Ochratoxin A in Chinese dried jujube: method development and survey

Abstract

A method was developed for the determination of the mycotoxin ochratoxin A in dried jujube (Zizyphus jujuba Miller) using alkaline methanolic extraction, immunoaffinity column clean-up (IAC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination. The limit of detection (LOD) was 0.01 μg kg(-1) and limit of quantification (LOQ) was 0.03 μg kg(-1). The average recoveries were 82%, 98% and 115% at 5, 0.5 and 0.1 μg kg(-1) spiked levels with relative standard deviations (RSD) of 2.9%, 5.2% and 9.2% accordingly. The method showed good linearity for both solvent standard calibration and matrix-matched standard calibration with correlation coefficients of 0.9998 and 0.9997 respectively. The intra-day precision RSD was 3.3% and the inter-day precision RSD was 4.0%. In addition, there was almost no matrix interference in LC-MS/MS detection after the IAC clean-up process. The proposed analytical set-up was successfully used to test 20 samples that were collected from local markets and stores. The results showed that all the samples were positive and the amount of OTA ranged from < 0.01 to 0.18 μg kg(-1), with a mean level of 0.14 μg kg(-1). In spite of the high positive rate, samples with this level would not cause significant health effects after consumption.

Ochratoxin A in human blood plasma samples from apparently healthy volunteers in Nanjing, China

“…China is one of the countries with the largest agricultural production and consumption, and OTA has been detected in different foodstuffs, such as cereal (Liang et al 2015), dried fruit products (Zhang et al 2014;Zhang et al 2015), wine and beer (Wu et al 2011). However, no publications except of a recent study from our group have assessed the OTA exposure levels of the Chinese population by monitoring its biomarkers, to the best of our knowledge.…”

Occurrence of Mycotoxins in Dried Fruits Worldwide, with a Focus on Aflatoxins and Ochratoxin A: A Review

“…None of the five goji fruit samples from China had AFB 1 , whereas three of them contained OTA with levels of 1.11–2.08 μg/kg [ 65 ]. For dried jujube from Beijing, China, all samples ( n = 20) from the year 2013 were contaminated with OTA, but at very low concentrations, with a maximum of 0.18 μg/kg [ 115 ].…”

The Occurrence and Contamination Level of Ochratoxin A in Plant and Animal-Derived Food Commodities

“…Another survey collected 195 raisins from 9 provinces, and only 3 samples were contaminated, with levels of 0.18-10.14 µg/kg [88]. The situation was worse for dried jujube [89]. All 20 collected samples were contaminated, with a maximum concentration of 0.18 µg/kg.…”