Determination of aspirin and salicylic acid in uremic patients' plasma using reversed-phase high-performance liquid chromatography

A simple, rapid, and sensitive method for the determination of aspirin and salicylic acid in plasma of uremic patients is reported. After extraction with hexane, aspirin (ASA) and salicylic acid (SA) were quantified by high-performance liquid chromatography (HPLC) with ultraviolet detection at 229 nm. ASA and SA concentrations and peak-height ratios were linearly related up to 20 micrograms/ml. The lower limit of sensitivity was 0.1 microgram/ml for both compounds. The average recoveries of aspirin and salicylic acid were 27 and 54%, respectively. This procedure offers better performance than do previously described methods. The sample clean-up allows quantitation of a low concentration of aspirin in uremic patients' plasma, commonly rich in interfering endogenous substances.

Decline of blood and alveolar toluene concentration following two accidental human poisonings

In two workers admitted to hospital because of a coma due to an accidental occupational exposure to a mixture of solvents, the level of toluene was respectively 823-1122 micrograms/l in the blood and 53-38 micrograms/l in the alveolar air on the second day of admission (36 h after the accidental exposure). On the fifth day, 112 h after exposure, the toluene level was 120-45 micrograms/l in the blood and 3-1 micrograms/l in the alveolar air. The urinary excretion of o-cresol, calculated as a toluene equivalent, was 0.8-0.9 mg on the second day and 1.7-1.6 mg on the third day. Urinary hippuric acid, as a toluene equivalent, was 1.7-1.4 g on the second day and 1.3-0.7 g on the third day. A half-life of between 19 and 21 h was calculated for toluene both in the blood and in the alveolar air.