Determination of hexafluoroisopropanol, a sevoflurane urinary metabolite, by 9-fluorenylmethyl chloroformate derivatization.

A reversed-phase HPLC method with fluorescence detection for the quantification of hexafluoroisopropanol (HFIP) in urine is presented. HFIP, a metabolite of the inhalation anesthetic sevoflurane, is excreted mainly in urine as glucuronic acid conjugate. After enzymatic hydrolysis of the glucuronate, primary amino groups of interferent urinary compounds are blocked by reaction with o-phthalic dicarboxaldehyde and 3-mercaptopropionic acid, followed by labeling of HFIP with 9-fluorenylmethyl chloroformate. The derivatization reaction proceeds in a water-acetonitrile (1:1) solution at room temperature with a borate buffer of pH 12.5 as a catalyst. A stable fluorescent derivative of HFIP is formed within 5 min. The HFIP-FMOC derivative is separated by reversed-phase chromatography with isocratic elution on an octadecyl silyl column (33x4.6 mm, 3 microm) and guard column (20x4.0 mm, 40 microm), at 35 degrees C, and detected by fluorescence detection at an excitation wavelength of 265 nm and an emission wavelength of 311 nm. The method detection limit is 40 pg, per 10-microl injection volume, corresponding to 16 microg/l of HFIP in urine. The among-series relative standard deviation is <6% at 200 microg/l (n=6). As a preliminary application, the method was used to detect HFIP concentration in the urine of two volunteers exposed for 3 h to an airborne concentration of sevoflurane in the order of 2 ppm.

Inaccuracy quality control in the monitoring of trace metal concentrations in biological fluids.

Quality assurance in trace element analysis requires continual surveillance of the accuracy and precision of results. A review of difficulties encountered in performing quality control programs of trace metal analysis in biological fluids is presented. Examples to clarify the inadequacy of available biological reference materials for quality control in biological monitoring of environmental and occupational low level exposure to metals are reported.

[Application of high-pressure liquid chromatography in the analysis of urinary metabolites of aromatic solvents]. / Applicazioni della cromatografia liquida ad alte prestazioni nell'analisi dei metaboliti urinari dei solventi aromatici.

The introduction of HPLC methods in industrial toxicology represents a valuable tool for the routine monitoring of workers occupationally exposed to aromatic solvents. The HPLC method described here permits the simultaneous determination of metabolites of ethylbenzene, styrene, toluene, xylene isomers, benzene, phenol and cresol isomers in diluted urine samples. Pretreatment of urine samples with steam distillation is necessary only for determination of phenol and cresols because of their low concentrations. A comparison between a GLC and the HPLC procedure for mandelic and phenylglyoxylic acids confirmed the satisfactory performance of the HPLC method.