title: Use of a holder-vacuum tube device to save on-site hands in preparing urine samples for head-space gas-chromatography, and its application to determine the time allowance for sample sealing.
abstract: To facilitate urine sample preparation prior to head-space gas-chromatographic (HS-GC) analysis. Urine samples containing one of the five solvents (acetone, methanol, methyl ethyl ketone, methyl isobutyl ketone and toluene) at the levels of biological exposure limits were aspirated into a vacuum tube via holder, a device commercially available for venous blood collection (the vacuum tube method). The urine sample, 5 ml, was quantitatively transferred to a 20-ml head-space vial prior to HS-GC analysis. The loaded tubes were stored at +4 ℃ in dark for up to 3 d. The vacuum tube method facilitated on-site procedures of urine sample preparation for HS-GC with no significant loss of solvents in the sample and no need of skilled hands, whereas on-site sample preparation time was significantly reduced. Furthermore, no loss of solvents was detected during the 3-d storage, irrespective of hydrophilic (acetone) or lipophilic solvent (toluene). In a pilot application, high performance of the vacuum tube method in sealing a sample in an air-tight space succeeded to confirm that no solvent will be lost when sealing is completed within 5 min after urine voiding, and that the allowance time is as long as 30 min in case of toluene in urine. The use of the holder-vacuum tube device not only saves hands for transfer of the sample to air-tight space, but facilitates sample storage prior to HS-GC analysis.
authors.affiliation: Osaka Occupational Health Service Center, Japan Industrial Health Safety and Health Association, Osaka 550-0001, Japan. tkawai@jisha.or.jp
authors.forename: Toshio
authors.initials: T
authors.lastname: Kawai
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Sumino
authors.forename: Fumiko
authors.initials: F
authors.lastname: Ohashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ikeda
mesh_terms: D000096:Acetone / Q000652:urine; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods; D006801:Humans; D000432:Methanol / Q000652:urine; D008742:Methyl n-Butyl Ketone / Q000652:urine; D012034:Refrigeration; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014050:Toluene / Q000652:urine; D014556:Urine; D014618:Vacuum
chemical_list: D000096:Acetone; D014050:Toluene; D008742:Methyl n-Butyl Ketone; C005458:methyl isobutyl ketone; D000432:Methanol