Determination of Levamisole Residues in Milk and Milk Powder

18.

(1) Liquid chromatography conditions

Chromatographic column: BEH C ₁₈ , 50mm×2.

(2) Mass spectrometry conditions

Ionization mode: ESI ⁺ ; Detection method: Multiple reaction monitoring (MRM); Capillary voltage: 2.

Table 18-3 Quantitative ion pair, qualifier ion, and collision energy parameters

(3) Qualitative determination

When the sample solution is determined under the conditions of liquid chromatography-tandem mass spectrometry, if the deviation of the retention time of the detected chromatographic peak and the retention time of levamisole in the standard solution is within ±2.

(4) Quantitative determination

Use the mixed standard working solution to inject the sample, and draw the standard working curve with the concentration of the working solution as the abscissa and the peak area as the ordinate

Figure 18-2 Multiple reaction monitoring (MRM) chromatogram of levamisole reference material

Related Links: Determination of Levamisole Residues in Milk and Milk Powder by Liquid Chromatography-Tandem Mass Spectrometry