Abstract:

A QuEChERS-ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of five Alternaria toxins including tenuazonic acid, tentoxin, aletrnariol monomethyl ether, alternariol and altenuene in fruit puree for infants was established. A fruit puree sample was extracted with a mixture solution of acetonitrile∶water∶formic acid (79∶20∶1, V/V/V), followed by a salting-out extraction using 0.5 g anhydrous CH₃COONa and 0.5 g NaCl coupled with a dehydration step with the addition of 4 g anhydrous MgSO₄, and a purification step with 100 mg C18. An ACQUITY UPLC^® HSS T3 column (2.1 mm×100 mm, 1.8 μm) was used for chromatographic separation. The mobile phase consisted of 5 mmol·L^-1 ammonium acetate aqueous solution and methanol and a gradient elution program was applied. The measurement was carried out under the condition of multiple response monitoring mode and electrospray ion source. The matrix-matched external standard was used for quantitative analysis. The linearity of the method was in the range of 0.1-200 μg·L^-1, with the determination coefficients (R²) greater than 0.998. The limits of detection and quantification were 0.1 μg·kg^-1 and 0.3 μg·kg^-1, respectively. The average recoveries were in the range of 73.8% to 118.0% with the relative standard deviations of 2.3% to 8.5%. The results demonstrated that the developed method was efficient, accurate, sensitive, and suitable for the quantitative determination of five Alternaria toxins in fruit puree for infants.

Key words: fruit puree, Alternaria toxin, food safety