Targeted Multiresidue Method for the Analysis of Different Classes of Pesticides in Agro-Food Industrial Sludge by Liquid Chromatography Tandem Mass Spectrometry

Abstract

Sludge generated after washing of fruits and vegetables during agro-food processes is a complex matrix and selective methods for the identification and quantification of pesticides’ residues are necessary in order to achieve a sustainable and effective management of the total sewage. The present work describes the development and validation of a reliable, simple and fast analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of 47 pesticides of different chemical classes, including organosphosphates, pyrethroids, neonicotinoids, triazoles and others, in sludge samples after QuEChERS sample preparation. The necessity of the individual steps of QuEChERS was investigated and the LC-ESI-MS/MS conditions were optimized to achieve maximum sensitivity of the target analytes. The method limits of detection (LODs) ranged between 0.0005 mg/kg (imidacloprid) and 0.05 mg/kg (beta cyfluthrin). The recoveries ranged between 71–120% and the repeatability of the method was ≤25% expressed as relative standard deviation. The method was applied to sludge samples generated after washing of fruits in an agro-fruit-packaging unit in Greece. The results showed the presence of 37 pesticides’ active substances with concentrations ranging from low ppbs, such as fludioxinil (5 μg/kg) up to low ppms such as beta cyfluthrin (3.5 mg/kg) and with their sum concentration reaching up to 19 mg/kg.

Pharmaceuticals Account for a Significant Proportion of the Extractable Organic Fluorine in Municipal Wastewater Treatment Plant Sludge

“…It contains two fluorine atoms and accounted for ∼0.2% of the EOF (6.1 ± 3.6 ng/g dw; CL1). Fludioxonil was reported qualitatively in fruits sold in Swedish supermarkets, soils from Switzerland, and sludge from Greece, , and quantitatively in agro-food industry sludge from Greece (5–680 ng/g dw) …”

“…Fludioxonil was reported qualitatively in fruits sold in Swedish supermarkets, 70 soils from Switzerland, and sludge from Greece, 71,72 and quantitatively in agro-food industry sludge from Greece (5−680 ng/g dw). 73 In total, fluoropharmaceuticals, their TPs, and the fluoropesticide made up ∼22% of the organofluorine mass balance in sewage sludge, whereas conventional PFAS (targets reported previously 22 and newly detected substances) made up only ∼5.1% (Figure 1). (discussed in detail in the SI) suggests that these values may be conservative.…”

Pharmaceuticals account for a significant proportion of the extractable organic fluorine in municipal wastewater treatment plant sludge

“…Fludioxonil was reported qualitatively in fruits sold in Swedish supermarkets, 70 soils from Switzerland and sludge from Greece, 71,72 and quantitatively in agro-food industry sludge from Greece (5-680 ng/g dw). 73 In total, fluoropharmaceuticals, their TPs, and the fluoropesticide made up ~22% of the organofluorine mass balance in sewage sludge, whereas conventional PFAS (targets reported previously 22 and newly detected substances) make up only ~ 5.1% (Figure 1). The impact of semi-quantification error (discussed in detail in the SI) suggests that these values may be conservative.…”

Development of Analytical Methods to Analyze Pesticide Residues

“…Maragou et al [ 7 ] developed and validated a LC-ESI-MS/MS triple quadrupole method for the determination of 47 pesticides in sludge samples after QuEChERS sample preparation. Pesticides with different physico-chemical properties such as Log Pow values between −0.24 to 7.02 were included.…”