Analysis of Patulin in Pear- and Apple-Based Foodstuffs by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry

Abstract

A liquid chromatography electrospray ionization tandem mass spectrometry method for the determination of patulin in apple- and pear-based foodstuffs was developed. The sample preparation is based on the QuEChERS procedure involving an initial extraction step with water and acetonitrile, followed by a partitioning step after the addition of magnesium sulfate and sodium chloride. The cleanup was performed by using dispersive solid-phase extraction with a mixture of magnesium sulfate, primary secondary amine sorbent, and n-octadecylsiloxane sorbent added together to the extract. The cleaned extract was finally evaporated and reconstituted in water prior to injection. Quantitation was performed by isotope dilution using ((13)C(7))-patulin as internal standard. The method was first fully validated in three different baby food products including apple-pear juice, apple-pear puree, and infant cereals. Then the scope of application of the method was extended to pear concentrate, raw apples, apple flakes (naturally contaminated), dried apples, and yogurt. The sensitivity achieved by the method in all matrices gave limits of detection (LOD) and quantitation (LOQ) of ≤0.5 and ≤10 μg/kg, respectively, which was compliant with maximum levels settled in Commission Regulation (EC) No. 1881/2006. Method performances for all matrices also fulfilled the criteria established in the CEN/TR 16059:2010 document. Indeed, recoveries were within the 94-104% range; relative standard deviations of repeatability (RSD(r)) and intermediate reproducibility (RSD(IR)) were ≤7.5 and ≤13.0%, respectively, and trueness in an infant apple drink (FAPAS 1642) was measured at 99%.

Design of a Molecularly Imprinted Stir-Bar for Isolation of Patulin in Apple and LC-MS/MS Detection

“…However, the diverse drawbacks of this method (poor stability of patulin under alkaline extraction, poor resolution between patulin and co-extracted hydroxymethylfurfural) have originated interest in alternative options, such as LC methods coupled to mass spectrometry [1]. In the last years, purification with molecularly imprinted polymers and magnetic materials started to be used and they are becoming promising materials in analytical chemistry and, more specifically, in mycotoxins determination [7,8,12,13].…”

“…Patulin (PAT) is an important mycotoxin produced by over 30 genera of mold such as Penicillium, Aspergillus, and Byssochlamys. In particular, Penicillium expansum is recognized as the main source of PAT and it has been commonly associated with apple rot [1]. These molds grow easily in damaged fruit or in derived products such as juices, if storage conditions are deficient.…”

“…The main drawback of UV detection is the poor resolution between PAT and other co-extracted compounds such as hydroxymethylfurfural. To overcome this interference, liquid chromatography may be combined with mass spectrometric determination [1]. As an additional problem, PAT is vulnerable to the alkaline conditions of the previously mentioned extraction method.…”

“…To overcome this interference, liquid chromatography may be combined with mass spectrometric determination [1]. As an additional problem, PAT is vulnerable to the alkaline conditions of the previously mentioned extraction method.…”

<strong>Magnetic molecularly imprinted stirring bar for isolation of patulin using grafting technique</strong>

“…Particularly, Penicillium expansum is known as the main source of PAT and it is commonly associated with apple rot (Desmarchelier et al, 2011). Although, PAT is mainly detected in apples and derived products, it is also found in barley, wheat, corn, silage, pears, grapes and peaches (Smet et al, 2011).…”