Confirmation of avermectin residues in food matrices with negative-ion atmospheric pressure chemical ionization liquid chromatography/mass spectrometry

Abstract

A multi-residue LC/MS method has been developed to confirm avermectin drug residues in several food matrices. Ivermectin (IVR), doramectin (DOR), eprinomectin (EPR) and moxidectin (MOX) are confirmed using atmospheric pressure chemical ionization (APCI) with negative ion detection and selected ion monitoring of three to four ions for each compound. The drug residues are extracted from tissue or milk using previously published procedures. IVR and DOR are confirmed at 20 ppb levels in fortified salmon muscle; IVR is also confirmed in tissue from salmon dosed with the drug. Residues of DOR, IVR, and EPR are confirmed in fortified milk at the 20 ppb level and in fortified beef liver at 40 ppb. Residues of MOX can also be confirmed in these matrices, but at slightly higher levels (40-80 ppb).

Positive and negative electrospray LC–MS–MS methods for quantitation of the antiparasitic endectocide drugs, abamectin, doramectin, emamectin, eprinomectin, ivermectin, moxidectin and selamectin in milk

“…Similarly Wu et al [15], observed the formation of the [M + Na] + , [M + K] + adducts and observed that it was difficult to obtain correct results when Na + and K + were present. Finally in many of the methods in which positive ion MS was used for confirmation, it appears that quantitation was undertaken using LC with fluorescence detection as there is no mention of the linearity of the MS method ( [10,14,16,18]. Because of this nonlinearity, the positive ion method was initially abandoned and the negative ion method developed.…”

“…To overcome the sodium adduct and linearity problems, several methods have been reported using LC-MS with atmospheric pressure chemical ionization (APCI) with positive ion detection in which either the [M + H] + [12], the [M + NH 4 ] + [16], or fragment [17] ions were monitored. Linear calibration curves were obtained using APCI with negative ion [M − H] − monitoring [15,18,19]. Second order polynomial calibration curves were found to be more appropriate for quantitation using the [M − H] − ions formed by negative ion APCI with a wide range of analyte concentrations.…”

Anthelmintic activity of Ethanolic extract of whole plant of Eupatorium odoratum. L

“…During the past few decades, despite numerous advances made in understanding the mode of transmission and the treatment of these parasites, there are still no efficient products to control certain helminths and the indiscriminate use of some drugs has generated several cases of resistance [2][3][4]. Furthermore, it has been recognized recently that anthelmintic substances having considerable toxicity to human beings are present in foods derived from livestock, posing a serious threat to human health [5,6]. Consequently, the discovery and development of new chemical substances for helminth control is greatly needed and has promoted studies of traditionally used anthelmintic plants, which are generally considered to be very important sources of bioactive substances [7].…”

Determination of malachite green and leucomalachite green in edible goldfish muscle by liquid chromatography–ion trap mass spectrometry

“…Several analytical methods for the determination of MG and LMG in various matrices such as fish tissue [6,[11][12][13] and water [14] have been reported. Highperformance liquid chromatography (HPLC) with UV-vis by post-column oxidation of LMG to MG using lead (IV) oxide [11] or with electrochemical detection [12] has been commonly used for the determination of MG and LMG.…”