RESUMEN
A simple and rapid method is described for the determination of 2-mercaptobenzothiazole and mercaptobenzothiazole disulfide leached from rubber closures into the iodinated contrast medium (sodium iothalamate). The contaminants were extracted with methylene chloride and analyzed by high-performance liquid chromatography using ultraviolet detection at wavelengths of 272 and 328 nm. The structures of the impurities were confirmed unequivocally by mass spectrometry. The minimum detectable level was 1 microgram/100 mL (0.01 ppm). The quantitation of contaminants leached from rubber stoppers provides a means for evaluating possible health risks of the extractables.
Asunto(s)
Cromatografía Líquida de Alta Presión , Contaminación de Medicamentos , Ácido Yotalámico , Tiazoles/análisis , Benzotiazoles , Espectrometría de Masas , GomaRESUMEN
A highly sensitive and specific gas chromatographic-mass spectrometric (GC-MS) assay for the determination of 4,4'-methylenebis(2-chloroaniline) (MBOCA) in urine is reported. It is based on the solvent extraction of the hydrolysed MBOCA conjugates, together with deuterium-labelled benzidine-d8 added as an internal standard, and a two-phase derivatization procedure involving use of pentafluoropropionic anhydride in the presence of ammonia as the phase-transfer catalyst. The reaction is complete within 2 min at room temperature. The pentafluoropropyl derivatives are determined by use of capillary column GC-MS with selected-ion monitoring in the negative ion chemical ionization mode. The lower limit of detection for MBOCA was 1 microgram dm-3 and the calibration graph showed linearity between 10 and 250 micrograms dm-3. The recovery of the analyte added to pooled urine was above 86%. Thirty urine specimens from workers employed in a polyurethane-producing plant were analysed for MBOCA by this method.
Asunto(s)
Metilenobis (cloroanilina)/análisis , Adulto , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Orina/químicaRESUMEN
A sensitive and specific method for determination of 2,5-hexanedione in urine is described. Treatment of the urine specimen directly with n-butylamine yields n-butyl 2,5-dimethyl pyrrole. The latter is extracted into diisopropylether and analyzed by gas chromatography (GC) with flame ionization detection (FID), thermionic specific detection (TSD) (N mode), or mass spectrometric detection (MS). The minimum detectable quantities are 1 mg/L urine when employing FID with a coefficient of variation of less than 6%. Recovery of 2,5-hexanedione added to the urine at the level of 10 mg/L was 78.9%.
Asunto(s)
Hexanos/orina , Hexanonas/orina , Exposición Profesional , Cromatografía de Gases , Humanos , Indicadores y Reactivos , Espectrometría de MasasRESUMEN
The development of an efficient solid sorbent personal sampler with increased convenience for sample collection in workplaces is described. Several solid sorbents were coated with tryptamine, and sampling tubes were prepared with the coated sorbents. These tubes were evaluated for the collection of phenyl isocyanate vapour generated in a commercial test atmosphere generation system that permits the simultaneous collection of up to 12 uniformly loaded samples. Tryptamine-coated XAD-2 resin was shown to be the most efficient solid sorbent for the collection of airborne phenyl isocyanate. The optimum amount of tryptamine needed for coating XAD-2 resin was investigated.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Cianatos/análisis , Triptaminas , Cromatografía Líquida de Alta Presión/métodos , Indicadores y Reactivos , PoliestirenosRESUMEN
A sampling and analytical procedure was developed for the monitoring of airborne 2-methylaziridine (MA). The analyte is collected by drawing air through a solution of 2,4,6-trinitrobenzenesulphonic acid (TNBS). In situ derivatisation of MA with TNBS during sample collection provides stability to the highly reactive analyte and makes it amenable to a sensitive high-performance liquid chromatographic determination with ultraviolet detection. The purified synthetic derivative of MA with TNBS is more suitable as a calibration standard than commercially available MA.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Aziridinas/análisisRESUMEN
Determination of total airborne isocyanates using tryptamine as the derivatising agent was investigated. Tryptamine derivatised isocyanates were analysed by reversed-phase high-performance liquid chromatography (HPLC). The column was equipped with dual detectors of fluorescence emission and amperometric oxidation. The characteristics of fluorescence emission and amperometric oxidation of tryptamine were retained even after its reaction with isocyanates. With this unique behaviour, all tryptamine derivatised isocyanates can be quantified using HPLC by employing a single, pure derivative, such as tryptamine derivatised hexamethylene diisocyanate as the calibration standard. This is especially important for analysing polymeric isocyanates when identical calibration standards are not always available. The applicability of this method for air sampling was evaluated by comparison with the established method of Bagon et al. involving 1-(2-methoxyphenyl)piperazine. Simulation of air sampling was performed in a Test Atmosphere Generation System by the vaporisation of toluene diisocyanate. Satisfactory results were obtained, indicating the applicability of this technique for the determination of total airborne isocyanates.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Cianatos/análisis , Triptaminas , Cromatografía Líquida de Alta Presión , Electroquímica , Indicadores y Reactivos , Espectrometría de FluorescenciaRESUMEN
Carbon disulphide reacts readily with primary alkylamines to yield dithiocarbamates. When injected into the heated injection port of a gas chromatograph, the dithiocarbamates yield the corresponding isothiocyanates. This reaction provides a simple and elegant derivatisation for quantifying, and also confirming the identify of, the primary alkylamines.
Asunto(s)
Aminas/análisis , Monitoreo del Ambiente , Isotiocianatos , Disulfuro de Carbono , Fenómenos Químicos , Química , Cromatografía de Gases , Espectrometría de Masas , Tiocianatos/análisisRESUMEN
Low levels of airborne ethyl 2-cyanoacrylate (ECA) were monitored by drawing air through sampling tubes containing Tenax GC. After desorption with acetone, ECA was quantified by gas chromatography using a thermionic specific detector in the nitrogen mode. Polymerised ECA was shown to yield ECA monomer under the conditions of gas chromatographic analysis.