Addressing Matrix Effects in Pesticides and their Transformation Product Analysis Using LC-Positive-Electronspray-MS/MS

Abstract

Liquid chromatography-triple quadrupole mass spectrometer (LC/MS/MS) using electrospray ionization (ESI) is a commonly used analytical method for environmental safety even though there are limitations to its robustness. One of the limitations, the matrix effect (ME), is defined as the ionization suppression/enhancement by the co-eluting residual component, which creates large uncertainties in quantification. The objective of this study is to address ME in the analysis of pesticides and their transformation products in water matrices. For a set of 164 environmental samples, which were preconcentrated by a solid-phase extraction, ME was estimated by spiking standard solution containing 27 target chemicals. As a result, ionization suppression occurred in most of the analytes/matrix pairs. Variability in ME was also observed and the variability among analytes was derived from co-eluting matrix component rather than the physicochemical property of each analyte. To overcome ME, the preconcentrated samples were successively diluted and the effective dilution factor was determined. The variability among diluted samples was still observed and therefore ME needs to be confirmed in every sample for reliable quantification. Sample dilution worsens the limit of quantification; however, the limits in the method were maintained below 0.01 µg/L.

The Status Quo of Causal Substance Exploration for Fishy Odor in Raw Water for Taps

“…Takanashi et al focused on 3-methyl-4-nitrophenol (3M4NP), a typical hydrolysate of fenitrothion, and proposed that chloro-5-hydroxy-2-nitrobenzoic acid was possibly generated as a chlorination product of 3M4NP [83]. Kondo et al monitored pesticides and their transformation products in water environments utilizing LC-MS/MS [84]. Kasuga et al analyzed dissolved organic matter (DOM) in eleven major lakes in Japan water using HRMS [85].…”

Simultaneous analysis of seven neonicotinoid pesticides in agricultural products involving solid-phase extraction and surrogate compensation using liquid chromatography-tandem mass spectrometry

“…In order to minimize the effect of matrices on analyte recovery, dilution of the sample solution is a convenient technique. 17,19) However, Stahnke et al reported that the MME varied depending on the pesticide/matrix combination and resulted in the requirement of different dilution factors for the complete elimination of matrix effects, and extreme dilution is not acceptable due to the detectability limitation of the analyzer. 17) The combination of target pesticides and food samples can be substantially altered according to the purpose of the analysis.…”

“…[7][8][9][10][11][12][13] However, matrix effects, such as ionic suppression and enhancement, can reduce analytical reliability, even that of LC-MS/MS. [14][15][16][17][18][19] Several techniques have been developed in order to deal with this problem. The matrix-matched calibration method is one technique to overcome sample matrices by mixing sample matrices from blank samples into the standard solutions.…”