The accurate diagnosis and treatment of poisoning cases involving diquat and paraquat require the precise monitoring of their concentrations in the body. To address this need, researchers have developed a competitive colloidal gold immunochromatographic assay (GICA) strip for qualitative detection, as well as a hydrophilic interaction liquid chromatography with ultraviolet detection (HILIC-UV) method for quantitative assessment. The GICA strip has been validated to achieve a detection limit of 20 ng/mL, with no cross-reactivity with other substances such as glyphosate, deltamethrin, or dichlorvos in spiked serum samples. This suggests that the GICA strip is highly specific and can accurately detect the presence of diquat and paraquat without giving false positives. The HILIC-UV method, on the other hand, has been shown to have a detection limit of 0.2 μg/mL and exhibits excellent linearity for both paraquat and diquat in serum and urine samples. The accuracy of the HILIC-UV method ranges from 86.4% to 111.4%, with a relative standard deviation (RSD) below 10.8%. These results indicate that the HILIC-UV method is highly accurate and reliable for quantitative analysis. The combination of the GICA strip and the HILIC-UV method has been tested on 24 patient specimens, with 21 samples testing positive for diquat and paraquat poisoning. The results show complete consistency between the two methods, with 11 patients diagnosed with paraquat poisoning and six with diquat poisoning. Both of these poisoning types can cause significant impairment of liver, kidney, and coagulation functions, highlighting the importance of accurate and rapid diagnosis. The integration of the GICA strip for rapid qualitative assessment with the HILIC-UV method for quantitative analysis provides a powerful tool for emergency diagnostics, enabling healthcare professionals to quickly and accurately identify diquat and paraquat poisoning cases. Link: https://pubmed.ncbi.nlm.nih.gov/40315593/