Analysis Of Organic Acid And Milk Proteins By Capillary Electrophoresis

Capillary electrophoresis (CE) is a new separation technique emerging in the 1980's. It has many charming characteristics, such as high separation efficiency, short analytical time, and small requirement for samples, which make CE meet the analytical demands for biomacromolecules in various fields of life sciences. It has become a versatile analytical technique. Organic acid come forth in the course of ferment is cell metabolizabiliti's result, It is very important that in the course of ferment organic acid is determined for optimizing fermentation's condition and confirming metabolic flux analysis. Lactic acid is an important acid in the organic acid, it is extensive applied for a number of domain. Such as: medicine, foodstuff, drink, et al. Focusing on the analysis of organic acids are usually determined by a number of chromatographic methods including gas chromatography (GC), high-performance liquid chromatography (HPLC). However, there is still a need for the drawback of chromatographic methods, such as the derivatisation steps often necessary in GC, or insufficient separation selectivity and efficiency sometimes encountered in HPLC. In this regard, capillary electrophoresis (CE) offers a number of promising features including short analysis times, high numbers of theoretical plates and separation selectivities. For this reasons, CE is becoming increasingly accepted for routine analytical work. The first part of this paper aims to set up a method of detection of Lactic acid and other organic acid of fermentation. Some experiments of this method are discussed in more detail below. 1.The concentration and PH of the buffer solution ,voltage and wave for analytical,temperature of capillary ,inject time of sample are investigated in details. 2. Lactic acid in the different condition (pH, temperature, ventilate quantity, carbon, nitrogen) is determined under the optimized condition. According to experiment's results, aiming at output of lactic acid the fermentation's condition is optimized. 3.The proposed method was applied to the determination of organic acid in fermentation liquid products at different time phase and the recoveries were in the range of 96.3～102.6%(n=3). Experiment result indicated: This method is simple, rapid, accurate and is suitable for optimizing condition of experiment in the course of ferment and monitoring products of ferment. Comparing to GC and HPLC, this method offers rapid and automated analyses with very high resolution. The second part of this paper aims to set up a method of detection of milk proteins. Protein is life activity's base substance, and it is important component of daily nutrition of human being. Protein possess of a number of function: enzymatic catalysis function, hormonal adjust function, human body immunity function et al. Milk and powder are composed of protein, fat, carbohydrate et al. therefore, detection of protein of milk and powder is very important to quality control of milk. However, Focusing on the analysis of protein are usually determined by Kaishi method. This method manipulation is very complexity, and waste time and staff, at the same time, this method can produce deleterious gas which jeopardize human being health. CE can overcome these drawbacks. Some experiments of this part are discussed in more detail below. 1. The profile of milk proteins is investigated by capillary electrophoresis (CE). The five proteins (α-La,β-Lg,α-CN,β-CN,κ-CN)of cow milk were...