A simple and economical method of gas chromatography-mass spectrometry to determine the presence of 6 pesticides in human plasma and its clinical application in patients with acute poisoning

Simple determination of dichlorvos in cases of fatal intoxication by gas Chromatography-Mass spectrometry

Dichlorvos (DDVP) is an organophosphorous insecticide which is classified as "highly hazardous" Class 1B chemical by World Health Organization (WHO) and largely misused for the purpose of self-poisoning in developing countries. Forensic toxicology laboratories are routinely encountering cases of pesticide poisoning due to their fatal intoxication. Herein; a method is described based on vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS) for the determination of an organophosphorous insecticide; dichlorvos (DDVP) in human autopsy samples (blood, stomach content and liver). Under the optimum conditions, the method was found to be linear in the range of 0.5-10 µg mL^-1 and 1.5-10 µg g^-1 for blood and tissue samples, respectively. Limit of quantification was set at 0.55 µg mL^-1 and 1.1 µg g^-1 for blood and tissue samples, respectively. Intraday and inter-day precisions were less than 8 and 12 %, respectively. Good recoveries in the range of 86-95 % were obtained for the proposed procedure. The method has been satisfactorily applied for the determination of DDVP in autopsy samples from two different cases received in our laboratory. In comparison to previous methods; the proposed method is relatively short, high sample throughput, inexpensive and adheres to the principles of green analytical chemistry (GAC) for determination of DDVP in human autopsy samples. The method can be adopted in forensic toxicological laboratories for analysis of DDVP in autopsy samples. In addition, the green character of the proposed method was evaluated using ComplexGAPI procedure.

Chromatographic techniques for the analysis of organophosphate pesticides with their extraction approach: a review (2015-2020)

In agriculture, a wide range of OPPs has been employed to boost crop yield, quality, and storage life. However, due to the ever-increasing population and rapid urbanization, pesticide use has surged in recent years. These compounds are exceedingly poisonous to humans, and despite the fact that specific legislation prohibits their use, the frequency of toxic and/or fatal incidents, as well as current statistics, suggest that they are currently accessible. As a result, determining the exposure to these substances as well as their detection (and that of their metabolites) in different types of exposed samples has become a hot issue in terms of quality and safety concerns. However, developing tools for the evaluation of these substances is a critical challenge for laboratories. Various chromatographic-based methods reported in the period of 2015-2020 have been developed, which are summarized and critically reviewed in this article, including the extraction of the target OPPs from different kinds of matrices. A comparison among the extraction and analysis techniques has been made in the current review article.

Nanomaterial-enhanced 3D-printed sensor platform for simultaneous detection of atrazine and acetochlor

The widespread use of herbicides in agriculture and gardening causes environmental and safety issues such as water pollution. Thus, efficient and convenient analysis of the levels of herbicide residues is of significant importance. Here, we employed 3D-printing to design a multiplex immunosensor for simultaneous detection of two widely used herbicides, atrazine and acetochlor. Multiplexing was achieved through customization of a lateral flow immunoassay, and then integrated with an electrochemical analyzer for ultrasensitive detection. Quantification of herbicide residues was realized through the detection of a novel nanomaterial label, the mesoporous core-shell palladium@platium nanoparticle (Pd@Pt NP), for its outstanding peroxidase-like property. During the electrochemical analysis, the catalytic activity of Pd@Pt NPs on the redox reaction between thionin acetate and hydrogen peroxide provided an electrochemically driven signal that accurately indicated the level of herbicide residues. Using this Nanomaterial-enhanced multiplex electrochemical immunosensing (NEMEIS) system, simultaneous detection of atrazine and acetochlor was realized with a limit of detection of 0.24 ppb and 3.2 ppb, respectively. To further evaluate the feasibility, the optimized NEMEIS was employed for detection in atrazine and acetochlor residue-containing spiked samples, and an overall recovery with 90.8% - 117% range was obtained. The NEMEIS constructed with the aid of 3D-printing provides a rapid, precise, economical, and portable detection device for herbicides, and its success suggests potential broad applications in chemical analysis, biosensors and point-of-care monitoring.