Determination of Ethyl Carbamate in Commercial Sweetened Sugar Cane Spirit by ESI-MS/MS Using Modified QuEChERS and 18-Crown-6/Trifluoroacetic Acid Spiking Additives

A fast, sensitive, and selective direct injection electrospray tandem mass spectrometry (DI‑ESI‑MS/MS) method that is able to quantify ethyl carbamate in commercial sweetened sugar cane spirit is described. The preparation method uses a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) with potassium carbonate added to sweetened sugar cane spirit to separate the aqueous phase from the ethanol phase. The aqueous phase contains sucrose that suppresses electrospray ionization. Ethyl carbamate supernatant from the ethanol phase is transferred and enriched with 18-crown-6/trifluoroacetic acid additives. The additives sequester metal cations reducing the ionization of sodium and potassium, favoring the detection of ethyl carbamate as sole protonated cations. The method was successfully applied for the quantification of eleven real samples and certified sugar cane spirit demonstrating its applicability for quality control and regulatory analysis. The method showed reliable analytical parameters compared to conventional gas chromatography mass spectrometry (GC-MS) method commonly used for ethyl carbamate analysis. DI-ESI-MS/MS method requires just a fast step sample clean up and presents consistent values for the limit of detection (LOD 48.0 μg L−1) and limit of quantification (LOQ 160.0 μg L−1). Furthermore, the recoveries obtained were close to 100%, with relative standard deviations below 10% of sample certificates.

Fipronil and Fipronil Sulfone Distribution in Chicken Feathers and Eggs after Oral and Dermal Exposure

This work aimed to investigate the bio-distribution and the persistence of fipronil and its primary metabolite fipronil sulfone after oral and dermal administration by simulating natural farming conditions. Fipronil and fipronil sulfone detection and quantification were performed in different poultry matrices using an LC-MS/MS method coupled with modified QuEChERS extraction. After oral administration, fipronil was detected in feathers at each sampling time, in eggs for 28 days, and in the internal organs at the end of the experiment. After dermal administration, high levels of fipronil were detected in feathers, accounting for 195.85 ± 8.54 mg/kg, which were reduced by a third after 60 days. No traces of fipronil were detected in the eggs or internal organs. In addition, fipronil sulfone showed remarkable residues in all samples in trial 2. The data obtained confirmed that inappropriate use of unauthorized pesticides can lead to severe contamination of entire poultry farms. The contemporary presence of fipronil sulfone in feathers and eggs associated with the lack of fipronil in eggs suggests recent dermal contamination or past oral contamination. Moreover, simultaneous analysis of hens’ feathers and eggs could represent a new method to improve large-scale monitoring programs and animal welfare, limiting their slaughter.

Τemporal Variation in Pesticide Residues in Citrus Fruits from Chios, Greece, before and after the Development of an Integrated Pest Management Strategy (IPMS): A Five-Year Study (LIFE13 ENV GR/000414)

The temporal variation in pesticide residues in Kampos, of Chios Island, in Greece, was determined between June 2014 and October 2019. Monitoring of residues took place before and after the development of an Integrated Pest Management Strategy (IPMS) for the sustainable control of the Mediterranean fruit fly (medfly) based on mass trapping with the non-toxic and environmentally friendly attractant Biodelear. A total of 1252 samples of citrus fruits, collected from 12 experimental citrus orchards, were analyzed for the presence of 353 active substances and metabolites of pesticides. A modified QuEChERS method and sensitive chromatographic techniques were used. During preparatory monitoring for the project, the most frequently detected pesticides were the insecticides chlorpyrifos, deltamethrin and spirotetramat; the fungicides propamocarb, dimethomorph and mepanipyrim; and the synergist piperonyl butoxide. The implementation of the IPMS to address medfly resulted in a dramatic reduction in the pesticides detected in citrus fruits during confirmatory monitoring, with no detectable residues—which may cause serious problems to human health—in any of the samples analyzed at the end of the project, thus enhancing consumer safety.

Determination and Dietary Intake Risk Assessment of 35 Pesticide Residues in Cowpea (Vigna Unguiculata L. Walp) from Hainan Province, China

The presence of pesticide residues in cowpea raises serious health concerns. In this study, a novel, sensitive, high-performance method was developed to simultaneously analyse the residues of 35 pesticides in cowpea samples from growing areas in Hainan provinces of China, from November in 2018 and June in 2021, using modified QuEChERS sample pretreatment coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS). The limits of detection (LOD) and quantification (LOQ) values of 35 pesticides in the cowpea matrix ranged from 0.3 µg/kg to 2.5 µg/kg and 1.0 µg/kg to 8.0 µg/kg, respectively. Twenty-seven different pesticides were detected, and twelve of them were banned pesticides on legumes in China. Residues for ten pesticides in 17.1% of the samples exceeded their MRLs with the highest exceedance of 380%, 80.8% of samples contained one or more pesticide residues, and the most frequently detected pesticide was chlorfenapyr with a detection rate of 46.3%. In addition, the pesticide triazophos was detected through different years and regions. Furthermore, the chronic dietary exposure risk (%ADI) of the detected pesticides showed less than 100% in Chinese people of different age groups, which was evaluated by the national estimated acceptable daily intake.