National Institute for Occupational Safety and Health

“ The highest result for the RSD of the 9 samples fortified at 1 ng/L BMA was 29%. While the accuracy numbers meet standard criteria, the precision values at the lower concentrations do not [7] . The use of a urine substitute for QC samples is not recommended for this method. The third recovery study used urine specimens from twelve non-exposed volunteers; six were smokers and six were non-smokers. Most participants’ specimens had base levels for both BMA and PMA as are shown in Table 4. Again, reasonable accuracy and precision were demonstrated for a 6 ng/mL equivalent level spike ”

“ It is important to ascertain smoking status and other non-occupational exposures that may cause elevated levels of these metabolites. Linearity. All calibration curves used during the development of this method were linear and had correlation coefficients of 0.99 and greater. The concentration range was equivalent to 0.5 to 50 ng/mL BMA and PMA for the extraction of 4.0 mL urine. Calibration curves were run at the beginning and end of all sample batch runs ”

“ Add 0.5 mL of the 30 ng/mL deuterated BMA/PMA internal standard solution. 8.
Solid-Phase Extraction NOTE: All SPE steps are performed using the vacuum manifold apparatus. The flow rate should not exceed 1 mL/min. The SPE cartridges should not be allowed to go to dryness until the end of Step 8d. Refer to manufacturers’ recommendations for use of specific SPE cartridges. a. Pre-wash the C18 SPE cartridge with 2 mL of acetone. b. Equilibrate the SPE cartridge with 2 mL of HPLC grade water. c. Load the 5-mL urine mixture and draw the sample through the cartridge. ”

“ Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area [2013] . List of MAK and BAT values 2013; Maximum Concentrations and Biological Tolerance Values at the Workplace. ”