A simple and rapid method for determination of paraquat in human urine and plasma by improved solid adsorption using equipment built in-house

A simple and rapid method was developed for clinical naked-eye and quantitative detection of paraquat (PQ) in human plasma and urine samples using built-in-house analytical devices followed by visual colorimetric method and UV–Vis spectrophotometry. A quantitative spectrophotometric method for PQ was also developed based on device built in-house. Different factors influencing the recovery efficiency of PQ such as the pH of the sample solution, the amount of adsorbent, the type and volume of eluent, the extraction and desorption time, the adsorption capacity and sample volume were studied and optimized in detail. Under optimal conditions, the whole analysis time of the naked-eye method was less than 5 min and it provided the detection limit observed with naked eye of 0.2 μg/mL with the detection range between 0.5 and 5.0 μg/mL for paraquat determination. PQ could be detected as low as 6.21 × 10−3 μg/mL in urine and 0.119 μg/mL in plasma with this proposed quantitative spectrophotometric method, respectively. The method was applied in monitoring PQ levels in plasma and urine at different hemoperfusion numbers in local hospitals for patients exposed to PQ poisoning. The detection result could not only enable immediate medical intervention but also benefit patients’ survival.