The application discloses a method for determining the content of DMPP in compound
fertilizer, comprising the following steps: S1, standard working solution preparation; S2, sample pretreatment; S3,
chromatography-
mass spectrometry detection; S4, quantitative analysis. In view of the quantitative error caused by the matrix effect, the application proposes to prepare a gradient standard working solution by using a blank
fertilizer matrix extract, to eliminate the physical and
chemical property difference between the sample and the
standard product through matrix matching, and to improve the accuracy of the
calibration curve. Secondly, in order to strengthen the purification effect of the
complex matrix sample, a C18
solid-phase extraction column is introduced to combine with a
methanol-water
system for
elution, and the activation and redissolution conditions are optimized, so that the non-polar interferents such as lipids and pigments are effectively removed, the NY / T3423-2019
water extraction system is compatible, the ESI + / MRM mode is adopted, and the sensitivity and anti-interference ability are significantly better than those of HPLC-UV; the method is suitable for research / internal control / confirmation, and if used for supervision sampling / arbitration, method
verification and recognition need to be completed in advance.