Pesticide determination in rose petals using dispersive solid-phase extraction followed by gas chromatography-tandem mass spectrometry

A review on pesticides in flower production: A push to reduce human exposure and environmental contamination

In several countries, flower import regulations are restricted to food security, by establishing maximum residue limits (MRL) for pesticides in flower-based food products and biosafety, in order to limit the circulation of vectors, pests and exotic species across borders. In this context, the lack of limits on pesticides in flower-products for ornamental purposes can influence the pesticide overuse in production areas, as well as the transfer of contaminated products between countries. Therefore, the purpose of this review was to discuss possible adverse effects on human and environmental health of pesticides used in floriculture, evaluating regulations on the use of these pesticides in the main importing and flower-producing countries. This review included 92 documents. The use of 201 compounds was identified by interviews and analytical measurements. Among them, 93 are banned by the European Union (EU), although 46.3 % of these compounds have been identified in samples from European countries. Latin American countries have a large number of scientific publications on pesticides in flower production (n = 51), while the EU and China have less studies (n = 24) and the United States and Japan have no studies. Regarding adverse health effects, poorer neurobehavioral development, reproductive disorders, congenital malformations and genotoxicity have been reported for residents of flower production areas and workers throughout the flower production cycle. Studies including water samples show overuse of pesticides, while environmental impacts are related to water and air contamination, soil degradation and adverse effects on the reproduction and development of non-target organisms. This review points out that the absence of MRL for non-edible flowers can be crucial for the trade of contaminated products across borders, including pesticides banned in importing countries. Furthermore, setting limits on flowers could reduce the use of pesticides in producing countries.

Human health risk assessment of pesticide residues in honeysuckle samples from different planting bases in China

The buds and initial flowers of honeysuckle (Lonicera japonica Thunb.) are most widely used in traditional Chinese medicines (TCMs). In recent years, the problem of pesticide residues in honeysuckle has attracted much attention. This research aimed to study pesticide residual situation of honeysuckle in China and estimate the potential health risks for consumers using the HQ (hazard quotient) and HI (hazard index) methods. A reliable and robust method was established to determine and quantify 137 pesticide residues simultaneously by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for 151 honeysuckle samples from different planting bases in China in 2017 and 2018. Fifty-four pesticides were detected in total, including 10 unauthorized pesticides (chlorpyrifos, fipronil, carbofuran, omethoate, isofenphos-methyl, triazophos, methomyl, dimethoate, methidathion, and methamidophos). One hundred and fifty (99.3%) samples contained at least 1 and up to 31 pesticides and/or their metabolites, with concentrations ranging from 0.001 to 3.087 mg/kg. Carbendazim, chlorbenzuron, imidacloprid, chlorpyrifos, and acetamiprid were the most frequently detected pesticides in 2017 and 2018, and the corresponding detection rates were 95.31%, 64.06%, 65.63%, 53.13%, 57.81%, and 98.85%, 88.51%, 70.11%, 77.01%, 57.47%, respectively. The acute hazard quotient (HQ_a) of carbofuran was 1.54 for specific population (fetus, infants, and pregnant or nursing women), which indicated that it posed a potential acute health risk. In the cumulative risk assessment, the acute hazard index (HI_a) of insecticides in honesuckle for children and the specific population were 1.34 and 3.36, respectively, suggesting that they posed potential acute cumulative health risks. These results were of theoretical and practical value for evaluating the safety of honeysuckle and improving its quality and safety.

Residue behavior and risk assessment of mixed formulation of imidacloprid and chlorfenapyr in chieh-qua under field conditions

A simple and rapid method based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the simultaneous determination of imidacloprid and chlorfenapyr residues in chieh-qua. Field trials were designed to investigate the dissipation and terminal residue behavior of the mixed formulation of imidacloprid and chlorfenapyr in chieh-qua in Guangzhou and Nanning areas. Risk assessment was performed by calculating the risk quotient (RQ) values. The developed analytical method exhibited recoveries of 89.9-110.3% with relative standard deviations (RSDs) of 2.8-12.5% at the spiked levels of 0.01, 0.10, and 1.00 mg/kg. The limit of detection (LOD) was 0.003 mg/kg, and the limit of quantification (LOQ) was 0.01 mg/kg for both imidacloprid and chlorfenapyr. It was found that the half-lives of imidacloprid in chieh-qua under field conditions were 3.3 and 3.5 days in Guangzhou and Nanning at a dose of 180 g ai/ha, while the half-lives of chlorfenapyr were 3.3 and 2.6 days, respectively. The terminal residues of imidacloprid and chlorfenapyr were from 0.01 to 0.21 mg/kg and from 0.01 to 0.46 mg/kg, respectively. Results of dietary exposure assessment showed that the RQ values were much lower than 1, indicating that the risk of imidacloprid and chlorfenapyr applied in chieh-qua was negligible to human health under recommended dosage and good agricultural practices. The proposed study would provide guidance for safe and reasonable use of imidacloprid and chlorfenapyr in chieh-qua cultivation in China.

Sensitive determination of mixtures of neonicotinoid and fungicide residues in pollen and single bumblebees using a scaled down QuEChERS method for exposure assessment

To accurately estimate exposure of bees to pesticides, analytical methods are needed to enable quantification of nanogram/gram (ng/g) levels of contaminants in small samples of pollen or the individual insects. A modified QuEChERS extraction method coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis was tested to quantify residues of 19 commonly used neonicotinoids and fungicides and the synergist, piperonyl butoxide, in 100 mg samples of pollen and in samples of individual bumblebees (Bombus terrestris). Final recoveries ranged from 71 to 102 % for most compounds with a repeatability of below 20 % for both pollen and bumblebee extracts spiked at 5 and 40 ng/g. The method enables the detection of all compounds at sub-ng/g levels in both matrices and the method detection limits (MDL) ranged from 0.01 to 0.84 ng/g in pollen and 0.01 to 0.96 ng/g in individual bumblebees. Using this method, mixtures of neonicotinoids (thiamethoxam, clothianidin, imidacloprid and thiacloprid) and fungicides (carbendazim, spiroxamine, boscalid, tebuconazole, prochloraz, metconazole, fluoxastrobin, pyraclostrobin and trifloxystrobin) were detected in pollens of field bean, strawberry and raspberry at concentrations ranging from <MDL to 67 ng/g for neonicotinoids and from <MDL to 14 ng/g for fungicides. In bumblebees, the insecticides thiamethoxam and thiacloprid were present at concentrations >MDL, and in some bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations between 0.80 to 30 ng/g. This new method allows the analysis of mixtures of neonicotinoids and fungicides at trace levels in small quantities of pollen and individual bumblebees and thus will facilitate exposure assessment studies.

Behavior of Multiclass Pesticide Residue Concentrations during the Transformation from Rose Petals to Rose Absolute

This study investigates the concentrations of 54 multiclass pesticides during the transformation processes from rose petal to concrete and absolute using roses spiked with pesticides as a model. The concentrations of the pesticides were followed during the process of transforming the spiked rose flowers from an organic field into concrete and then into absolute. The rose flowers, the concrete, and the absolute, as well as their transformation intermediates, were analyzed for pesticide content using gas chromatography/tandem mass spectrometry. We observed that all the pesticides were extracted and concentrated in the absolute, with the exception of three molecules: fenthion, fenamiphos, and phorate. Typical pesticides were found to be concentrated by a factor of 100-300 from the rose flowers to the rose absolute. The observed effect of pesticide enrichment was also studied in roses and their extracts from four classically phytosanitary treated fields. Seventeen pesticides were detected in at least one of the extracts. Like the case for the spiked samples in our model, the pesticides present in the rose flowers from Turkey were concentrated in the absolute. Two pesticides, methidathion and chlorpyrifos, were quantified in the rose flowers at approximately 0.01 and 0.01-0.05 mg kg(-1), respectively, depending on the treated field. The concentrations determined for the corresponding rose absolutes were 4.7 mg kg(-1) for methidathion and 0.65-27.25 mg kg(-1) for chlorpyrifos.