Multi-class analysis for simultaneous determination of pesticides, mycotoxins, process-induced toxicants and packaging contaminants in tea

Abstract

This study attempts at uniting the analysis of four different classes of contaminants for both liquid and solid tea samples. A total of 32 compounds, classified as pesticides, mycotoxins, process-induced toxicants or packaging contaminants, were carefully chosen for their diversity of structures and physicochemical properties. The proposed method combines a sample treatment strategy coming from metabolomics with liquid chromatography analysis using a silica bonded C18-pentafluorophenyl column coupled to high resolution mass spectrometry. For tea brew, dilute and shoot method provides good quantification (70-120% recoveries and <20% RSD) for more than 80% of compounds. For tea leaves, strong matrix effects are observed, thus, matrix-matched calibration is required to reach good performances, i.e. 63% of compounds quantified and 81% detected at 10µg/kg. Finally, method performances were evaluated against existing regulations, and it appears that 69% of contaminants are quantified and 91% detected at levels lower than their respective European regulation limits.

Mycotoxins in Tea: Occurrence, Methods of Determination and Risk Evaluation

“…Despite not being “up to date”, FLD provide sufficiently sensitive, selective, and low-cost detection of aflatoxins and ochratoxin A. Multi-mycotoxin analysis supposes applying of MS/MS technology: dozens of mycotoxins can be determined in a single run [ 32 , 38 ]. The current trend is the multi-class detection of food contaminants, such as mycotoxins and pesticides [ 57 , 58 ], or mycotoxins, pesticides, packaging, and process-induced contaminants [ 60 ] by HRMS/MS technique. The latter research, being not very successful in mycotoxins′ detection, is also worth paying attention to due to the thorough analysis of parameters affecting method performance.…”

“…Tea exhibits the strongest matrix effect, which manifests itself, in a changing fragmentation pattern of mycotoxin ochratoxin A [ 58 ]. Matrix effect can be accounted for by such major co-extracts as polyphenols, caffeine, and amino acids [ 60 ]. For example, the average caffeine content in tea is about 3.5% [ 62 ], that exceeds a minor contaminate concentration (e.g., 10 µg/kg) by over 10 6 times.…”

“…For example, the average caffeine content in tea is about 3.5% [ 62 ], that exceeds a minor contaminate concentration (e.g., 10 µg/kg) by over 10 6 times. Matrix-matched calibrations [ 38 , 60 ] or internal standards [ 35 ] are usually used to overcome the problem.…”

“…Few studies were focused on tea brew analysis for the reason of mycotoxin transfer estimation [ 16 , 39 , 46 ] or analytical method development [ 35 , 38 , 60 ]. Mycotoxin extraction from brewing was carried out by means of IAC (ochratoxin A targeted analysis) [ 28 , 39 ] or dispersive liquid-liquid microextraction (16 mycotoxins, recovery from 66% to 127%) [ 38 ] or liquid-liquid extraction and “dilute and shoot” approach (proved to be suitable for ochratoxin A detection) [ 60 ].…”

Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review

“…Specifically, chlorpyrifos, bifenthrin, lambda-cyhalothrin, cypermethrin, imidacloprid, and acetamiprid were frequently detected pesticides in tea [215,218]. Despite of the fact that the detection rates of pesticides in tea were relatively high, most of the investigated pesticides were below the Chinese and European Union maximum residue levels (MRLs) [25,215]. However, in one study, 39 out of 233 tested tea samples were found to exceed European Union MRLs, and bifenthrin had the highest detection rate [217].…”