Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 63)

Introduction:Cresol is being used for an antiseptic, disinfectant, maggot-killing agent and cresol soap solution. Since various kinds of more powerful and odorless disinfectants have nowadays become available in practical use, the frequency in the use of cresol seems decreasing. However, the cases of acute poisoning by cresol are still being reported at the present time. The toxic effects of cresol are due to its corrosive actions, resulting in the destruction of cell membranes and coagulation of proteins, and its suppressive action on the central nervous system [1]. There are three isomeric forms of cresol, vis., o-, m- and p-cresols;...
Nội dung trích xuất từ tài liệu:
Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 63) 7.6II.7.6 Cresol by Chiaki FukeIntroductionCresol is being used for an antiseptic, disinfectant, maggot-killing agent and cresol soap solu-tion. Since various kinds of more powerful and odorless disinfectants have nowadays becomeavailable in practical use, the frequency in the use of cresol seems decreasing. However, thecases of acute poisoning by cresol are still being reported at the present time. The toxic effects of cresol are due to its corrosive actions, resulting in the destruction of cellmembranes and coagulation of proteins, and its suppressive action on the central nervous sys-tem [1]. There are three isomeric forms of cresol, vis., o-, m- and p-cresols; the toxicity of eachisomer is somewhat different [2]. The composition ratios of cresol isomers are different accord-ing to cresol-containing products; it, therefore, seems very important to measure the concentra-tions of each isomer of cresol to identify a causative cresol product used in its poisoning case. Cresol, after being absorbed into human bodies, is metabolized into glucuronide- and/orsulfate-conjugated forms and excreted into urine. The half-life of unchanged cresol in blood isas short as about 1.5 h [3]; this means that it becomes undetectable several hours after emer-gency treatments. However, the metabolites (conjugated forms) remain in the body for rela-tively a long time [4–6]; the detection of the conjugated form(s) sometimes becomes necessary. As methods for analysis of cresol, GC [4, 7–9], HPLC [5, 6, 10–14] and capillary electro-phoreisis [15] were reported. In this chapter, procedures for HPLC and GC/MS analysis ofcresol isomers and their conjugates are presented.HPLC analysisReagents and their preparation• A 10-mg aliquot each of o-, m- and p-cresols (Aldrich, Milwaukee, WI, USA and other manufacturers) is dissolved in 10 mL methanol separately (1 mg/mL).• A 10-mg aliquot of 4-ethylphenola (internal standard, IS, Aldrich and other manufacturers) is dissolved in 10 mL methanol (1 mg/mL).• β-Glucuronidase: 10 mg of bovine liver glucuronidase (EC 3.2.1.31, type B-10, 11,000 units/mg solid, Sigma, St. Louis, MO, USA) is dissolved in 1 mL distilled water.• Sulfatase: Aerobacter aerogenes sulfatase (EC 3.1.6.1, 19 units/mL, Sigma).HPLC conditionsInstruments; pump: LC-10A; detectors: SPD-10A and RF-10A (all from Shimadzu Corp., Kyo-to, Japan); column: a Nova-Pak C18 stainless cartridge column (150 × 3.9 mm i.d., particle size© Springer-Verlag Berlin Heidelberg 2005582 Cresol 4 µm, Waters, Milford, MA, USA); guard column: Guard-Pak Nova-Pak C18 (Waters); mobile phaseb: acetonitrile/20 mM potassium dihydrogenphosphate buffer solution (pH 3.0, to be ad- justed with phosphoric acid) (1:4, v/v), containing 20 mM β-cyclodextrin (Sigma and other manufacturers); its flow rate: 1.0 mL/min; detection wavelength: 270 nm for the UV detector; fluorescence detector: Ex 270 nm and Em 305 nm; injection volume: 20 µL. Procedures i. Analysis of unconjugated forms i. A 100-µL volume of a specimenc is mixed with 10 µL of IS solution. ii. A 100-µL volume of acetonitrile is added to the above mixture with stirringd. iii. It is centrifuged at 12,000 g for 10 min. iv. A 20-µL aliquot of the supernatant solution is injected into HPLC. v. Various concentrations (not less than 4 plots) of a cresol isomer plus 10 µL of IS solution are added to blank specimens and processed in the same way to construct a calibration curve. The concentration of a cresol isomer in a test specimen is calculated with the curve. ii. Analysis of the glucuronide-conjugated forms i. A 100-µL volume of a specimenc is mixed with 10 µL of IS solution. ii. A 5-µL volume of 4 M sodium acetate buffer solution (pH 5.0) and 5 µL of β-glucuroni- dase solution are added to the above mixture and incubated at 37 °C for 2 h. iii. After cooling to room temperature, 100 µL acetonitrile is placed in the above mixture with stirring. iv. The following procedure is achieved according to the iii–v steps of the above section. iii. Analysis of the sulfate-conjugated formse i. A 100-µL volume of a specimenc is mixed with 10 µL of the IS solution. ii. A 5-µL volume of 2.5 M Tris-HCl buffer solution (pH 7.5) and 5 µL of sulfatase are added to the above mixture and incubated at 37 °C for 2 h. iii. After cooling to room temperature, 100 µL acetonitrile is added to the above mixture with stirring. iv. The following procedure is achieved according to the iii–v steps of the above section for ana- ...