LEAD IN BLOOD AND URINE: METHOD 8003, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3.
4. 5. 6.
7.
8. 9.
EQUIPMENT:
Ammonium pyrrolidine dithiocarbamate (APDC). Stable 6 months. Nonionic surfactant, octyl phenoxy polyethoxy ethanol (Triton X-100 or equivalent). APDC-surfactant solution (APDC-Tx). Dissolve 4 g APDC and 5 mL nonionic surfactant in 40 mL deionized water. Dilute to 200 mL. Check each batch for extraction efficiency. Stable at least two months. Lead nitrate Pb(NO 3)2. Heat 4 h at 120 °C. Cool and store in dessicator. Nitric acid, conc. 70% (w/w), redistilled. Methyl isobutyl ketone (MIBK), water-saturated. Add 100 mL water to 900 mL MIBK. Shake and allow to stand 1 h. Calibration stock solution (1000 µg/mL). Dissolve 1.598 g Pb(NO 3)2 in 2% (w/v) HNO 3 and dilute to 1 L. Store in a polyethylene bottle. Stable 1 year. Air at 40 psi, filtered to remove oil and water. Acetylene, grade recommended by AAS manufacturers.
1. Heparinized, lead-free, "blue-top" blood collection tubes specially prepared for collecting blood samples for blood lead determinations. 2. Vacutainer needles (21-gauge) and holder. 3. Tourniquet and alcohol swabs. 4. Polyethylene bottles (wide mouth), 125-mL. 5. Culture tubes, 16 x 100-mm, with PTFE-lined screw caps.* 6. Centrifuge. 7. Rotary vibration mixer (Vortex) or equivalent. 8. Atomic absorption spectrophotometer (AAS) with lead hollow cathode or electrodeless discharge lamp. 9. Analytical balance. 10. Desiccator. 11. Pipettes, volumetric flasks and other appropriate glass or plasticware for weighing, storing, and dispensing reagents and samples.*
- All glassware and plasticware should be
detergent washed, thoroughly rinsed with tap and deionized water, soaked 4 hrs in 1:1 HNO 3:H 2O and finally thoroughly rinsed with deionized water.
SPECIAL PRECAUTIONS: Samples of blood and urine collected from humans pose a real health risk to laboratory workers who collect and handle these samples. These risks are primarily due to personal contact with infective biological samples and can have serious health consequences, such as infectious hepatitis, and other diseases. There is also some risk from the chemical content of these samples, but this is much less. Those who handle blood and urine specimens should wear protective gloves, and avoid aerosolization of the samples. Mouth pipetting, of course, must be avoided.
SAMPLING: 1. Collect blood samples in heparinized blood collection tubes. Mix immediately. Ship at 4 C and maintain at this temperature prior to analysis. 2. Collect urine at the end of a work shift in 125-mL polyethylene bottles containing 0.2 mL conc. HNO 3; mix. Submit a 25-mL aliquot for lead analysis and another 25-mL aliquot for creatinine determination. SAMPLE PREPARATION: 3. Filter urine samples before analysis. Analyze a 25-mL aliquot for creatinine by standard procedures (e.g., [6]). 4. Place 2.0 mL filtered urine or 2.0 g whole blood in a 16 x 150-mm culture tube. Start a reagent blank at this point with 2 mL deionized water. 5. Add 0.8 mL APDC-surfactant solution. Cap and mix on a rotary vibration mixer for 10 sec. 6. Add 2.00 mL water-saturated MIBK. Cap and rotate on a rotary vibration mixer for 2 min. Centrifuge at 2000 rpm for 10 min. Analyze the Pb-APDC solution in MIBK within 2 h of extraction. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
