Alternate Isotope‐Coded Derivatization Assay: An Isotope Dilution Method Applied to the Quantification of Zearalenone in Maize Flour

Abstract

Low‐cost isotope dilution made easy: An alternate reaction of an analyte in a matrix and in a standard solution with isotope‐labeled or unlabeled derivatizing reagents allows quantification of zearalenone in maize flour without the need for a calibration curve. This is possible by direct calculation of the relative response factor for the analyte/internal standard ratio of the sample (see picture).

Evaluation of Alternate Isotope-Coded Derivatization Assay (AIDA) in the LC–MS/MS analysis of aldehydes in exhaled breath condensate

“…The AIDA method was initially proposed for the LC-MS determination of zearalenone in authentic maize flour samples after derivatization with acetic anhydride but without any sample clean-up and without calibration curve [7]. Since it was expected that the matrix could significantly interfere with the derivatization reaction and affect the analytical precision, a protocol with six independent determinations (three with deuterated and three with protonated standards) for every sample was proposed to obtain accurate results.…”

“…According to the formulas originally proposed for the quantification of zearalenone in maize flour after derivatization with acetic anhydride [7], quantification of the L-derivatized analyte (LA) in the presence of the H-derivatized internal standard (HS), is given by Eq.…”

“…Since it was expected that the matrix could significantly interfere with the derivatization reaction and affect the analytical precision, a protocol with six independent determinations (three with deuterated and three with protonated standards) for every sample was proposed to obtain accurate results. The contribution of sample analysis repeatability on precision was assumed to be negligible and replicate injections were not performed [7].…”

“…In this study, we have investigated another approach, that is the possibility of applying a novel isotope dilution method, named Alternate Isotope-Coded Derivatization Assay (AIDA), originally proposed for the quantification of zearalenone in maize flour after derivatization with acetic anhydride [7], to the quantitative analysis of MDA and 4-HNE in EBC. The method is based on the alternate derivatization of the analyte(s) with reagents that are available in two pure isotopic forms, "light" and "heavy" (L and H, respectively).…”

Isotope-labelling derivatisation: a broadly applicable approach to quantitation of algal toxins by isotope dilution LC-MS/MS

“…A similar approach has been proposed for quantitation of target mycotoxins, avanones and amino acids in complex food matrices by LC-MS when no labelled standard is available. [18][19][20][21][22] With this approach, different isotopomers of the derivatising reagent are used to differentially label the analyte in the sample and in the standard. The labelled standard is then spiked into the sample and used to perform isotope dilution quantitation.…”