Quantitative determination of glufosinate in biological samples by liquid chromatography with ultraviolet detection after p-nitrobenzoyl derivatization.
We have established a new HPLC method for derivatizing and quantifying glufosinate (GLUF) in human serum and urine using p-nitrobenzoyl chloride (PNBC). The p-nitrobenzoyl derivative of GLUF (PNB-GLUF) was produced quantitatively over 10 min at room temperature. PNB-GLUF possesses the property of ultraviolet (UV) light absorption with a lambda(max) of 272.8 nm, and was isolated from biological specimens by reversed-phase chromatography using Inertsil Ph-3. In experiments at a UV wavelength of 273 nm, GLUF has a quantitative detection limit of 0.005 microg/ml, and when it was added to both serum and urine to yield concentrations of 0.1-1000 microg/ml, its recovery rate was quite satisfactory: at least 93.8% in all cases. Further, the measured amounts of GLUF in 23 serum samples from patients intoxicated by ingestion of GLUF compared favorably with those obtained by fluorescence derivatization-HPLC using 9-fluorenylmethyl chloroformate (R=0.998). This technique of analysis is, in addition, applicable for Glyphosat, which possesses a chemical structure resembling that of GLUF, and it will be of great use in the determination of these two compounds.
A toxicokinetic analysis in a patient with acute glufosinate poisoning
Incidents of poisoning in humans caused by the ingestion of the glufosinate ammonium containing herbicides are gradually increasing in Japan. This poisoning is characterized by various neurological symptoms such as disturbances of consciousness, convulsions and apnea which appear after an asymptomatic interval of several hours. We studied the toxicokinetics of glufosinate in a patient with this poisoning successfully treated without extracorporeal hemopurification. A 65-year-old male ingested BASTA, which contains 20% w/v of glufosinate ammonium, about 300 ml, more than the estimated human toxic dose. Four and a half hours after ingestion, he showed speech ataxia and systemic tremor. He was prophylactically intubated before the occurrence of serious respiratory failure. After 5 days of artificial ventilation he was extubated and discharged without any sequelae. We studied the serial change of serum glufosinate concentration every 3-6 h and assessed the urinary excretion of glufosinate every 24 h. The absorbed amount of glufosinate was estimated from the cumulative excreted in urine. Toxicokinetic analysis was performed using the two-compartment model. The changes in serum glufosinate concentration exhibited T1/2α of 1.84 and T1/2α of 9.59 h. The apparent distribution volume at b-phase and the total body clearance were 1.44 l/kg and 86.6 ml/min, respectively. Renal clearance was estimated to be 77.9 ml/ min. The indication for extracorporeal hemopurification for this poisoning has been discussed.
Quantitative determination of the fatty acid composition of human serum lipids by high-performance liquid chromatography.
A high-performance liquid chromatographic method for the analysis of the fatty acid composition of human serum lipids with fluorescence detection was examined. Both free and total fatty acids extracted from serum were derivatized with 9-anthryldiazomethane and were analysed using methanol-water (94.7:5.3) as mobile phase. Twelve kinds of fatty acid were detected, both in the free and total fatty acids, and were well separated. Concentrations of individual fatty acids of serum lipids were estimated from an internal standard, heptadecanoic acid. The results correlated well with those from two other quantitative analyses. These results indicate that the high-performance liquid chromatographic analysis of fatty acids is a reliable method for determining individual fatty acids of human serum lipids. The compositions of free fatty acids and total fatty acids of serum lipids were analysed and compared in 27 normal subjects, 27 diabetics, and 20 angina pectoris patients by this method.