Determination of six Alternaria toxins with UPLC-MS/MS and their occurrence in tomatoes and tomato products from the Swiss market

Abstract

An ultra performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) method was developed for the determination of the Alternaria toxins tenuazonic acid, alternariol, alternariol monomethyl ether, altenuene, altertoxin I and tentoxin. Owing to its instability, altenusin could not be determined. The sample preparation includes an acidic acetonitrile/water/methanol extraction, followed by SPE clean-up step, before injection into the UPLC-MS/MS system. The separation was made on an Acquity UPLC column using a water/acetonitrile gradient with ammonium hydrogen carbonate as a modifier. Matrix compounds of real samples led to enhancement as well as suppression of the target compounds, depending on analyte and matrix. The recoveries were between 58 and 109% at a level of 10 μg/kg. Eighty-five tomato products, consisting of peeled and minced tomatoes, soup and sauces, tomato purées and concentrates, ketchup as well as dried and fresh tomatoes, were taken from the Swiss market in 2010. Tenuazonic acid was found most frequently (81 out of 85 samples) and in the highest levels of up to 790 μg/kg. Alternariol and alternariol monomethyl ether were found in lower concentrations, ranging from <1 to 33 μg/kg for alternariol and <5 to 9 μg/kg for alternariol monomethyl ether. Only a few samples were positive for altenuene and tentoxin. Altertoxin I was never detected.

Survey of Alternaria toxin contamination in food from the German market, using a rapid HPLC-MS/MS approach

“…The peak for TeA is quite broad and also shows some tailing. There are some examples in literature where a better peak shape for TeA is achieved with eluents of (slightly) basic pH values (Lohrey et al 2013;Noser et al 2011). We nevertheless decided to use an acidic pH for the separation of the toxins as basic pH values (or less acidic pH values) fail to separate the pairs of isomers AAL TA 1 /AAL TA 2 and ALT/isoALT.…”

“…The applications of gas chromatography (Scott et al 2006) for the determination of Alternaria toxins are limited due to the laborious derivatization reactions needed. There are up-to-date two methods described in literature for the quantification of AOH, AME, TeA, ALT, ATX-I, and TEN simultaneously (Noser et al 2011;Walravens et al 2014). However, most methods fail to cover all toxins of interest as they are limited to a narrow range of polarity.…”

Validated UPLC-MS/MS Methods To Quantitate Free and Conjugated Alternaria Toxins in Commercially Available Tomato Products and Fruit and Vegetable Juices in Belgium

“…6 Regarding 4, Noser et al 6 reported similar prevalences and concentrations ranges in tomato sauce and concentrate samples, while López et al…”

A Rapid Method with UPLC for the Determination of Fusaric Acid in Fusarium Strains and Commercial Food and Feed Products

“…The extraction of FA from fifteen agricultural products was conducted based on the method described by Noser [26] with some modifications ( Fig. 1).…”