Acaricide Residues in Honey: Analytical Methods and Levels Found

Development and validation of modified QuEChERS method coupled with LC-MS/MS for simultaneous determination of cymiazole, fipronil, coumaphos, fluvalinate, amitraz, and its metabolite in various types of honey and royal jelly

Over the past few decades, honey products have been polluted by different contaminants, such as pesticides, which are widely applied in agriculture. In this work, a modified EN - quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method was developed for the simultaneous quantification of pesticide residues, including cymiazole, fipronil, coumaphos, fluvalinate, amitraz, and its metabolite 2,4-dimethylaniline (2,4-DMA), in four types of honey (acacia, wild, chestnut, and manuka) and royal jelly. Samples were buffered with 0.2M dibasic sodium phosphate (pH 9), and subsequently, acetonitrile was employed as the extraction solvent. A combination of primary secondary amine (PSA) and C18 sorbents was used for purification prior to liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI⁺/MS-MS) analysis. The estimated linearity measured at six concentration levels presented good correlation coefficients (R²)≥0.99. The recovery, calculated from three different spiking levels, was 62.06-108.79% in honey and 67.58-106.34% in royal jelly, with an RSD<12% for all the tested compounds. The matrix effect was also evaluated, and most of the analytes presented signal enhancement. The limits of quantification (LOQ) ranged between 0.001 and 0.005mg/kg in various samples. These are considerably lower than the maximum residue limits (MRL) set by various regulatory authorities. A total of 43 market (domestic and imported) samples were assayed for method application. Among the tested samples, three samples were tested positive (i.e. detected and quantified) only for cymiazole residues. The residues in the rest of the samples were detected but not quantified. We concluded that the protocol developed in this work is simple and versatile for the routine quantification of cymiazole, 2,4-DMA, fipronil, coumaphos, amitraz, and fluvalinate in various types of honey and royal jelly.

Evaluation of genotoxic effects of Apitol® (cymiazole hydrochloride) in vitro by measurement of sister chromatid exchange

Apitol, with cymiazole hydrochloride as the active ingredient, is used in bee-keeping against the ectoparasitic mite Varroa destructor. The preparation was evaluated for genotoxicity in cultured human peripheral blood lymphocytes. Sister chromatid exchange, the mitotic index and the cell proliferation index were determined for three experimental concentrations of Apitol (0.001, 0.01 and 0.1 mg/ml). All concentrations significantly (p < 0.001) increased the mitotic index (MI = 7.35+/-0.18%, 8.31+/-0.20% and 12.33+/-0.25%, respectively), the proliferative index (PI = 1.83+/-0.01, 1.84+/-0.01 and 1.88+/-0.02, respectively) and the frequency of sister chromatid exchange (SCE = 8.19+/-1.81, 8.78+/-1.80 and 13.46+/-1.88, respectively), suggesting that cymiazole hydrochloride has genotoxic potential.

Determination of acaricides in honey by high-performance liquid chromatography with photodiode array detection

Rapid analytical methods are described to control quality of honeys, concerning residues of acaricides applied in hives to prevent Varroa jacobsoni infestation. A liquid-liquid extraction with hexane-propanol-2-ammonia (60 ml:30 ml:0.28%) was used for the simultaneous analysis of coumaphos, bromopropylate, amitraz and fluvalinate. For thymol, one clean up on a solid-phase extraction C18 (500 mg, 6 ml) column was performed; for rotenone, a liquid extraction with dichloromethane was realised. Quantitative recoveries obtained with honey were satisfactory and were superior to 80%. All acaricides are identified by reversed-phase high-performance liquid chromatography with photodiode array detection. Quantification limits obtained were below maximal residue limits when these exist.

Study of an accelerated solvent extraction procedure for the determination of acaricide residues in honey by high-performance liquid chromatography-diode array detector

An accelerated solvent extraction (ASE) procedure has been optimized for the determination of synthetic acaricides (amitraz, bromopropylate, cymiazole, coumaphos, T-fluvalinate, and flumethrin) and their residues in honey by reversed-phase high-performance liquid chromatography. The effects of experimental variables such as solvent composition, temperature, static extraction time, and solvent flush volume on the ASE efficiency have been studied. The acaricides were extracted by hexane-propanol (1/3, vol/vol) at 95 degrees C and 2.000 psi for 8 min. Recovery values of between 53 and 108% were achieved with the different substances, with coefficients of variation between 2 and 13% and limits of detection from 0.01 to 0.2 microg/g.