The determination of parts per billion concentrations of hexamethylphosphoramide and its metabolite, pentamethylphosphoramide, in urine.
Hexamethylphosphoramide (HMPA) possesses unique solvent properties as a solvent in organic and organometallic reactions. Its acute toxicity is low to moderate. Its chronic toxicity is more severe in that inhalation exposure to HMPA vapor concentrations as low as 50 ppb for 12 months produced squamous cell carcinoma of the nasal cavity in laboratory rats. A simple and rapid technique for measuring in urine HMPA and its principal metabolite, pentamethylphosphoramide (PMPA) is described. Twenty mL of 50% (w/v) sodium hydroxide-water solution is added to a 50-mL urine specimen. HMPA and its demethylated metabolite, PMPA, then are extracted from the urine specimen with 5 mL of chloroform. For the nominal concentration range of 10 to 1000 ng/mL, HMPA and PMPA extraction from urine into chloroform averaged 88.0% and 80.2% respectively. The HMPA and PMPA in the extract are assessed by gas chromatography, using a phosphorous flame photometric detector, and quantified by an external standard calibration technique. The limit of detection for HMPA and PMPA in urine is 2 ng/mL. The total analysis time is less than 20 min. The method was validated by analyzing spiked urine samples prepared by another laboratory. Linear regression correlation coefficients greater than 0.99 were obtained for HMPA and PMPA for the 10 to 192 ng/mL concentration range.
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E.I. Du Pont de Nemours & Company, Inc., Wilmington, DE 19898.
D002849:Chromatography, Gas; D006492:Hempa / Q000378:metabolism / Q000652:urine*; D006801:Humans; D007202:Indicators and Reagents; D009943:Organophosphorus Compounds / Q000652:urine*; D012972:Sodium Hydroxide / Q000494:pharmacology
D007202:Indicators and Reagents; D009943:Organophosphorus Compounds; D012972:Sodium Hydroxide; D006492:Hempa