Studies On The Rapid Determination Of Hormones In Milk By Chromatography-mass Spectrometry

China’s current processing dairy and dairy products quality is not optimistic, since illegally added melamine in milk powder sensation of2008events, the whole society to unprecedented attention to the quality of dairy products to detect, due to the lack of effective control and inspection techniques, the quality and safety of dairy products has occurred frequently, these events seriously hurt consumer trust in the safety of dairy products. The aim of this paper is to develop gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry method for the determination of hormones residues in milk. in milk. It includes three chapters as follows:1、The essential knowledge of hormones was summarized briefly. Besides, the research status of compartment analysis methods in recent years were reviewed.2、A quick confirmative method was developed for determining residues of13glucocorticoids in milk by liquid chromatography-tandem quadrupole mass spectromrtey (LC/MS/MS).The sample was extracted with methyl alcohol at first. Identification of the glucocorticoids was done using retention times and the distribution of diagnostic ion pairs. Quantification of the glucocorticoids was based on the peak areas of the parention and a fragment ion with a higher signal. The limits of quantification (LOQ) of ranged were from0.12to1.12μg/kg, Average recoveries for the13glucocorticoids(spiked at the levels of0.5and2μg/kg)ranged from72.8%to102.6%, with relative standard deviations between6.4%to13.1%0.5μg/kg and2μg/kg. Routine tests showed that the method is fast,sensitive and specific for the determination of glucocorticoids residues in milk.3、The analysis method of determination9kinds of hormones drug residual via gas chromatography mass spectrometry (GC/MS) was fabricated in this chapter. The sample firstly enzymatic hydrolyzed through β-glucuronidase, and then extracted by ethyl acetate. The water in the sample was removed with anhydrous soduim sulfate afterwards. Finaly, the sample was separated by weak polarity chromatography column (HP-5MS (0.25mm×30m×0.25μm)) without derivatization. The effective separation of9kinds of hormones has been realized via selective ion monitoring (SIM) measurement and temperature program optimization. The experimental results indicated that the limit of detection (S/N≥10) was0.5to1.4μg/mL During the linear range from0.5to50μg/mL, the recovery of standard addition was76.1-91.3%with the relative standard deviation (RSD) of2.8～14.6%. The proposed analysis method is simple and rapid with accurate result. Consequently, it would be intended as a rapid determination approach of hormone residue in liquid milk product.