Rapid detection method for melamine and sulbactam in liquid milk

Abstract

The invention relates to a rapid detection method for melamine and sulbactam in liquid milk, and belongs to the technical field of liquid milk analysis. In the rapid detection method, a sample is extracted through an acetic acid water solution, subjected to protein sedimentation through acetonitrile and diluted, Acquity UPLC BEH HILIC(100*2.1mm, i.d., particle diameter of 1.7 micrometers) separation is carried out, and electrospray ion source multi-reaction monitoring (MRM) mode tandem mass spectrum measurement is carried out. An extracting solvent, extracting time, purifying time, instrument measurement conditions and the like are optimized. Results prove that melamine and sulbactam have the good linear relation within the range of 0.02-20 ng / mL and 0.05-100 ng / mL respectively, and the correlation coefficient is larger than 0.99. In the high, middle and low addition levels, the recovery rate of practical samples is between 82.5% and 103.5%, the relative standard deviation (RSD n=6) is between 0.9% and 5.1%, and the method quantification limit of melamine and sulbactam is 10 micrograms per kilogram and 1.0 microgram per kilogram respectively. Pretreatment operation is simple and rapid, hydrophilic interaction chromatography-tandem mass spectrometry detection sensitivity is high, and qualitative and quantitative operation is accurate.

Description

technical field [0001] The invention relates to a rapid detection method for melamine and sulbactam in liquid milk, belonging to the technical field of liquid milk analysis. Background technique [0002] The scientific name of melamine is triaminetriazine, also known as melamine. It is an important nitrogen-containing heterocyclic organic chemical raw material. It is a white crystalline powder and tasteless. It is often used in the production of plastics, glue, flame retardants and fertilizers. Protein is mainly composed of amino acids, and its nitrogen content generally does not exceed 30%, while the molecular formula of melamine contains about 66% nitrogen. The general protein testing method Kjeldahl method is to estimate the protein content by measuring the nitrogen content, therefore, the addition of melamine will make the protein test content in liquid milk too high. Long-term intake of melamine can cause reproductive and urinary system damage, bladder and kidney stone...

AI Technical Summary

Problems solved by technology

The three methods all use solid-phase extraction columns to purify the samples, the operation steps are relatively cumbersome, and the pretreatment time is long

The detection methods for antibiotic residues are becoming more and more perfect, so some criminals add β-lactamase (β-lactamase) to milk in order to evade the detection of antibiotics, which can degrade β-lactam antibiotics such as commonly used penicillin and make microorganisms Conventional detection methods such as ELISA and enzyme-linked immunoassay are ineffective, so it is impossible to correctly judge whether it is "anti-antibiotic-free milk", covering up the fact that antibiotics exceed the standard

However, sulbactam irreversibly binds to β-lactamase, reducing or even zeroing the free enzyme in the solution, which cannot be effectively detected by existing methods, and condones the abuse of antibiotics and the illegal addition of non-edible substance β-lactamase Behavior that seriously threatens the health of consumers

[0008] Since 2011, sulbactam has been included in the national risk monitoring project, but no national standard has been issued so far

Therefore, melamine and sulbactam in liquid milk often need to be tested at the same time, and the existing detection method needs to be tested twice to complete

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