Determination of 9 Penicillin Residues in Livestock and Poultry Meat-Selection of Analysis Conditions (1)

5.
2.
1.
7 Selection of analysis conditions

(1) Selection of solid phase extraction column

In the study of this method, OasisHLB solid phase extraction column, BUNDELUT C ₁₈ solid phase extraction column, ENVI-18 solid phase extraction column, Octadecyl C ₁₈ solid phase extraction column, LiChrolutEN solid phase extraction column and Sep-Pak C ₁₈ solid phase extraction column were used.
A total of six solid phase extraction columns were used to compare the extraction efficiency and purification effects of nine penicillins
.

(2) Selection of extraction solution

Deionized water, 4% sodium chloride solution and sodium dihydrogen phosphate buffer solution (0.
15 mol/L, pH 8.
5) were used as extraction solutions to complete the recovery rate experiment of 9 penicillins in the sample
.

Because the concentration and pH of the sodium dihydrogen phosphate buffer solution have a greater impact on the recovery rates of amoxicillin and ampicillin, the buffer solutions of sodium dihydrogen phosphate with different concentrations of 0.
033～0.
2mol/L and the pH of 0.
15mol/L are respectively prepared at 3.
0～0.
2mol/L.
9.
5 Sodium dihydrogen phosphate buffer solution, complete the recovery rate experiment of amoxicillin and ampicillin, the results are shown in Table 5-8
.

Table 5-7 The influence of three extracts on the recovery rate of 9 penicillins

Table 5-8 The influence of different concentration and pH of sodium dihydrogen phosphate buffer solution on the recovery rate of amoxicillin and ampicillin

(3) Selection of elution conditions for solid phase extraction column

This method compares the effect of using 1mL, 2mL, 3mL, 4mL acetonitrile -water (1+1, v/v) as the eluent of the solid phase extraction column on the recovery rate of 9 penicillins.

Table 5-9 The effect of solid phase extraction column eluent dosage on recovery rate (%)