Blood and urine bioindicators for methanol exposure: effect of chilled and frozen sample storage.
Batterman SA; Xiao H; Franzblau A
Appl Occup Environ Hyg 1996 Jan; 11(1):25-29
This study tested the stability of methanol (67561) in blood and urine samples both refrigerated and frozen in widely used collection and storage containers. Blood and urine samples were prepared at low, medium, and high methanol concentrations for recovery. Stock blood came from the Red Cross and urine from unexposed volunteers. Samples were analyzed at 1, 2, 7, 30, and 210 days after preparation using head space gas chromatography. At medium and high concentrations, the average reproducibilities of methanol in blood and urine were 10.1 and 7.1%, respectively. A decay model that used an intercept of 86 and 93% for blood and urine, respectively, matched the data for frozen blood and chilled urine. Frozen blood at low and medium concentrations were the least reproducible. Urinary methanol showed only small changes over the study period. Methanol recoveries in blood decreased with time and fit a first order model. For chilled and frozen blood, the suggested half lives were 114 and 240 days, respectively. For chilled and frozen urine, the suggested half life was 562 days. Expensive and fragile glass containers did not aid sample preservation. The authors conclude that typical delays in analyzing stored samples for methanol should not degrade results. They recommend refrigerating samples that will be analyzed within a month of collection and freezing samples that will take longer to be analyzed.
NIOSH-Publication; NIOSH-Grant; Grants-other; Blood-analysis; Blood-tests; Urinalysis; Alcohols; Sample-preparation; Sampling-methods; Chromatographic-analysis
Environmental & Indust Health University of Michigan 1420 Washington Heights Ann Arbor, MI 48109-2029
Other Occupational Concerns; Grants-other
Applied Occupational and Environmental Hygiene
University of Michigan at Ann Arbor, Ann Arbor, Michigan