echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Chemicals Industry > Chemical Technology > Determination of 9 kinds of penicillin residues in milk and milk powder-linear range and lower limit of determination

    Determination of 9 kinds of penicillin residues in milk and milk powder-linear range and lower limit of determination

    • Last Update: 2021-09-20
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com

    5.
    2.
    2.
    8 Linearity range and lower limit of determination

    According to the sensitivity of each penicillin drug, a series of standard working solutions are prepared with water, and a series of matrix standard working solutions are prepared with the blank solutions of milk and milk powder samples.
    The determination is carried out under the selected chromatographic conditions and mass spectrometry conditions.
    The injection volume is 15μL.
    , Use the ratio of the peak area of ​​the analyte to the peak area of ​​the selected internal standard to plot the concentration of the measured component in the matrix standard working solution.
    The linear range, linear equation and linear correlation coefficient are shown in Table 5-16
    .


    From the linear equations of different matrices, it can be known that the matrix has a certain interference to the determination of the analyte.


    Table 5-16 Linear equations and correction factors of 9 penicillins

    Under the operating conditions of this method, when the added level of 9 penicillins was in the range of 1 to 320 μg/kg, the respective measured response values ​​were within the linear range of the instrument
    .


    The concentration of ampicillin and nafcillin in milk is 1μg/kg, the concentration of amoxicillin, piperacillin , penicillin G, penicillin V, and cloxacillin is 2μg/kg, and the concentration of oxacillin and dicloxacillin is 4ug.


    5.
    2.
    2.
    9 Method recovery and precision

    This method uses penicillin-free milk and milk powder to add a mixed standard solution for recovery and precision tests.
    Four levels are added, and each level is measured 10 times.
    The average recovery and coefficient of variation are shown in Table 5-17
    .


    It can be seen from Table 5-17 that the recovery rate of the milk sample in this method is between 62.


    Table 5-17 Recovery rate and precision data of 9 penicillins in milk and milk powder (n=10)

    5.


    2.
    2.


    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
    .


    Under the reproducibility test conditions, the absolute difference between the two independent test results obtained does not exceed the reproducibility limit (R)


    Table 5-18 Concentrations and repeatability and reproducibility equations of 9 penicillins in milk


    Table 5-19 Concentrations and repeatability and reproducibility equations of 9 penicillins in milk powder

    Related Links: Determination of 9 Penicillin Residues in Milk and Milk Powder-Selection of Analysis Conditions

     

     

    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.