Quantitation of Mycotoxins in Four Food Matrices Comparing Stable Isotope Dilution Assay (SIDA) with Matrix-Matched Calibration Methods by LC–MS/MS

Author(s): Dan Li; Justin A. Steimling; Joseph D. Konschnik, Scott L. Grossman; Ty W. Kahler
Restek Corporation

Published By: Journal of AOAC International

Year of Publication: 2019

Link: https://www.ingentaconnect.com/content/aoac/jaoac/pre-prints/content-jaoac_190028

Abstract: Background: Mycotoxins are big concerns in food safety. Analytical methods are important for the evaluation of mycotoxins in different food commodities. Objective: In this study, stable isotope dilution assay (SIDA) was compared with a matrix-matched calibration method for the quantification of mycotoxins in four different commercially available commodities and two reference materials. Methods: All samples were extracted with water–acetonitrile (50+50, v/v), followed by filtration and LC–tandem MS analysis. Results: SIDA calibration accuracies ranged from 78.6 to 112% with relative SDs (RSDs) ≤16% across all four matrices. The majority of the recoveries across all matrices ranged from 70 to 120% with RSDs <11%. Of the four mycotoxins in the reference materials analyzed, only three had 13C-internal standard (IS), whereas the fourth was quantified using a closely eluting 13C-IS for a different mycotoxin. Mycotoxins paired with their corresponding 13C-IS had accuracies >90%, whereas accuracies for the mismatched mycotoxin/13C-IS were <14%. Conclusions: When 13C-IS are not available, matrix-matched calibration was also evaluated as an alternative to quantitating target mycotoxins. The use of 13C-IS is the best way to dynamically account for prevalent matrix effects, but matrix matching provides a viable alternative. Highlights: The study compared SIDA and matrix-matched calibration methods in terms of recovery, efficiency, advantages, and limitations for LC-MS based mycotoxin analysis

New MOSH/MOAH Retention Time Standard Ensures Easy, Accurate Integration

Restek is pleased to announce the launch of a new standard formulation that was developed specifically for methods that couple LC with GC-FID to determine mineral oil hydrocarbon contaminants that migrate from processing equipment and packaging into food. This 10-component mix contains both mineral oil saturated hydrocarbon (MOSH) and mineral oil aromatic hydrocarbon (MOAH) markers that are used to accurately identify GC retention time limits for integration. The new standard complements an existing Restek mix that is used to correctly cut the LC fractions for subsequent GC-FID analysis. Both standards are certified reference materials (CRM) manufactured and QC-tested in ISO-accredited labs.

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Analytical Method for Polycyclic Aromatic Hydrocarbons (PAHs) in Yerba Mate Tea Using Modified QuEChERS, Solid Phase Extraction and GC-TOFMS and GC-MS/MS

Author(s): Julie Kowalski, Amanda Rigdon, and Jack Cochran
Restek Corporation

Published By: Restek Corporation

Year of Publication: 2015

Link: http://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFAN2086-UNV

Abstract: This application note describes the development of an analytical method for PAHs in tea that allows analysts to more quickly and accurately characterize target PAHs. Sample preparation is based on a modified QuEChERS extraction and solid phase extraction sample cleanup. Both GC-TOFMS and GC-MS/MS techniques were used and analyses were optimized for resolution of isobaric compounds, as well as for maintaining a reasonable analysis time.

Accurately Detect and Quantify 204 Pesticides of Global Food Safety Concern by LC-MS/MS

Restek LC-MS/MS Multi-Residue Pesticide KitStop spending your time and money developing LC-MS/MS multi-residue pesticide methods and mixing reference standards when you could be running samples! Restek’s trusted food safety experts have already done the work for you—with guaranteed accuracy and at a lower cost.

Restek’s new certified reference materials (CRMs) for LC-MS/MS multi-residue pesticide analysis eliminate the need to source, purchase, and store individual materials along with the need to prepare your own mixes. Choose separate ampuls for mix-and-match customization or a complete kit that contains 204 compounds of interest, covering many LC-determined pesticides listed by government agencies. Designed for maximum shelf life, stability, and chromatographic performance, each standard ships with support documentation detailing Restek’s rigorous in-house quantitative testing. They even offer an optimized multi-residue pesticide method—including conditions and downloadable transition tables—free of charge.

Set up, verify, and validate your pesticide-screening methods in less time, with proven confidence, and at a significantly reduced cost by turning to Restek’s ISO-accredited labs for your LC-MS/MS multi-residue pesticide certified reference materials. For added convenience and unbeatable results, also consider their internal standards, Ultra and Pinnacle® DB LC columns, and Q-sep™ QuEChERS sample prep products.

Learn more at www.restek.com/LC-multiresidue

Mitigate Matrix Interference With New Isotopically Labeled Pesticide Residue Internal Standards From Restek

pesticide_standard_prAny food safety chemist can attest that interference is a major concern when performing pesticide residue analysis. But with the release of its expanded line of internal and surrogate reference standards, Restek now offers enough options to mitigate interference in nearly any matrix!

Isotopically labeled to provide the best approach for pesticide residue quantification, these new internal standards are economically priced and compatible with both LC-MS and GC-MS applications. They are even useful for optimizing LC-MS/MS system performance. Like all of the certified reference materials (CRMs) manufactured and QC-tested in Restek’s ISO-accredited labs, they can also help you satisfy your ISO requirements with ease.

 Compound

CAS#

Solvent

Conc. (μg/mL)

cat.#

atrazine-d5

163165-75-1

Acetonitrile

100

31984

carbaryl-d7

362049-56-7

Acetonitrile

100

31985

diazinon-d10 (diethyl-d10)

100155-47-3

Acetonitrile

100

31986

dichlorvos-d6

203645-53-8

Acetone

100

31987

dimethoate-d6

1219794-81-6

Acetonitrile

100

31988

diuron-d6

1007536-67-5

Acetonitrile

100

31989

linuron-d6

330-55-2

Acetonitrile

100

31990

As much as ever, Restek is your complete supplier for world-class food safety analysis: pesticide reference standard mixes and internal/surrogate standards, GC and LC columns and accessories, QuEChERS products, and more.

You will find a full selection of internal pesticide residue standards at www.restek.com