酒类中微量甲醛的快速测定新方法

在FeCl3存在条件下,甲醛与自制蛋白液显色剂能生成紫色化合物,藉此可以定量测定微量甲醛。方法线性范围为1~10μg/10mL,线性相关系数r2=0.996,检出限为0.05μg/mL。用该法测定经活性炭脱色的啤酒和白酒中的甲醛含量,回收率为96.46%~103.32%,相对标准偏差为1.36%~2.09%(n=6)。     

Synthesis of monodisperse poly(chloromethylstyrene-co-divinylbenzene) beads and their application in separation of biopolymers

The monodisperse, porous poly(chloromethylstyrene-co-divinylbenzene) beads of 7.9 microm were prepared by a single-step swelling and polymerization method. The seed particles prepared by dispersion polymerization exhibited good absorption of the monomer phase. Based on this media, a weak cation-exchange (WCX) stationary phase for HPLC was synthesized by a new chemically modified method. The prepared resin has advantages of biopolymer separation, high column efficiency, low column backpressure, high protein mass recovery, and good resolution for proteins. The dynamic protein-loading capacity of the synthesized WCX packings was 18.2 mg/g. Five proteins were separated in 3.0 min using the synthesized WCX stationary phase. The experimental results show that the obtained WCX resin has very weak hydrophobicity. The WCX resin was also used for the rapid separation and purification of lysozyme from egg white in 5.0 min with only one step. The purity and specific bioactivity of the purified lysozyme were found to be more than 93% and 70 245 U/mg, respectively.     

二氧化碳溶剂浮选光度法测定高碘蛋总碘量

浮选法是二氧化碳气氛中,以溴化十六烷基三甲基铵(CTMAB)为捕收剂,用溶剂浮选吸光光度法对离子缔合物(CTMA~ I_3~-)的组成进行测定。试验表明,方法有较高的灵敏度,较好的准确性和重现性。     

Estimation of the size of liposomes by modified HDC

Internal calibration in modified hydrodynamic chromatography has been realized by the approach of Prieve and Hoysan, i.e. the use of polystyrene monodisperse latexes to evaluate the equivalent capillary radius, R. The value obtained has been used to estimate the average sizes of a variety of liposome samples from egg yolk lecithin.     

A new method for determination of antithrombotic activity of egg white protein hydrolysate by microplate reader

A new method for the determination of antithrombotic activity of egg white protein hydrolysate(EWPH)was developed using amicroplate reader.Reaction was carried out at 37℃ and pH 7.2 with fibrinogen concentration 0.1%.Microplate reading wasconducted at 405 nm.Inhibition rate of EWPH on thrombin activity showed linearity(R~2=0.9971),when the inhibition rate was inthe range of 10-90%.The lower limit of detection(LLD,at 99.7%probability)and the biological limit of detection(BLD,at 99.7%probability)of the method were 10.643 and 40 mg/mL,respectively.The repeatability standard deviation(R.S.D.)was 1.08%.Thestandard deviation of the method was 0.027 AT-U.     

苯、甲苯、一氯代苯对含水卵磷脂液晶结构影响的SAXS研究

苯及其衍生物甲苯,一氯代苯都是重要的有机试剂和化工原料,也是对人体有害的有机物。为了了解这些有机试剂对处于生物液晶态的生物膜毒害的机理,我们以含水卵磷脂组成的液晶体系作为人工模型用小角X射线散射(SAXS)方法探讨这些有机试剂对它们结构的影响。关于苯或其它非极性有机介质与含水卵磷脂形成液晶体系及其结构模型前人有一些报导。     

A new biomaterial,hen egg shell membrane,to eliminate heavy metal ion from their dilute waste solution

The egg shell membrane (ESM) is an intricate lattice network of stable and water-insoluble fibers with high surface area. ESM accumulates and eliminates various heavy metal ions from dilute aqueous solution with high affinity and in short contact time, depending on pH and characteristics of the individual ion. Under certain conditions, the level of precious ions, Au, Pt, and Pd accumulation approaches 55, 25, and 22% of dry wt of ESM, respectively. Also uranium uptake 30% of that of ESM. Experiments suggested that ESM is promising to use for the purpose of removal/recovery of metals and water pollution control.     

Use of the diphasic dialysis as a new extraction procedure in the determination of enrofloxacin and ciprofloxacin in egg

We have developed a new method for the analysis of the fluoroquinolones enrofloxacin and ciprofloxacin in eggs using a diphasic dialysis procedure as extraction and purification method. High pressure liquid chromatography-mass spectrometry (HPLC-MS) was used for the confirmatory determination of these compounds. The method was found to be linear between 10 and 800 ng g⁻¹ for enrofloxacin, and between 20 and 1600 ng g⁻¹ for ciprofloxacin. The recovery percentages were in the 70-104% range for enrofloxacin, and 55-97% for ciprofloxacin. The assay described was repeatable and reproducible with a limit of quantitation of 2 and 4 ng g⁻¹ for enrofloxacin and ciprofloxacin from egg, respectively.     

Quantitative determination of taurine in real samples by high-performance anion-exchange chromatography with integrated pulsed amperometric detection

As taurine is a very important compound involved in a large number of metabolic processes, it is naturally present in the mammal tissues and is often deliberately added in some foods as a fortifying component. A detailed knowledge of taurine metabolic roles in biological systems can be obtained only if a sensitive, reliable and rapid analytical method is available. This article describes the successful application of high-performance anion-exchange chromatography coupled with integrated pulsed amperometric detection (HPAEC-IPAD) for taurine determination in egg white and yolk samples, as well extracts of human serum and urine. Applications are shown for determination of taurine in soft drinks and pharmaceutical preparations where the taurine content was evaluated by standard additions. These results were achieved without prior derivatization of taurine.     

The influence of pH on phosphatidylcholine monolayer at the air/aqueous solution interface

The measurements of the interfacial tension at the air/aqueous subphase interface as the function of pH were performed. The interfacial tension of the air–aqueous subphase interface was divided into contributions of individuals. A simple model of the influence of pH on the phosphatidylcholine monolayer at the air/hydrophobic chains of phosphatidylcholine is presented. The contributions of additive phosphatidylcholine forms (both interfacial tension values and molecular area values) depend on pH. The interfacial tension values and the molecular areas values for LH⁺, LOH⁻ forms of phosphatidylcholine were calculated. The assumed model was verified experimentally.