Page:NIOSH Manual of Analytical Methods - 5600.pdf/2

 ORGANOPHOSPHORUS PESTICIDES: METHOD 5600, Issue 1, dated 15 August 1994 - Page 2 of 20 REAGENTS:

EQUIPMENT:

1. Organophosphorus analytes listed in Table 1. and (optional) triphenyl phosphate, analytical standard grade.* 2. Toluene, pesticide analytical grade.* 3. Acetone, ACS reagent grade or better.* 4. Desorbing solution. Add 50 mL acetone to a 500-mL volumetric flask. Dilute to volume with toluene. NOTE: For optional internal standard, add 1 mL of a 5 mg/mL solution of triphenyl phosphate in toluene to 500 mL desorbing solution. 5. Organophosphorus stock solutions, 10 mg/mL. Prepare individual standard stock solutions of each pesticide of interest in 90/10 toluene/acetone (V/V). All pesticides in Table 1 were found to be soluble to at least 10 mg/mL. 6. Spiking solutions for calibration (step 9) and media fortification (steps 10, 11). NOTE: Spiking solutions may contain more than one analyte. a. Spiking solution SS-1: Dilute the volume of stock solution indicated in column F of Table 11 to 10 mL with toluene or 90/10 toluene/acetone. b. Spiking solution SS-2: Dilute 1 mL of SS1 solution with toluene in a 10-mL volumetric flask. 7. Purified gases: Helium, hydrogen, nitrogen, dry air, and oxygen, (if required by detector).

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See Special Precautions 5. 6. 7. 8. 9.

Sampler: glass tube, 11-mm ID x 13-mm OD x 50 mm long, with the outlet end drawn to a 6-mm o.d. x 25 mm long tube. The enlarged part of the tube contains a 270-mg front section of 20/60 mesh XAD-2 sorbent or equivalent held in place by a 9 to 10-mm o.d. quartz fiber filter and polytetrafluoroethylene (PTFE) retaining ring. The front section is separated from the back section of 140 mg XAD-2 sorbent or equivalent with a short plug of polyurethane foam. The back section is held in place by a long plug of polyurethane foam. The tube is available commercially as the OVS-2 sampler. See Figure 2. NOTE: Some OVS-2 tubes contain glass fiber filters, as specified in the OSHA methods (see Table 10). These tubes, however, did not perform as well for the more polar analytes (amides, phosphoramides, and sulfoxides; see Table 9). Low or erratic recoveries for Malathion may be encountered with glass fiber filters. Personal sampling pump, 0.2 to 1 L/min. with flexible connecting tubing, preferably silicon, polyethylene, or PTFE tubing. Vials, 4-mL with PTFE-lined cap; 2-mL GC autosampler vials with PTFE-lined crimp caps. Gas chromatograph, flame photometric detector with 525-nm bandpass filter for phosphorus mode, integrator, and column (Table 6). Syringes, 5-mL and 100-, 50-, and 10-mL for making standard solutions and GC injections. Volumetric flasks, 500-, 10-, and 2-mL. Tweezers. GC vial crimper. Small ultrasonic cleaning bath.

SPECIAL PRECAUTIONS: Organophosphorus compounds are highly toxic. Special care must be SAMPLING: taken to avoid inhalation or skin contact through the wearing of gloves and suitable clothing when 1. Calibrate each personal sampling pump handling pure material [13-17]. with a representative sampler in line. 2. Connect the sampler to personal sampling Toluene is flammable and toxic. Acetone is highly pump with flexible tubing. The sampler flammable. Prepare all samples in a well ventilated should be placed vertically with the large hood. end down, in the worker’s breathing zone in such a manner that it does not impede work performance. [4, 12] 3. Sample at an accurately known flowrate between 0.2 and 1 L/min for a total sample size of 12 to 240 L. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94