The Study On The Determination Of Eight Highly Polar Poisons (Including Glyphosate) In Biological Matrices By IC-MS

In light of the practical needs of forensic science laboratories handling cases involving highly polar poisons,this paper presents a study of eight highly polar poisons,including fluoroacetic acid,glyphosate,aminomethylphosphonic acid(AMPA),N-Acetyl glyphosate,glufosinate,N-acetyl glufosinate,N-acetamidomethyl phosphate and 3-methylphosphinico propionic acid(3-MPPA),using ion chromatography(IC)and ion chromatography tandem mass spectrometry(IC-MS).IC and IC-MS methods were developed for the screening of the above eight highly polar poisons,and various pretreatment methods such as acetonitrile precipitation of protein and accelerated solvent extraction,were compared and optimized for specific targets and biological samples.Ultimately,the methods for the screening of glyphosate and other eight highly polar poisons in biological samples by IC and IC-MS were constructed.The pretreatment methods were optimized efficiently and conveniently,and the detection methods were sensitive and stable,meeting the qualitative and quantitative analysis requirements.The methods have effectively addressed the complex pretreatment and low detection efficiency issues associated with traditional detection methods,while also enriching the types of samples,filling the technical gap for using IC-MS to detect the above substances in biological samples.This study provides technical support for the detection and screening of highly polar poisons in biological samples,with contributions that include:(1)A method for the determination of glyphosate and other five highly polar poisons in human blood and urine samples by IC was established.Acetonitrile was used as the organic solvent for protein precipitation.After protein precipitation,the samples were purified by Dionex On Guard II RP and Ag/H solid phase extraction columns.After purification,the mixtures were separated by the Dionex Ion Pac AS11-HC,AS19,or AS20ion chromatography column with KOH solution as the eluent.We then detected the samples with a conductivity detector,using an external standard method for quantification.The results showed that the linear relationships of the six target compounds in blood and urine were goodwithin their respective concentration ranges,and the correlation coefficient was greater than 0.99,with limits of detection(LOD)ranging from0.02–0.15 mg/L and 0.02–0.13 mg/L,and limits of quantification(LOQ)ranging from0.08–0.49 mg/L and 0.07–0.43 mg/L.Under low,medium,and high concentration standards,the recoveries in blood and urine were 85.5%–111.9%and 85.8%–112.9%,respectively.The intra-day RSDs(n=6)for blood and urine were 0.1%–2.5%and 0.1%–2.6%,respectively,while the inter-day RSDs(n=6)were 0.9%–4.9%and 1.0%–4.7%,respectively.The matrix effect of this method in blood and urine were-4.58%–8.76%and-4.67%–7.91%.This method does not require complex derivatization or other time-consuming pretreatments.It is efficient and has good separation,but still has some disadvantages,such as poor performance for AMPA detection and inability to complete all substance detection in one step,requiring further optimization.(2)A method for the determination of glyphosate and other six highly polar poisons in blood and urine samples by IC-MS was established.We used acetonitrile to precipitate proteins,Dionex On Guard II RP solid phase extraction columns to purify the samples,and AS20 ion chromatography columns to separate.Triple quadrupole mass spectrometry with MS/MS(ESI~-)in multiple reaction monitoring(MRM)mode was used to detect the samples.The results showed that the seven target compounds had a good linear correlation in blood and urine within their respective concentration ranges,and the correlation coefficient was greater than 0.99,with LOD ranging from 0.02–0.26μg/L and 0.03–0.28μg/L,and LOQ ranging from 0.08–0.88μg/L and 0.11–0.92μg/L,respectively.Under low,medium,and high concentration standards,the recoveries were 99.0%–116.4%and83.8%–105.3%,respectively.The intra-day RSDs(n=6)for blood and urine were 0.2%–3.8%and 0.5%–4.7%,respectively,while the inter-day RSDs(n=6)were 2.8%–7.0%to2.2%–7.1%,respectively.The matrix effect of this method in blood and urine were-13.08%–0.40%and-14.45%–3.59%.Compared to the IC method,the IC-MS method avoids the need for Ag/H solid phase extraction column to remove chlorine ions in pretreatment.In the detection aspect,IC-MS uses ion pair information of target substances for qualitative analysis,successfully solving the problem of poor performance for AMPA detection and realizing simultaneous detection of multiple substances in a short time.This method is simple and fast,and has high sensitivity,which fully compensates for the shortcomings of the IC method.(3)A method for the determination of fluoroacetic acid in human blood and urine by accelerated solvent extraction–ion chromatography mass spectrometry was established.Deionized water was used as the extraction solvent,and blood and urine samples were processed by accelerated solvent extractor.The supernatant was sequentially collected via centrifugal ultrafiltration and 0.22μm membrane filtration,diluted 50 times,and then injected into the chromatographic column for detection.An Ion Pac AS20 IC column was used for isocratic elution with 15.0 mmol/L KOH solution as the eluent.The effluent was passed through a suppressor and into a triple quadrupole mass spectrometer,which was used to perform MS/MS(ESI~-)in MRM mode.The results showed a good linear relationship for fluoroacetic acid in the range of 0.5–500.0μg/L,and the correlation coefficient was greater than 0.99,with LOD and LOQ of 0.14 and 0.47μg/L,respectively.The recoveries of fluoroacetic acid in blood and urine were 93.4%–95.8%and 96.2%–98.4%,respectively.The intra-day RSDs for blood and urine were 0.8%–1.6%and 0.2%–1.0%,respectively,while the inter-day RSDs were 2.3%–3.8%and 3.9%–6.9%,respectively.Further investigation revealed that the matrix effects of this method in blood and urine,at-7.4%and-3.0%,respectively,were fairly weak.The experiments showed that the accelerated solvent extraction had good protein precipitation effect and high extraction efficiency,while avoided using organic solvent which may damage IC columns.Compared to LC-MS and other detection methods,the IC-MS method does not require derivatization,and has high sensitivity and excellent accuracy.In summary,the developed method satisfies the requirements of fluoroacetic acid analysis.Additionally,it is suitable for the rapid detection of fluoroacetic acid in human blood and urine,providing a new idea for the detection of fluoroacetic acid poisons in the field of forensic science.