Influence of collection and storage materials on glycol ether concentrations in urine and blood

Glycol ethers, such as propylene glycol monomethyl ether (PGME) and propylene glycol monobuthyl ether (PGBE) are solvents found in many professional and domestic products. In biomonitoring studies, the type of materials used to collect, store, and transport these samples can greatly influence the analytical results because materials can adsorb the analyte. Plastic tubes generally have a hydrophobic internal surface that can reduce the concentration of certain chemicals and result in an underestimation of workers' exposures. The aim of this study was to assess whether the storage of PGME and PGBE spiked blood and urine samples led to different PGME and PGBE concentrations in vials made of glass and common plastics (polypropylene (PP), polyethylene (PE) or polystyrene (PS)). Glycol ether concentrations were quantified with headspace gas chromatography equipped with a flame ionization detector. Our results show stable urinary PGME and PGBE concentrations in PP, while up to 15% variations in urinary PGME for PE and PS. For PGME and PGBE in blood, we observed no statistically significant losses in glass, while losses were recorded for all types of plastic tested (PS, PP and PE). We conclude that biomonitoring samples should be collected in glass for blood and PP for urine.