Capillary electrophoresis online enrichment method for sensitively detecting melamine in multiple samples

A technology of capillary electrophoresis and melamine, which is applied in the field of analysis and detection, can solve problems such as low detection sensitivity, and achieve the effects of low analysis cost, environmental friendliness, and overcoming interference.

CN102121919AInactive Publication Date: 2011-07-13JIANGNAN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2011-07-13
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention belongs to the technical field of analytic detection and discloses a capillary electrophoresis method for sensitively detecting melamine in multiple samples. In the method, the melamine is detected through two online enrichment technologies (cation-selective exhaustive injection and micelle sweeping) which are combined, so the enrichment sensitivity of the melamine is improved by 2,600 times and the detection limit is reduced to 1.8mug / kg compared with common capillary zone electrophoresis. Since electric sample introduction of electroosmotic flow is adopted in the method, the method is selective to the sample in a capillary, the influence of a sample matrix is low, a complex sample pre-treating process in method, such as the liquid chromatography and the like, is not required, and the method is suitable for detecting the melamine in multiple samples. The method has high sensitivity; and the detection limit of the method is reduced by two to three levels compared with the detection limits of the conventional liquid chromatography and the conventional fluorescent spectrometry. The used buffer solution is mainly aqueous solution; a great quantity of organic solvent is not required; the pollution is low; and the method is environmentally-friendly. The required solvent and sample are low in using amount and the used hollow capillary is low in price, so the analytic cost is low.
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Description

technical field

[0001] The invention belongs to the technical field of analysis and detection, and discloses a method for detecting melamine in various samples such as milk powder and animal feed by adopting a simple sample pretreatment method combined with capillary electrophoresis on-line enrichment technology. Background technique

[0002] Melamine is an important nitrogen-heterocyclic organic chemical raw material. Since melamine molecules contain a large amount of nitrogen, criminals add melamine to feed and dairy products in order to falsely increase protein content. , eggs and other daily necessities may contain more than the limit value (the limit value in eggs is 2.5mg / kg, the limit value in infant formula milk powder is 1mg / kg, the limit value of melamine in liquid milk, milk powder, and other formula milk powder is 2.5mg / kg). In 2008, more than 51,900 infants and young children in China suffered from urinary diseases due to consumption of formula milk powder con...

Examples

Embodiment Construction

[0020] The present invention will be further described below in conjunction with specific examples.

[0021] The required instruments are: CAPEL105 high-efficiency capillary electrophoresis system, equipped with ultraviolet detector; uncoated quartz capillary (Φ75μm×65cm, effective length 50cm).

[0022] Reagents required:

[0023] Melamine standard, sodium dodecyl sulfate (SDS), sodium dihydrogen phosphate (NaH 2 PO 4 ), phosphoric acid, acetonitrile, methanol, 0.1mol / L HCl, 0.1mol / LNaOH, ultrapure water, and the buffer solution and sample solution used were all filtered through a 0.45μm filter membrane before use.

[0024] 1) Determination of the best detection conditions

[0025] (1) Preparation of running solution and sample matrix

[0026] Prepare the concentration of 120mmol / L NaH with ultrapure water respectively 2 PO 4 And 150mmol / L sodium lauryl sulfate mother liquor;

[0027] a. Use a concentration of 120mmol / L NaH 2 PO 4 And 150mmol / L sodium lauryl sulfate ...