-1668.
3. Adriano, D. C. And H. E. Doner. 1982. Bromine, chlorine, and fluorine. In A. L. Page. R. H. Miller and D. R. Keeney (ed.). Methods of Soil Analysis, Part 2, 2nd Ed. Agronomy 9:461-462.