说明：
According to the first method of high performance liquid chromatography in GB/T 22388-2008 Method for the Detection of Melamine in Raw Milk and Dairy Products, a certain amount of homogeneous raw milk or dairy products (hereinafter referred to as samples) was weighed and added with acetonitrile to precipitate and separate protein, and trichloroacetic acid solution was added to convert melamine into melamine acidifier under acidic conditions, ultrasonic, centrifugation and filtration separation. After protein precipitation, the sample solution was injected into high performance liquid chromatography after purification by mixed cation exchange solid phase extraction column and concentration by nitrogen blowing. The melamine content in the sample was determined by reversed phase chromatograph...
Time:
2018
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06
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05
Clicks:
142
说明：
The contents of 17 amino acids, glycine, leucine, methionine, tyrosine, histidine, threonine, alanine, isoleucine, tryptophan, cystine, lysine, aspartic acid, arginine, phenylalanine, proline, glutamic acid and arginine, were determined before and after derivation. The results of separation by RIGOL L-3000 high performance liquid chromatography system show that the method has high reproducibility, good linearity, and can fully meet the requirements of the Pharmacopoeia of the People's Republic of China. The method is accurate and sensitive.ClassificationOther/BiologicalReference standardKey wordEnglish：Amino acid ，C18 column，HPLCAmino acid is the most basic substance that constitutes the protein of organism and related to life activities. It is the basic unit of protein molecule in org...
Time:
2018
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06
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05
Clicks:
124
说明：
Amino acid analysis is an important auxiliary method for the determination of nitrogen content and protein content in feed. With the development of reversed-phase chromatography technology, the determination of amino acid by reversed-phase high performance liquid chromatography is becoming more and more common. In this experiment, Venusil-AA amino acid analysis method was packaged on RIGOL L-3000 high performance liquid chromatograph to establish an HPLC method for amino acid analysis. The specific operation was to use n-leucine as internal standard, phenyl isothiocyanate (PITC) as pre-column derivative reagent, and C18 column was used for binary gradient elution at 40 (?) and detection at 254 nm wavelength.Key words: pre-column derivatization of phenyl isothiocyanate amino acids by high p...
Time:
2018
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06
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05
Clicks:
288
说明：
According to the content determination method of preservatives in 'Hygienic Code for Cosmetics (2007 Edition)', a certain amount of uniform cosmetics (hereinafter referred to as samples) were weighed, methanol was added and treated by ultrasound. The sample solution was injected into the high performance liquid chromatography (HPLC). The samples were separated by reversed phase chromatography, detected by ultraviolet detector, and the content of preservatives in the samples was quantitatively determined by standard working curve method.The operation steps include: 2.1, reagent solvent preparation; 2.2, standard working curve preparation; 2.3, sample pretreatment; 2.4, chromatographic analysis; 2.5, data processing.Requirements for laboratories:Laboratory environmental requirements:...
Time:
2018
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06
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05
Clicks:
132
说明：
Artificial synthetic colorants, also known as synthetic pigments, are usually made from benzene, toluene and other raw materials by first preparing pigment intermediates, then sulfonating, coupling, condensation and azo reaction of one or two intermediates. 'Determination of synthetic colorants in food' (GB/T 5009.35-2003), polyamide was used to adsorb synthetic colorants in food and eluted with ethanolamine solution. The adsorption capacity of polyamide to synthetic pigments will be affected by temperature. Samples and eluents need to be heated in the experiment, and ethanolamine concentration takes too long. This method is not suitable for simultaneous treatment of large quantities of samples and is not easy to be transplanted by automated methods. Most synthetic colorants have t...
Time:
2018
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06
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05
Clicks:
119
说明：
On October 22, 2012, the Ministry of Agriculture announced in its announcement No. 1849 'Licensing Conditions for Feed Manufacturing Enterprises' and 'Licensing Conditions for Mixed Feed Additives Manufacturing Enterprises'. The two licensing conditions will come into effect on December 1, 2012. These two conditions not only specify the minimum area of the plant area, production technology and equipment, production capacity, but also stipulate that there must be a feed testing laboratory. It is stipulated that the testing laboratory must be equipped with instruments, including atomic absorption spectrophotometer, high performance liquid chromatography and other related testing instruments.For feed enterprises, when applying for batch numbers of feed products, enterprises ar...
Time:
2018
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06
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05
Clicks:
21