echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Chemicals Industry > Chemical Technology > The linear range and lower limit of determination of 7 quinolones residues in milk and milk powder

    The linear range and lower limit of determination of 7 quinolones residues in milk and milk powder

    • Last Update: 2021-09-19
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com

    11.
    2.
    3.
    8 Linearity range and lower limit of determination

    According to the sensitivity of 7 kinds of quinolone drugs, a series of matrix standard working solutions were prepared with sample blank solution and measured under selected chromatographic conditions and mass spectrometry conditions.
    The injection volume was 15uL, and the peak area was used to measure the matrix standard working solution.
    The concentration of the components is plotted, and the linear range, linear equation and linear correlation coefficient are shown in Table 11-21
    .


    This method uses matrix addition standards to calibrate the content of the sample to eliminate matrix interference


    Table 11-2 The linear ranges, linear equations and correlation coefficients of 17 quinolones

    Thus, in the process operating conditions, marbofloxacin , ciprofloxacin , enrofloxacin , danofloxacin , orbifloxacin , difloxacin and the quinolone seven sarafloxacin 1 ~ 50ng/mL (corresponding to the quinolone drug residue in milk within the range of 0.
    5-25.
    0μg/kg, corresponding to the quinolone drug residue in the milk powder within the range of 2.
    0-100.
    0μg/kg), the response values ​​are all within the linear range of the instrument
    .


    At the same time, the limit of detection (LOD) of 7 quinolones in milk is 0.


    11.
    2.
    3.
    9 Method recovery and precision

    Use milk and milk powder samples that do not contain the 7 quinolones to be tested for addition recovery and precision experiments.
    After adding different concentration standards to the samples, they are placed for 1 hour to allow the standards to be fully absorbed by the sample, and then extraction and purification are carried out according to this method.
    Measured by liquid chromatography-tandem quadrupole mass spectrometry, the recovery and precision results are shown in Table 11-22 and Table 11-23
    .


    The recovery rate of milk in this method is between 83.


    Table 11-22 The recovery rate and precision experimental data of 7 quinolones in milk

    Table 11-23 The recovery rate and precision experimental data of 7 quinolones in milk powder

    11.


    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 11-24 Content range and repeatability and reproducibility equation of 7 quinolones in milk


    Table 11-25 Content range and repeatability and reproducibility equation of 7 quinolones in milk powder


     

     

    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.