Method for testing melamine in raw milk and dairy products and preprocessing device

A technology for melamine and sample pretreatment, which is applied to measurement devices, material separation, and analysis of materials, etc., can solve problems such as inability to adapt to melamine detection pressure and low reliability, and achieve the effects of saving manpower and material resources, easy operation, and improving extraction efficiency.

Inactive Publication Date: 2010-07-14
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These cumbersome or low-reliability detection methods can no longer adapt to the current detection pressure of melamine in the food field.
How to make use of the advantages of high precision and high sensitivity of liquid chromatography and gas chromatography while overcoming the time-consuming and labor-intensive shortcomings of pretreatment has become an important issue in this detection field.

Method used

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  • Method for testing melamine in raw milk and dairy products and preprocessing device
  • Method for testing melamine in raw milk and dairy products and preprocessing device
  • Method for testing melamine in raw milk and dairy products and preprocessing device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0053] Preparation of sample pretreatment device:

[0054] Cut the hollow fiber membrane into 2.8 cm long sections, the material of the hollow fiber membrane is polyvinylidene fluoride fiber membrane, the wall thickness is 200 μm, the inner diameter is 1.2 mm, and the pore diameter is 0.2 μm; take a pipette tip of 5-10 μL as a plastic suction Cut off the thick end of the suction head, keep the pointed end, and cut it into 2.7 cm long sections. Soak the cut membrane and the suction head 4 in acetone for 20 minutes for ultrasonication, take it out and dry it; then glue the hollow fiber membrane and the tip of the suction head 4 tightly with glue, and close the other end of the hollow fiber membrane with flat tweezers until A transparent mark appears on the membrane, and the extraction tube is made;

[0055] Immerse the extraction tube in n-octanol (organic phase), and take it out after ultrasonication for 10 seconds, so that n-octanol is filled in the pore wall of the hollow fi...

Embodiment 2

[0060] Blank test and standard recovery test of the detection method:

[0061] Prepare 1mg / mL melamine standard solution. Accurately measure 8 mL of liquid milk samples, add 8 μL of melamine standard solution (that is, the addition level is 1 μg / mL) to the spiked group, and not to the blank group, and process three samples in parallel in each group. Immerse the extraction tube in n-octanol and sonicate for 10 seconds, take it out and absorb the excess n-octanol with lens tissue. Insert the extraction tube into the sample bottle, draw 20 μL of distilled water (receiving phase) into the film with a micro-injector, and seal the tube opening with a parafilm. Put the extraction device into a shaker, shake and extract at a speed of 600r / min for 90min at room temperature. After extraction, absorb all the receiving phase, transfer to the sample injection vial, and wait for HPLC detection. Weigh 1.01g of sodium heptanesulfonate and 1.05g of citric acid, dissolve in water and set the...

Embodiment 3

[0069] Test milk powder samples:

[0070] Prepare 1mg / mL melamine standard solution. A small packet (25g) of commercially available milk powder was dissolved in 200mL of warm water, and ultrasonicated for 5 minutes to prepare a milk sample. Accurately measure 8 mL of milk samples, add 16 μL of melamine standard solution (that is, the addition level is 2 μg / mL) to the spiked group, and not to the blank group, and process six samples in parallel in each group. Immerse the extraction tube in n-octanol and sonicate for 10 seconds, take it out and absorb the excess n-octanol with lens tissue. Insert the extraction tube into the sample bottle, draw 20 μL of distilled water (receiving phase) into the film with a micro-injector, and seal the tube opening with a parafilm. Put the extraction device into a shaker, shake and extract at a speed of 600r / min for 90min at room temperature. After extraction, absorb all the receiving phase, transfer to the sample injection vial, and wait for...

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Abstract

The invention discloses a method for testing melamine in raw milk and dairy products. The high-efficient liquid phase chromatography is adopted for testing, the samples of raw milk and dairy product are preprocessed by way of hollow fiber membrane liquid-liquid-liquid phase microextraction, the organic phase is adsorbed on the pore wall of the fiber membrane, the aqueous phase as the receiving phase exists in the fiber membrane, and after being soaked in the sample solution to be detected and is extracted, the fiber membrane is directly tested by HPLC. Meanwhile, the invention also discloses a sample preprocessing device for the method and a preparation method thereof. The method is sensitive and reliable, the operation of the testing method is simple and convenient, the cost is saved, and the method is environment-friendly.

Description

technical field [0001] The invention belongs to the field of food testing, and relates to a method for analyzing organic matter by liquid-phase microextraction, more specifically, a hollow fiber membrane three-phase liquid-phase microextraction-high performance liquid chromatography method is used to analyze raw milk and dairy products. Determination of melamine. Background technique [0002] Melamine was originally an important chemical raw material and a commonly used industrial chemical. A far cry from the food realm. So in September 2008, the Sanlu infant milk powder contamination incident in China made melamine a milk accessory for a while. The detection of melamine in milk or dairy products has suddenly become an important issue in the field of analytical chemistry at home and abroad, and is closely related to food safety testing. [0003] Since melamine is a chemical raw material, it is not allowed to be added to food, so before that, all countries have no national...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N30/06G01N30/08
Inventor 欧阳钢锋阮静雯鲁统部王录才朱芳何建国
Owner SUN YAT SEN UNIV
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