Melamine（Melamine）It is an important triazine nitrogen-containing heterocyclic organic chemical raw material, mainly used for melamine-Formaldehyde resin, widely used in industries such as wood processing, plastics, coatings, papermaking, textiles, and leather making, is a white crystalline substance.Melamine is not a food additive, why does it appear in milk and dairy products? In the food industry, it is often necessary to determine the protein content of food. Due to the over one million varieties of protein, direct measurement of protein technology is relatively complex. Therefore, the Association of Official Analytical Chemists (AOAC), an international organization, has developed the Kjeldahl method to determine the nitrogen atom content and indirectly calculate the protein content in food. Various foods have different conversion factors, among which the conversion factor for dairy products is 6.38. All countries in the world follow and implement this method standard, and China also uses this method standard as a national standard. Due to the higher proportion of nitrogen atoms in melamine (66%) compared to the average protein nitrogen content (about 16%), it has been used by some counterfeiters to create the illusion of high protein content in food, leading to serious food accidents such as the 2007 pet food contamination incident in the United States and the 2008 Chinese tainted milk powder incident，After entering the body, it seems that it cannot be metabolized and is excreted from the urine as it is. However, due to different physical conditions, some people may produce crystalline polymers that bind to cyanuric acid in the body, causing diseases such as kidney stones and bladder stones.The Sanlu milk powder incident has attracted widespread attention to melamine testing. The General Administration of Quality Supervision, Inspection and Quarantine and the National Standardization Management Committee have successively issued the "Method for Testing Melamine in Raw Milk and Dairy Products"（GB/T22388-2008）Rapid detection of melamine in raw milk-Liquid Chromatography Method（GB/T22400-2008）National standards. at the same timeThe General Administration of Quality Supervision, Inspection and Quarantine has officially announced the "Detailed Rules for the Examination of License Conditions for Enterprise Infant Formula Milk Powder"（2010Edition) and Detailed Rules for the Examination of Enterprise Dairy Product License Conditions（2010Version) requires all enterprises that have obtained licenses for dairy products and infant formula milk powder,exist2010Before the end of the year, it is necessary to reapply for permission, and the licensing authority must conduct a new review.2011year3the moon1From now on, dairy products and infant formula milk powder that have not been re licensed will be suspended. Compared with the original regulations, the new regulations have increased the product inspection items, especially for infant formula milk powder60The remaining enterprise self inspection projects. Both new regulations specifically require enterprises to ensure batch inspection of purchased raw milk and raw milk powder.

1instrumentOverview
1、Liquid chromatography for detecting melamine in milk and dairy productsLC-3000AThe entire system consists ofP3000binaryHigh pressure pumpUV3000Composed of detector, injection valve, solvent tray, chromatographic column, working software, etc; Installation, debugging, and usage are all very simple.
2、P3000High pressure infusion pump is usedCPLDA high-precision infusion pump system with technology as the core and controlled by a microcontroller. The all digital frequency generation system, advanced motor drive system, and user-friendly human-machine display interface make operation very convenient. The advanced pump head and single valve design ideas integrate the world's best experience, ensuring the accuracy and repeatability of infusion under various conditions.
3、UV3000It is a type of spectrophotometer that can be matched with any infusion pump and is widely used in fields such as chemical analysis, pesticides, pharmaceuticals, and chemical engineering. Adopting a fully digital and highly integrated design concept, greatly reducing the noise of the instrument; Based on digital signal transmission and processing, the signal of this detector can be directly input into the serial port of the computer for acquisition, completely eliminating the data acquisition card used by traditional instruments!
2、 Main features
1、P3000Series High Voltage Analysis/Semi prepared pump
Infusion method Double plunger reciprocating pump, double plunger suction.
display320X240Dot matrix large screen LCD display with blue backlight
system protection Slow start, stop**/*Small pressure adjustable, automatic storage
System connection1/8"pipeline connection
control standalone mode Set all working parameters through the buttons on the front panel. Working at a high level
When in pressure gradient mode, one of the pumps is the main pump, controlling other pumps of the same model
Pressure infusion pump, and can adjust the gradient mode achieved through the gradient curve on the screen
Verify.
Serial port mode pass throughRS232Control the high-pressure infusion pump through the mouth
power supply220V±10％，50Hz，400W
2、UV3000UV/VISdetector
control standalone mode By pressing the buttons on the front panel
Serial port mode pass throughRS232Oral software control
display320X240Large screen LCD display with adjustable blue backlight
Power supply power220V±10%，50Hz，60W
External dimensions and weight398X149X267mm(Deep)XtallXWide),14kg

threeInstrumentconfiguration

1. Method principle
useHPLCThe method for determining melamine is low-cost, does not require derivatization, and is simple and easy to implement. Use external standard method for quantitative analysis.
stem or root of plantsschemeuseLuchuang effective liquid chromatography instrumentLC-3000Binary high-pressure gradient, according to national standardsGB/T 22388-2008Testing for melamine in milk. This method is stable, reliable, and has a wide detection range.

2. Instrument and Reagent
Luchuang liquid chromatography instrumentLC-3000Binary high-pressure gradient system: infusion pump, equipped with gradient unit and online degassing device;LC-3000UV detector; manual injector7725i，colour spectrumworkstationN2000P,centrifuge1Tai (Turning Head)6*50ml）； Solid phase extraction column and extraction device; Nitrogen blower;
Melamine reference substance purchased fromsigmaThe company purchased liquid milk samples from supermarkets, and other reagents used in the experiment, such as trichloroacetic acid, sodium hydroxide, citric acid, and sodium octane sulfonate, were all analytical grade.

3. Chromatographic conditions
colour spectrumColumn:Venusil ASB-C18 4.6×250mm(You can also chooseC8Column)
Buffer solution:10mMcitric acid, 10mMsodium octane sulfonate
Mobile phase: buffer solution:acetonitrile=90：10
Injection volume:20uL
flow Speed:1.0mL/min
column Temperature:40linear measure

Lu ChuangThe clothingaffairadvantage:
1.Lu ChuangofserviceEngineers have undergone chemical analysis,Training on instrument repair and maintenance,They can maintain and repair various components,To ensure that your instrument runs smoothly and quickly,Can guarantee to solve your problems quickly.
2.Timely telephone technical support---The expert in troubleshooting will answer your call,Provide timely solutions to problems.
3.****Service----Lu ChuangProvide high-quality services within the scope of * * * *.
4.Flexible response time----After phone repair report，timelyTelephone guidance orDoor to door problem-solving
5.Uninterrupted24hourOnline Instrument Problem Answering
6.There are free and irregular chromatography training courses every year.The content includes chromatographic principles,Analysis, application,Technical instrument operation,helpAssist the causeObstacle removal and maintenance,Contact phone number: Please pay attention to product details，youalsoCan be done throughcompany websitequery.

dairy products│Milk testing and analysis│dairy productsAnalysis specificliquid phaseChromatograph │Milk and milk productscentreMelamineDetection/analysis

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