National Institute for Occupational Safety and Health

“ Calibrate daily with at least five working standards over the range 0.005 to 1 mg/mL PCB. a. Add known amounts of calibration stock solution to n-hexane in 10-mL volumetric flasks and dilute to the mark with n-hexane. b. Analyze the working standards together with samples and blanks (steps 29 and 30) . c. Prepare calibration graph (concentration of each PCB standard vs. the sum of PCB peak areas) . 28. Analyze at least three pooled or spiked serum samples. ”

“ Read the concentration of PCB in the hexane solution (μg/mL) from the calibration graph. 33. Calculate the serum PCB concentration, C (μg/mL) , by dividing the PCB concentration found in the extract, C e, by 5 (5 mL serum yields 1 mL extract) :
GUIDES FOR INTERPRETATION: PCBs are present in the biosphere. Baselt [5] indicates a level 2 to 4 μg/L of plasma is indicative of significant exposure. Finklea [6] reported 57% of individuals tested had levels below 5 μg/L. Most control populations have PCB levels below 20 μg/L serum. What levels present a health hazard is not documented ”

“ Pour a suspension of 3 g silica gel in 50 mL hexane into the column. c. Let the suspension settle and add 5 to 7 g sodium sulfate. 10. Syringes, 10-μL, glass. 11. Graduated cylinder, 25-mL.** 12. Pipet, Pasteur.
Clean all glassware, including that used in sampling as follows: Wash in detergent. Rinse with tap water. Soak in chromic acid. Rinse with, in order, tap water, distilled water, acetone and hexane.
SPECIAL PRECAUTIONS: Samples of blood collected from humans pose a real health risk to laboratory workers who collect and handle these samples. ”