Simultaneous Determination of Emamectin, its Metabolites, Milbemectin, Ivermectin and Abamectin in Tomato, Japanese Radish and Tea by LC/MS

Abstract

We developed a simple and rapid analytical method for determining the residues of emamectin benzoate, milbemectin, abamectin, ivermectin and emamectin metabolites in tomato, Japanese Radish and Japanese tea by liquid chromatography/mass spectrometer (LC/MS) with electrospray ionization (ESI). A sample extracted with acetone was simply cleaned up using only a Sep-Pak C18, and then directly measured by LC/MS (ESI). Several LC/ MS measurement conditions were studied that included the mobile phase, solvent for sample solution, range of calibration and standard deviation of the measurement. Detecting target macrocyclic lactone chemicals with methanol as the mobile phase was more sensitive than acetonitrile, especially, milbemectin. The detection limits of these chemicals were 0.1 to 0.5 ng/ml (10 µl injection), and they were similar or more sensitive to the previous fluorescence detection method. For the measurement of these chemicals in tomato, Japanese radish and tea by LC/MS (ESI), ion suppression was always observed. To compensate for such an effect, we used a matrix-matched calibration. This compensation method is effective for obtaining accurate values. The recoveries by the developed method were in an acceptable range for the screening method and 90.1-120.9% except for milbemectin and abamectin from tea leaves that had interfering peaks.

Residue Analysis of Difenoconazole, Emamectin Benzoate and Fenazaquin on Tomatoes Using High Pressure Liquid Chromatography

“…The present study also indicates that the residues of emamectin benzoate on tomatoes were rapidly decreased. These results are supported by Yoshii, et al, (2001Yoshii, et al, ( & 2004 who determined the residues of emamectin and its metabolites, in tomato and Japanese radish by liquid chromatography, and found that emamectin rapidly degraded to its metabolites.…”

“…Emamectin benzoate is semi-synthetic derivative from abamectin (Prabhu, et al, 1991). It is registered as an acaricide for different food commodities in different countries (Yoshii, et al, 2004).…”

“…Kmell?r, et al, (2008) carried out a validation study on tomato by using a rapid and sensitive liquid chromatographic method for the determination of 160 selected multi-class pesticides including the tested pesticides. Also, Liquid chromatography was reported for determining emamectin (Yoshii, et al, 2001(Yoshii, et al, & 2004, fenazaquin (Kumar, et al, 2006) and certain pesticide residues in vegetables (Khan, et al, 2009).…”

Estimation of Abamectin Residues Present in Tea: High-Performance Liquid Chromatography Technique

“…Because of its high toxicity to agricultural pests abamectin is widely used to control insects and mites in tea, vegetables, and fruits [3]. Abamectin present in various biological matrices including animal tissues, serum, fruits, and vegetables can be successfully determined by high-performance liquid chromatography (HPLC) in the reverse phase mode, coupled with different detectors, namely, ultraviolet detection (UVD), fluorescence detection (FLD), and mass spectrometry (MS) [3][4][5]. However, there is no report in the literature on the methodology for the determination of abamectin residues present in tea.…”

Development of an extraction method for the determination of avermectins in soil using supercritical CO2 modified with ethanol and liquid chromatography‐tandem mass spectrometry

“…The low stability of the derivatized samples led to a decrease in the reproducibility of the result, and derivatization reagents produced by‐products that can reduce the lifetime of the chromatographic column. On the other hand, MS) was able to detect avermectins in environmental and food samples with high sensitivity and without derivatization .…”