Determination of 14 Organophosphorus Pesticide Residues in Mutton by Gel Permeation Chromatography-Gas Chromatography-Mass Spectrometry(GPC-GC-MS)

[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton.

Gel Filtration Chromatography Combined with Bradford Method for Determination of Total Residual Protein in Ferment Antibiotics

Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.

Molecular weight determination of a newly synthesized guanidinylated disulfide-containing poly(amido amine) by gel permeation chromatography

A cationic gene delivery vector, guanidinylated disulfide-containing poly(amido amine)(CARCBA), was synthesized by Michael addition reaction between N,N′-cystaminebisacrylamide(CBA) and guanidine hydrochloride(CAR). Gel permeation chromatography(GPC) was used to evaluate the molecular weight of synthesized CAR-CBA. Polyethyleneimine(PEI) with molecular weight of 25 kDa was adopted as a reference, and polyethylene glycols(PEG) with different molecular weights were used to establish a standard curve for determining the molecular weight of CAR-CBA. The effects of two critical factors, namely columns and eluents,on the molecular weight measurement of CAR-CBA were investigated to optimize the GPC quantitative method. The results showed that Ultrahydrogel columns(120, 250) and HAc–NaAc(0.5 M, pH 4.5) buffer solution were the optimal column and GPC eluent, respectively.The molecular weight of the synthesized CAR-CBA was analyzed by the optimized GPC method and determined to be 24.66 kDa.

Separation and purification of deoxynivalenol(DON) mycotoxin from wheat culture using a simple two-step silica gel column chromatography

Deoxynivalenol（DON） is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water（84：16, v/v）. A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography（preparative HPLC） to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol（17：1, v/v）, which provided a good elution effect selected on thin layer chromatography（TLC）. The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry（MS） and ~1H and ^（13）C nuclear magnetic resonance（NMR） spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.

Determination of Steroid Hormone Residues in Fish Tissues Using Gel Permeation Chromatography and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl ether.Differing from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile phase.The separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard method.This method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.

Gel Permeation Chromatography Purification and Gas Chromatography-Mass Spectrometry Detection of Multi-Pesticide Residues in Traditional Chinese Medicine

The measurement of 23 organochlorine, organophosphorus, and pyrethroid pesticides in typical traditional Chinese medicine (TCM), flos lonicerae, was made using gel permeation chromatography (GPC) purification and gas chroma- tography-mass spectrometry (GC-MS) detection. The pesticides were extracted with ultrasonic device and 5.0 mL mixture of ethyl acetate and cyclohexane (1:1, v/v). Coextractants from sample matrices which may have interfere to the qualitative and quantitative analysis, such as pigments, were removed using GPC purification. Simultaneous full scan and selective ion monitor (scan/SIM) mode for GC-MS was used for qualitative and quantitative analysis, which pro- vided retention time and characteristic fragments ratio for each pesticide so as to positively identify each analyte. Rela- tive standard deviations (RSDs) were within 7.7% (5.0 - 22.5 μg/kg, n = 3). The recoveries of pesticide standards at the spiked concentration of 5.0 - 22.5 μg/kg were between 87.1% and 110.9%. Limits of detection (LODs) for the analytes were 0.16 - 3.2 μg/kg, which could meet the demand of routine analysis and TCM quality control.

Separation and Purification of Acetophenones from Cynanchum bengei Decne Root Bark by Combination of Silica Gel and High-speed Counter-current Chromatography

[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.

GEL PERMEATION CHROMATOGRAPHIC ANALYSIS OF LACQUER POLYSACCHARIDE

Ten fractionated samples of Chinese lacquer polysaccharide in aqueous 0.1M NaC1 solution were studied by aqueous-phase gel permeation chromatography （GPC）. The universal calibration, broad MWD calibration and corrected column dispersion were adopted to the analysis of GPC chromatograms of the polysaccharide. The molecular weights M;, M;and polydispersity index M;/M;obtained from GPC are in good agreement with the results of light scattering and membrane osmometry. It is verified that the universal calibration concept is applicable to the lacquer polysaccharide having a number of side chains.

Perpentylated (2, 3, 6-Tri-O-pentyl)-β-cyclodextrin Used as Capillary Gas Chromatographic Stationary Phase Prepared by Sol-gel Technology

Capillary column preparation using perpentylated (2,3,6-tri-O-pentyl)-β-cyclodextrin asstationary phase by sol-gel technology with simplicity and rapidity is described. Multiplepreparation steps in conventional column technology were avoided. The prepared columns exhibitsatisfactory chromatographic performances and pronounced selectivity for a wide range of testsolutes, and have been successfully used for the separation of nitrotoluene, dimethoxybenzene,alcohols, alkanes, dimethylphenol and cresol isomers.

聚乙烯相对分子质量及其分布快速评价方法研究

以国内外采用不同工艺和催化剂生产的17种聚乙烯的测试结果为基础,通过理论推导与模型拟合相结合,建立了以熔体流动速率快速计算相对分子质量及其分布的方法,并由此计算出数均分子量。经验证,该方法准确性较好,可弥补凝胶渗透色谱法的不足,有利于装置生产过程中准确控制产品质量和提高新产品开发效率。

凝胶渗透色谱-光散射联用表征聚合物摩尔质量的实验教学改革

凝胶渗透色谱-光散射(gel permeation chromatography-light scatting,GPC-LS)联用是目前最常用的表征聚合物摩尔质量的方法之一,具有灵敏度高、结果准确等特点,在科学研究与生产实践中得到了广泛应用。“凝胶渗透色谱-光散射联用表征聚合物摩尔质量”是《高分子物理实验》课程中一个重要的教学内容。然而,目前的GPC-LS实验教学内容简单,缺乏深度。本文在该实验项目原有内容的基础上进行扩充,重新设计出多套实验项目:(1)选取商品化的聚苯乙烯为实验样品,利用GPC-LS对其摩尔质量、摩尔质量分布以及回转半径等分子结构参数进行表征;(2)选取两种分子结构参数接近的聚丙烯腈样品,借助质量微分分布曲线揭示这两种样品在摩尔质量分布中的细微差别;(3)选取一系列不同摩尔质量的聚乙二醇为实验样品,通过比较其色谱图分析摩尔质量的高低对色谱峰的影响;(4)选取3种不同的聚合物(聚丙烯腈、聚甲基丙烯酸甲酯、聚β-环糊精)样品,借助构象图对其分子链的构象进行分析。此外,本文对实验教学方法进行了改革,将被动学习转变为主动学习,提高了学生的自主学习能力。通过本实验项目的教学改革探索,使学生能更加全面地理解凝胶渗透色谱-光散射联用的原理及应用,开拓了学生的知识视野,激发了学生的学习热情,提升了实验教学效果。

Bio-Gel P-2分离低聚木糖的特性

以聚丙烯酰胺凝胶（Bio-Gel P-2）为层析介质，快速蛋白液相层析（FPLC）系统为平台，以脱气超纯水为洗脱液，对其分离低聚木糖的特性进行了探讨。研究表明，Bio-Ge lP-2可用于低聚木耱分离，采用Bio-Gel P-2分离低聚木糖时，木二糖至木六糖各相邻组分之间的选择因子α和分离度R分别介于1．13～1．18和0．83～1．11之间，而且各组分与层析介质Bio-Gel P-2之间无特异性吸附现象，能完全按照分子质量大小进行分离。通过1次分离可获得纯度分别为86．94％、82．90％、88．30％、64．20％和77．89％的木二糖至木六糖溶液。

基于FⅧ探讨不同脱盐方式的效果及对其成分的影响

目的基于人凝血因子Ⅷ(human coagulation factorⅧ,FⅧ)比较5种脱盐方法的脱盐效果及对FⅧ成分的影响,为蛋白脱盐方式提供参考。方法分别用Sephadex G-25 Medium凝胶、Fractogel EMD BioSEC凝胶、超滤、室温透析和4℃透析5种方法对人FⅧ进行脱盐处理。通过Na^(+)、柠檬酸根离子、甘氨酸去除率评估脱盐效果。通过脱盐前后FⅧ蛋白回收率、FⅧ活性(coagulation factorⅧactivity,FⅧ∶C)、VWF抗原(VWF antigen,VWF∶Ag)、VWF活性(VWF activity,VWF∶Ac)、VWF多聚体及SDS-PAGE分析,评估其对FⅧ成分的影响。结果在脱盐效果方面:Na+在超滤脱盐时去除率最低,为(97.90±0.06)%,Fractogel EMD BioSEC凝胶脱盐去除率最高,为(99.82±0.07)%。除Sephadex G-25 Medium凝胶脱盐与Fractoge EMD BioSEC凝胶脱盐间Na^(+)去除率无统计学意义(P=0.90)外,其他4种方法间Na+去除率存在统计学意义。甘氨酸在超滤脱盐时去除率最低,为(95.78±0.42)%,Fractogel EMD BioSEC凝胶脱盐去除率最高,为(99.81±0.08)%。除超滤脱盐外,其他4种脱盐方法间甘氨酸去除率无统计学意义。柠檬酸根离子在5种方法间去除率均无统计学意义(P=0.85)。对于FⅧ成分的影响方面:超滤脱盐FⅧ∶C、VWF∶Ag、VWF∶Ac及蛋白回收率最高,分别为(18.34±1.99)IU/mL、(11.81±0.33)IU/mL、(12.26±0.58)IU/mL、(97.13±1.37)%。5种方法脱盐前后VWF∶Ac/VWF∶Ag无明显变化。SDS-PAGE及VWF多聚体分析表明,不同脱盐方法对蛋白组成种类影响不明显。结论尽管不同方式脱盐对FⅧ蛋白组成种类无明显影响,但脱盐效果存在差异,不同方式脱盐对蛋白回收率、FⅧ∶C、VWF∶Ag及VWF∶Ac影响显著。蛋白处理过程中,对于脱盐方式的选择应给予足够重视。

凝胶渗透色谱测试天然橡胶相对分子质量及分布的优化方法建立

为摸索凝胶渗透色谱仪器测试条件对天然橡胶相对分子质量及分布测试结果的影响,利用凝胶渗透色谱对同一天然橡胶样品进行分子量及分布测试,确定了最佳的凝胶渗透色谱测试条件:检测器为示差折光检测器,流动相为四氢呋喃,流速为1.0mL/min,柱温和检测器温度为40℃,进样体积为30μL。将其运用在不同品种天然橡胶样品的测试分析中,结果表明该方法准确度高(>98%),重现性好(RSD<5%),为今后利用凝胶渗透色谱仪测试天然橡胶相对分子质量及分布测试提供了试验指导和理论基础。

生物样品中新污染物筛查:透析和凝胶渗透色谱联用净化方法

以河蚬为代表,建立了一种能有效去除生物样品中脂肪及其它内源性干扰物,并保留性质广泛的新污染物的净化方法。选择理化性质迥异的35种污染物(log Kow为-1.30~8.41),优化生物样品萃取、透析及凝胶渗透色谱(GPC)分离方法,并验证了方法可行性。优化的样品前处理方法为:样品先后采用正己烷、丙酮、二氯甲烷混合溶液(体积比2∶2∶1)和乙腈加速溶剂萃取,提取液经4次透析后再用GPC净化,目标物使用气相色谱-质谱和液相色谱-串联质谱进行分析。采用香兰素-磷酸法测定每一净化步骤后样品的脂肪含量,并结合色谱-质谱全扫描分析,检验干扰物的去除效率。结果表明,净化后河蚬提取物中残余的脂肪含量小于1.06%,GPC中待测分析物的流出时间为8~20 min,平均回收率为55.1%±13.0%,相对标准偏差为1.4%~9.2%。净化后的河蚬生物样品中脂肪和部分内源性物质被有效去除,宽泛程的目标物的回收率均达到环境样品痕量新污染物检测的要求,所建方法可用于生物样品非目标筛查的前处理。

羟基邻位三齿[OSO]双酚钛络合催化剂催化乙烯聚合性能的研究

以4-叔丁基苯酚为原料,通过改变羟基邻位取代基经过溴甲基化、亲核取代以及金属络合反应得到了4种三齿[OSO]双酚钛络合催化剂[S(2-CH_(2)-4-^(t)Bu-6-R-C_(6)H_(2)O)2]TiCl_(2)(R^(1)=CMe_(3),R^(2)=CPhMe_(2),R^(3)=CPh_(2)Me,R^(4)=CPh_(3))。在温度30,50,70℃,压力0.6 MPa的条件下探讨乙烯聚合反应性能,通过改变催化剂的Al/Ti比和反应时间,得到不同条件下的聚烯烃产物,并利用凝胶色谱(GPC)对产物进行表征分析。对不同反应条件下的这4种催化剂进行比较,由于R基团位阻效应的影响,位阻越大催化剂的活性越高,结合实验结果得出,在50℃条件下[S(2-CH_(2)-4-^(t)Bu-6-CMePh_(2)-C_(6)H_(2)O)_(2)]TiCl_(2)催化剂的活性最高,为6.7×10^(6)g PE/(mol Ti·h)以及得到的聚烯烃产品M W为1.68×10^(5),分子量分布为3.2。

干腌火腿活性肽的抗氧化性能研究与鉴定

以金华火腿为研究对象,借助凝胶层析色谱对火腿粗肽进行初步分离,测定各组分的抗氧化性,将样品经由配备在线钠喷离子源的液相色谱串联质谱分析,采用串联EASY-nanoLC 1200的Orbitrap Q-Exactive Plus质谱仪鉴定金华火腿中所含活性肽的序列,发现了31条丰度高且未被鉴定的短肽。并利用PeptideRanker进行预测分析,得到丰度和活性都比较高的3个肽段,氨基酸序列分别为:DHDGPDHW、FPPDVGD、PFGDTH。用DPPH自由基清除能力、ABTS阳离子自由基清除能力和羟自由基清除能力检测抗氧化能力,证明金华火腿粗肽液具有良好的抗氧化性。红外光谱发现粗肽在1600~1700 cm-1有吸收带。通过合成短肽,验证肽段的抗氧化能力,分子对接实验表明超氧化物歧化酶与DHDGPDHW、FPPDVGD、PFGDTH均有结合能力,FPPDVGD的结合能力最强为-6.6 kcal/mol。综上,FPPDVGD具有较好的抗氧化能力,可作为天然抗氧化剂应用于食品、药品或化妆品,应用前景非常广泛,为干腌制品的进一步开发利用提供理论支持。

益肾固精暖脐贴制备工艺的研究

目的研究益肾固精暖脐贴的提取工艺及其成型工艺。方法以蛇床子素、羟基-α-山椒素、金丝桃苷以及浸膏得率为考察指标,以提取时间、提取溶媒倍数、乙醇浓度为考察因素,运用Box-Behnken设计-响应面法优选出最佳提取工艺;以凝胶贴膏的初黏力、持黏力、剥离强度、感官评价为指标,采用D-最优混料设计优选益肾固精暖脐贴的最佳成型工艺。结果益肾固精暖脐贴的最佳提取工艺为回流提取120 min,提取溶媒倍数为12,乙醇浓度为57%,同法提取2次;最佳成型工艺的质量比为NP700占6.00%、PVP-k90占0.60%、甘羟铝占0.15%、填充剂5.76%、EDTA-2Na占0.10%、甘油占21.76%、柠檬酸占0.20%、水和药液总量占65.43%。结论该实验优选的益肾固精暖脐贴的提取工艺及其凝胶贴膏的制备工艺稳定可行,可为该产品的进一步开发利用提供参考。

茉莉花和勿忘我花瓣在沐浴露中的应用

为了找到合适的悬浮剂和防腐剂,在适当的条件下对花瓣进行处理,从而让花瓣在加入到沐浴露产品后,能够长期保持良好的形态,使用高效液相色谱仪(HPLC)和场发射扫描电子显微镜(FESEM)对茉莉花和勿忘我花瓣在预处理前后,以及置于沐浴露5年后的情况进行研究。结果表明,干花瓣采用沸水和强氧化剂处理后,脱去了色素和易挥发的成分;置于沐浴露中5年,依然能够保持花瓣形状完好且均匀悬浮,同时未发现微生物超标现象;由于花瓣中非挥发性物质减少,导致花瓣颜色变淡,质地变薄,但有利于花瓣形态在沐浴露配方中保持稳定。

基于多指标成分定量的痛舒凝胶贴膏质量评价研究

目的基于多指标成分TLC鉴别及HPLC定量分析评价痛舒凝胶贴膏质量。方法采用TLC法对剂型改良后的痛舒凝胶贴膏中延胡索乙素、芍药苷、粉防己碱、乌药醚内酯以及苍术、枳壳进行定性鉴别;HPLC法测定该剂型中主要有效成分延胡索乙素、芍药苷、粉防己碱、乌药醚内酯的含量。结果组方中6味药材TLC结果斑点清晰,显色良好且阴性无干扰。延胡索乙素、芍药苷、粉防己碱、乌药醚内酯分别在4.30~272.50μg/mL(r=0.9999)、21.10~1350.00μg/mL(r=0.9998)、4.10~262.40μg/mL(r=0.9998)、3.60~232.50μg/mL(r=0.9986)的浓度范围内线性关系良好,平均加样回收率范围区间为98.96%~99.52%,RSD均≤1.54%(n=9)。结论所建立的多指标TLC定性鉴别及HPLC定量方法专属性高,操作简便易行,可用于该组方剂型改进后的质量评价。