Development of a single‐run analytical method for the detection of ten multiclass emerging contaminants in agricultural soil using an acetate‐buffered QuEChERS method coupled with LC–MS/MS

Abstract

This study was undertaken to develop and validate a single multiresidue method for the monitoring of ten multiclass emerging contaminants, viz. ceftiofur, clopidol, florfenicol, monensin, salinomycin, sulfamethazine, sulfathiazole, sulfamethoxazole, tiamulin, and tylosin in agricultural soil. Samples were extracted using an acetate-buffered, modified quick, easy, cheap, effective, rugged, and safe method followed by liquid chromatography with tandem mass spectrometric analysis in positive ion mode. Separation on an Eclipse Plus C column was conducted in gradient elution mode using a mobile phase of methanol (A) and distilled water (B), each containing 0.1% formic acid and 5 mM ammonium formate. The linearity of the matrix-matched calibrations, expressed as determination coefficients, was good, with R ≥ 0.9908. The limits of quantification were in the range 0.05-10 μg/kg. Blank soil samples spiked with 4 × and 20 × the limit of quantification provided recovery rates of 60.2-120.3% (except sulfamethoxazole spiked at 4 × the limit of quantification, which gave 131.9%) with a relative standard deviation < 13% (except clopidol spiked at 20 × the limit of quantification, which gave 25.2%). This method was successfully applied to the monitoring of 51 field-incurred agricultural loamy-sand soil samples collected from 17 provincial areas throughout the Korean Peninsula. The detected and quantified drugs were clopidol (≤ 4.8 μg/kg), sulfathiazole (≤ 7.7 μg/kg), sulfamethazine (≤ 6.6 μg/kg), tiamulin (≤ 10.0 μg/kg), and tylosin (≤ 5.3 μg/kg). The developed method is simple and versatile, and can be used to monitor various classes of veterinary drugs in soil.

Development of Methods for the Determination of PhACs in Soil/Earthworm/Crop System Irrigated with Reclaimed Water

“…Furthermore, it was used by the QuEChERS fathers when the method was first introduced [19]. ACN was used as extraction solvent in all the studies dealing with soil extraction by QuEChERS technique, besides water or McIlvaine buffer as hydration solvent of the sample [101][102][103][104][105][106]. Hydration of the soil with water is important to weaken the interactions of the target analytes with the adsorption sites of the soil humic substance, promoting desorption and allowing the ACN to obtain better access to the soil pores.…”

“…Only Meng and coworkers employed McIlvaine buffer in their extraction procedure [105]. Besides, the acidification of the hydration solution and/or ACN with hydrochloric acid or acetic acid has shown to improve analyte recoveries [101][102][103][104]. Three QuEChERS salts are known which are used intensively: (1) the original non-buffered method (MgSO 4 + NaCl), (2) the AOAC method with acetate buffer (MgSO 4 + CH 3 COONa), and (3) the EN method with citrate buffer (MgSO 4 + C 6 H 5 Na 3 O 7 • 2H 2 O + Na 2 C 6 H 6 O7 • 1.5H 2 O).…”

“…In the EN method, the citrate buffer provides a pH of 5-5.5, while in the AOAC method, the acetate buffer provides a more acidic pH of 4.8 [108]. Higher recoveries and bigger number of compounds were extracted using AOAC method [103,104,106]. This is referred to the acidic conditions obtained by citrate buffer, which improves the extraction of some pharmaceuticals such as sulfonamides, macrolides, and ß-lactams.…”

“…The C18 is nearly always used in all the reported studies, either solely or in combination with MgSO 4 and PSA. Lee and coworkers used C18 sorbent solely for extract clean-up, and satisfactory recoveries were obtained ranging between 60.2 and 120.3% [103]. The addition of magnesium sulfate and primary secondary amines was excluded in their study, because the first liberates energy that might influence on the stability of the tested compounds whereas the second have the ability to chelate/bind with compounds such as sulfonamides.…”

Affinity extraction of emerging contaminants from water based on bovine serum albumin as a binding agent

“…Over the last two decades there has been increasing interest in biologically-active contaminants in environmental samples such as water [1][2][3][4][5][6][7][8][9][10][11][12][13]. These contaminants can arise from municipal, industrial, and agricultural sources and include many substances whose potential effects on the environment and human health are not fully understood and for which regulations are not yet in place [1,2].…”