Survey of low-level endocrine disrupting pesticides in food matrices in Slovakia

Abstract

The search on endocrine disrupting chemicals (EDCs) in non-fatty food was evaluated. A fast, high-throughput, accurate, multiresidue method for the analysis of selected EDC pesticides in fruit and vegetable food samples was developed. The QuEChERS technique was used for sample preparation. Fast GC-MS was performed with a narrow-bore capillary column and a quadrupole benchtop detector with electron ionization (EI) and negative chemical ionization (NCI). A part of the work was devoted to the comparison of NCI versus EI approach concerning the sensitivity of detection and to the study of selectivity enhancement in NCI mode. Matrix-matched standard solutions were utilized for calibration. The methods validation was performed. Fortification studies at 1, 5, 10 and 250 mg kg À1 for 35 pesticides in EI mode and 0.1, 1, 5 and 250 mg kg À1 for 28 pesticides in NCI mode were performed. Average recoveries for each fortification level ranged from 70 to 110% with 480% of recoveries between 90 and 110%. Limits of quantification (LOQs) were established at 5 mg kg À1 for EI and at 1 mg kg À1 for NCI mode, which is lower than the lowest maximum residue level (MRL) value set by the European Commission in fruit and vegetables. The developed and validated fast GC-MS method was successfully applied to the search of EDC pesticides at ultratrace concentration level in real fruit and vegetable samples in Slovakia. Thirty-four samples of 20 different commodities were analyzed. Seven samples contained residues of three or more EDCs pesticides.

Analysis of Endocrine Disrupting Pesticides by Capillary GC with Mass Spectrometric Detection

“…[50]. An important objective was to assess the occurrence of pesticides from different chemical classes suspected or known to act as endocrine disrupters in fruit and vegetable samples available on the market in Slovakia.…”

“…To solve this problem, four types of quantitation methods can be used in pesticide residues analysis to compensate for the matrix effects [ 66 , 67 , 68 ]. For the analysis of EDCs/EDPs the same approaches to eliminate matrix effects in various matrices [ 17 , 41 ] are used: (i) method of standard addition [ 47 , 50 , 58 ]; (ii) use of isotopically labeled internal standards [ 55 , 56 ]; (iii) use of matrix-matched standards [ 45 , 46 , 48 , 49 , 50 ]; and (iv) use of analyte protectants (APs) [ 48 , 49 ]. For matrix-matched standardization the bracketing sequence of samples is recommended for better long term stability.…”

“…For matrix-matched standardization the bracketing sequence of samples is recommended for better long term stability. Clean-up of extracts and utilization of retention gap can additionally reduce matrix effects [ 45 , 46 , 48 , 49 , 50 , 69 ].…”

“…Trace and ultra-trace concentration levels of pesticide residues in samples require non-splitting injection techniques. Splitless (SSL) [ 55 , 56 , 57 , 59 , 62 , 63 , 64 , 65 ], programmable temperature vaporizer (PTV) in “cold splitless” mode or “solvent vent” mode [ 15 , 45 , 46 , 47 , 48 , 49 , 50 , 52 , 53 , 54 , 58 ] are well suited ( Table 4 ). For separation purposes, semi-polar stationary phases of analytical columns are used in general.…”

“…The benefits of the developed fast GC-MS methods with narrow-bore column for selected EDPs in non-fatty food compared to conventional GC [ 45 ] was published by Húšková et al [ 46 , 48 ] and Hrouzková et al [ 50 ]. The QuEChERS method was used for preparation of extracts of fruit and vegetables.…”