Procedures for determination of metronidazole, ronidazole and dimetridazole residues in honey

16.
2.
2.
6 Determination

(1) Liquid chromatography conditions

Chromatographic column: Atlantis dC ₁₈ , 3um, 150mm×2.
1mm (inner diameter) or equivalent; mobile phase: acetonitrile +0.
1% formic acid water (30+70); flow rate: 200μL/min; column temperature: 30°C; sample volume : 20μL
.

(2) Mass spectrometry conditions

Ion source: Electrospray ion source (ESI); Scan mode: Positive ion scan; Detection mode: Multi-reaction monitoring; Electrospray voltage: 5500V; Atomizing gas pressure: 0.
069MPa; Curtain gas pressure: 0.
069MPa; Auxiliary gas flow rate: 6L/min; ion source temperature: 700℃; qualitative ion pair, quantitative ion pair, declustering voltage and collision energy are shown in Table 16-10
.

Table 16-10 Mass spectrometric parameters of three nitroimidazole drugs

(3) Liquid chromatography-tandem mass spectrometry determination

Under optimum conditions the instrument, with metronidazole , ronidazole , dimetridazole mixed matrix standard working solution each sample peak area as ordinate mixed matrix standard working standard solution at abscissa work Curve, use the standard working curve to quantify the sample, and the response values ​​of metronidazole, ronidazole and dimetridazole in the sample solution should be within the linear range determined by the instrument
.

Figure 16-5 Total ion chromatogram of metronidazole, ronidazole, dimetridazole standard substances