Coupling of a streamlined solid-liquid extraction protocol with LC-ESI-MS/MS for the regular oversight of illegal bromate additive use: An accurate and sensitive determination method in preliminary and bakery products.

A reliable solid-liquid extraction protocol coupled with liquid chromatography-electrospray ionization-tandem mass spectrometry in the negative-ion mode was developed and validated for illegal bromate determination in preliminary and bakery products. Crude and dried-treated samples were directly extracted with acetonitrile-water (4:1, v/v). Bromate was determined using a Phenomenex Synergi™ Polar reversed-phase column and MS/MS under multiple reaction monitoring. The chosen solvent efficiently extracted bromate with all applied extraction-assisting techniques (p > 0.05). Although this assay avoids cleanup procedures, matrix effect of <-11% was achieved. Rapid bromate separation in only 8 min was attained by a reversed-phase column. In both commodities, linearity range, R2, recovery%, repeatability, intermediate precision, LOD and LOQ results were 0.05-100 ng mL-1, >0.9999, 88.6-103%, 2.93-9.80% and 9.64-10.10%, 0.015 µg kg-1 and 0.05 µg kg-1, respectively. Out of 288 tested real samples, 13.9% of violations were observed. This high-sensitivity protocol offers effective oversight and consumer protection.

Development and Validation of a Modified QuEChERS protocol Coupled to Liquid Chromatography-Tandem Mass Spectrometry for the Rapid and Accurate Determination of Acrylamide in Cereal-Based Baby Foods.

BACKGROUND: With the widespread consumption by children of cereal-based baby food, acrylamide contamination is a prevalent risk that may have carcinogenic consequences. OBJECTIVE: This study aims to develop and validate a modified QuEChERS protocol (quick, easy, cheap, effective, rugged, and safe) without solvent exchange, followed by rapid separation and accurate determination of acrylamide in cereal-based baby foods using reversed-phase (RP)-LC-MS/MS. METHODS: Samples were extracted using a modified QuEChERS protocol of the AOAC version and cleaned up with basic alumina. Separation was performed on a Phenomenex® Kinetex C18 column (100 Å × 3.5 µm × 4.6 mm × 150 mm) using a gradient elution program with a mobile phase of 10 mM ammonium formate-methanol. Determinations were conducted using electrospray ionization (ESI)-MS/MS in positive-ion mode. RESULTS: Basic alumina yielded clean extracts, resulting in acceptable recovery percentages and a tolerable matrix effect (ME) <5%. This allowed extraction without a solvent exchange step. Efficient separation was achieved at a retention time (tR) of 3.39 ± 0.05 min employing an RP-C18 column with core-shell properties in a relatively short analysis run time of only 5 min. Trueness, precision, LOD, LOQ, linearity range, and R2 results were 92.5-104.6%, RSD ≤12.2%, 5 µg/kg, 20 µg/kg, 4.0-1000.0 µg/kg, and > 0.9999, respectively. The test method applicability was demonstrated by proficiency testing (PT) and 50 real samples of cereal-based baby foods. Most of the tested samples were in violation of acrylamide's established European Union benchmark (40 µg/kg). CONCLUSION: Acetate-buffered QuEChERS protocol in conjunction with optimized amounts of basic alumina was confirmed as an efficient extraction protocol for acrylamide from cereal-based baby foods resulting in optimal method performance. Successful selection of the RP-C18 column is key for selective separation for acrylamide in a relatively short analysis run time. HIGHLIGHTS: The modified AOAC QuEChERS protocol with a dispersive solid phase extraction (d-SPE) of basic alumina assisted in reducing the ME to tolerable levels while maintaining acceptable method performance. The use of an RP-C18 column with core-shell properties enabled a rapid and accurate acrylamide determination.

Simultaneous determination of 200 pesticide residues in honey using gas chromatography-tandem mass spectrometry in conjunction with streamlined quantification approach.

A sensitive, accurate and reliable multi-class GC-MS/MS assay protocol for quantification and confirmation of 200 common agricultural pesticides in honey was developed and validated according to EU guidelines. A modified extraction procedure, based on QuEChERS method (quick, easy, cheap, effective, rugged and safe) was employed. Mass spectrophotometric conditions were individually optimized for each analyte to achieve maximum sensitivity and selectivity in MRM mode. The use of at least two reactions for each compound allowed simultaneous identification and quantification in a single run. The pesticides under investigation were separated in less than 31 min using the ultra-inert capillary column (DB-35MS). For all analytes, neat standard calibration curves in conjunction with correction for matrix effect were successfully employed. The detection limits of the assay ranged from 1.00 to 3.00 ng mL(-1) for the studied pesticides. The developed assay was linear over concentration range of 10.00-500.00 ng mL(-1), with correlation coefficient of more than 0.996. At the LOQ, 81% of the studied pesticides were efficiently recovered in the range of 70.00-120.00%, with CV% less than 15.00% while 99.3% compounds had mean percentage recovery of 60.00-140.00%, with CV% less than 21.00% (N=18, over three different days). The proposed assay was successfully applied for the analysis of the studied pesticide residues in one PT sample and 64 commercial honey samples collected over 1 year from different districts around Egypt. Results revealed that only one honey sample out of the 64 analyzed samples was contaminated with tau-Fluvalinate (10.00 µg kg(-1)). This wide scope assay protocol is applicable for monitoring pesticide residues in honey by national regulatory authorities and accredited labs; that should help ensure safety of such widely used product.

Development and validation of a modified QuEChERS protocol coupled to LC-MS/MS for simultaneous determination of multi-class antibiotic residues in honey.

LC-MS/MS assay was developed and validated according to EU guidelines for determination of nitrofuran metabolites and nitroimidazole residues in honey. Crude samples were acid-treated to liberate matrix-bound residues and a modified QuEChERS protocol was employed. Nitrofurantoin, furazolidone, furaltadone and nitrofurazone were determined via analysis of their metabolites AHD, AOZ, AMOZ and SEM, respectively while nitroimidazole residues; ronidazole (RNZ) and dimetridazole (DMZ) were determined directly. For all analytes, neat standard calibration curves, after correction for matrix effect were successfully employed. Decision limit (CCα) and detection capability (CCß) were below the MRPL for nitrofurans (1.00 µg kg(-1)) and the recommended concentration for nitroimidazole (3.00 µg kg(-1)), respectively. The CCα, CCß, percentage recovery and CV% ranges were 0.12-0.74 µg kg(-1), 0.21-1.27 µg kg(-1), 90.96-104.80% and 2.65-12.58%, respectively. This work is part of the national initiative for establishing a national monitoring program for drug residues in Egyptian honey.

Hazard index, a tool for a long term risk assessment of pesticide residues in some commodities, a pilot study.

Samples of some vegetables were analyzed for pesticides residues using the accredited (QuEChERS) method. The method allowed the determination of 215 compounds of different pesticide chemical groups. LC-MS/MS and GC-MS/MS were used for residues quantification. In a total number of 116 samples, no pesticides residues were detected in 34 samples (29.3%), while 82 samples (70.7%) had detectable pesticide residues, with some samples exceeding the MRLs levels established by the Codex Alimentarius Commission. The hazard index (HI %), representing the long--term risk assessment was in the range of 0.01%-15.04% of the ADI's. The highest exposure was observed for ethion, followed by chlorpyifos, both of them are organophosphates, at 15.04% and 2.45% of ADI respectively. The acute (short-term) exposure was also estimated. Results showed a potential risk for children posed by 3 pesticides, meanwhile, residues of one pesticides showed potential risk to adults (>100% of ARfD). The present work is an attempt to provide a model for the use of WHO template for calculating the short term intake. This model is especially useful for developing countries where information about consumption rate is rather meager.