Determination of mandelic and phenylglyoxylic acids in rat urine by high-performance liquid chromatography and by isotachophoresis.
Sollenberg-J; Smallwood-AW; Lowry-AW
J Chromatogr, Biomed Appl 1985 Jan; 343:175-178
High performance liquid chromatography (HPLC) and isotachophoresis (ITP) were evaluated for use in the analysis of mandelic-acid (456597) (MA) and phenylglyoxylic-acid (611734) (PGA) in rat urine as a part of a biotransformation study of ethylbenzene (100414) (EB). Oral doses (350mg/kg body weight) of EB in corn-oil were given to four male Sprague-Dawley-rats weighing 190 to 210 grams. Urine samples were collected as voided, diluted with distilled water, and filtered with 0.45 micron filters. A 500 microliter sample was taken and extracted twice with 5 milliliters of diethyl- ether, then evaporated under nitrogen. The residue was then dissolved in 200 microliters distilled water, and analyzed by both ITP and HPLC. Comparison of HPLC and ITP for MA with 59 samples of rat urine yielded a correlation coefficient of 0.982 indicating that the two methods gave similar results. With PGA, the correlation coefficient was 0.979. The estimated lower limits of quantitation for MA were 0.01 micromole/liter (micromol/l) and 0.04micromol/l with HPLC and ITP, respectively. The lower limits of quantitation for PGA were 0.01micromol/l with HPLC and 0.02micromol/l with ITP. According to a paired t-test there was no significant difference between the results of the two methods. HPLC was observed to be more sensitive, but ITP was more rapid.
Analytical-methods; Chromatographic-analysis; Quantitative-analysis; Urinalysis; In-vivo-studies; Laboratory-animals; Organic-acids; Metabolic-study
456-59-7; 611-73-4; 100-41-4
Journal of Chromatography, Biomedical Applications