Determination of 5 Cephalosporins Residues in Honey——Linear Range and Lower Limit of Determination

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5.
8 Linearity range and lower limit of determination

Prepare sample matrix mixed standard solutions (0.
5-40 LOD) containing cefpirin, cephalexin , ceflonine, cefquinoxime, and cefazolin at a concentration of 2.
5～1000ng/mL respectively, and measure under selected conditions.
the injection volume was 20 L, with the peak area was plotted against the concentration of each test standard components, cefazolin, cephapirin , cephalexin, CTP, the absolute amount of cefquinome are in the range of 0.
05 ~ 20ng All of them are in a linear relationship and meet the quantitative requirements.
The linear equations and correction factors are shown in Table 5-40
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Table 5-40 Linear equations and correction factors of 5 cephalosporins

Under the operating conditions of this method, when the 5 cephalosporins were added at a level of 2-100μg/kg (LOD-10LOD), their respective measured response values ​​were within the linear range of the instrument
.

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9 Method recovery and precision

Use samples that do not contain 5 cephalosporins to perform addition recovery and precision experiments.
After adding 4 different levels of 5 cephalosporin standards at 2-100μg/kg (LOD～10 LOD) to the sample, shake well to make The standard substance and the sample are fully absorbed, and then extracted and purified according to this method, and measured with a high performance liquid chromatography-tandem mass spectrometer.
The recovery rate and precision are shown in Table 5-41
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Table 5-41 Experimental data of recovery rate of 5 kinds of cephalosporins (n=10)

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10 Applicability of the method

This method is used to treat twelve honey species of rape honey, linden honey, wattle honey, acacia honey, sunflower honey, buckwheat honey, date nectar, alfalfa honey, codonopsis honey, schisandra honey, and astragalus honey.
～100μg/kg (LOD～10 LOD) Four different levels of 5 cephalosporins were added to the recovery rate experiment to check the applicability of the method.
The analysis results are shown in Table 5-42, which can be seen from Table 5-42.
The recoveries of five cephalosporins at four levels of twelve honey species were between 80.
2% and 107.
8%, and the relative standard deviations were between 2.
82% and 10.
56%, indicating that the method has good applicability
.

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11 Repeatability and reproducibility

Under repeatability test conditions, the absolute difference between the two independent test results obtained does not exceed the repeatability limit (r).
If the difference exceeds the repeatability limit (r), the test results should be discarded and the two individual tests should be completed again.
Determination
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Table 5-42 The experimental data of the recovery rate of 5 kinds of cephalosporins of different honey species (n=10)

Table 5-43 The content range of 5 cephalosporins and their repeatability and reproducibility limits