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Anthraquinone (AQ) levels in some Indonesian dried tea leaves samples from different plantation areas and their brewed tea samples were determined by gas chromatography–tandem mass spectrometry methods. The mean lower bound, middle bound, and upper bound of AQ levels in 59 dried tea leaves samples were 82.2, 82.8, and 83.4 μg/kg, respectively, while their 95%th percentile values were identical at 190.3 μg/kg (0.1903 mg/kg). In a transfer rate study, the mean and 95%th AQ levels in 30 dried tea leaves samples with AQ level ≥ LOQ (limit of quantification) were 128.6 and 194.5 μg/kg (0.1945 mg/kg), while those of their corresponding brewed tea samples were 2.1 and 3.4 μg/kg, respectively. The mean and 95%th transfer rates of AQ into brewed tea samples were 51.99 and 88.17%. Using these data and taking into account daily tea consumption, calculated cancer potency slope factor, benchmark dose of 10% effect at lower bound 95% confidence interval of AQ, and average body weight, the risk characterization due to exposure to this compound from tea consumption was calculated and stated as incremental lifetime cancer risk (ILCR) and margin of exposure (MOE). The overall results revealed that AQ levels in dried tea leaves up to the highest level found in the samples lead to an ILCR of not more than 10 –6 and an MOE of not less than 10 4 and hence was predicted to give sufficient consumer protection.

Abstract.A method using QuEChERS sample preparation followed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was developed for quantitative determination of 14 pesticide residues in Indonesian green coffee beans. The European Standard Method EN 15662:2008 was modified to obtain an appropriate extraction and clean-up procedure for green coffee bean samples. Homogenous slurry samples were extracted with 1% acetic acid in acetonitrile and the extracts were cleaned up by a high pigment dispersive SPE. LC-ESI-MS/MS was operated in the MRM mode for two specific precursor-product ion transitions per target compound to obtain 4 identification points. Rrepresentative matrix-matched calibration curves were applied to compensate matrix effects. This method was validated according to the requirements of SANCO/12495/2011. Limits of detection (LODs) and limits of quantification (LOQs) were obtained in the ranges of 0.2-2.9 µg kg -1 and 0.8-9.7 µg kg -1 respectively, showing lower values than the maximum residu limits (MRLs) set by importing countries. The method was applied to determine 14 pesticide residues in 181 Indonesian green coffee bean samples that were taken from different regions. Some pesticide residues were found in these samples and detected to be higher than the MRLs.

The first proficiency testing of pesticides in fruits and vegetables in Indonesia is reported. This report covers the findings of five-year proficiency testings. Every year, from 2016 to 2020, 18–25 laboratories join the proficiency testings and analyze 5–11 pesticides in tomato, orange, lettuce, brown rice, strawberry respectively. The number of laboratories participating in the proficiency testings tends to increase, although only 38 % of the laboratories are able to report all pesticides. More than 72 % of participants use QuEChERS or its modifications for sample preparation, all participants use gas chromatography or liquid chromatography for separation, at least 20 % of participants still rely on detectors other than mass spectrophotometer for detection, and 20 %–60 % of participants use matrix-matched calibration for quantification. The performance of laboratories is evaluated as z -score with an average of 90.8 % achieves satisfactory results while 3.3 % and 5.9 % achieve questionable and unsatisfactory results correspondingly. Overall, the performance of laboratory participants during proficiency testings is good. However, improvement is still needed, especially for the number of target pesticides for multi-residue pesticide analysis. Moreover, unsatisfactory z -scores are likely to be resulted from laboratories which use conventional solvent extraction, use detectors other than mass spectrometers, and are not accredited.

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