Quantitative Determination of Plasma and Urine Paraquat Concentrations using Spectroscopic Method / 대한진단검사의학회지

ABSTRACT

BACKGROUND: It is well known that plasma paraquat concentration is one of the most important prognostic indicators for paraquat poisoning. Quantitative analyses of paraquat, however, are not generally used in clinical laboratories. In this work, we evaluated the second-derivative spectroscop-ic method for quantitation of paraquat in plasma and urine, and investigated the clinical significance in patients with paraquat poisoning. METHODS: Linearity, precision, interferences, and comparison with high-performance liquid chro-matography (HPLC) were evaluated in 20 paraquat-poisoning cases using the UV-160 A recording spectrophotometer. The relationship of plasma and urine paraquat concentrations with the clinical outcomes was also studied. RESULTS: The within-run and between-day coefficients of variation (CV) for groups of low and high levels were less than 5%. The derivative amplitude was linearly related to paraquat concentra-tion through the range from 0.5 to 10 ng/mL. The correlation coefficient (r) between spectrophotom-etry and HPLC was 0.992. The accuracy for predicting the outcome for patients based on plasma paraquat concentration was 84.6%. The urine paraquat levels on admission were more than 10 ng/ mL in all of the 9 non-survivors group and in 5 out of 11 of the survivors group. The eliminating rates for plasma and urine paraquat concentrations by extracorporeal procedures were not statistically different between the two groups. CONCLUSIONS: Second-derivative spectroscopic methods for quantitation of paraquat showed an acceptable performance and suitable procedure for clinical laboratory use and it was thought to be seful in assessing the severity and in predicting the prognosis for paraquat poisoning.