溴化衍生-气相色谱法测定水中丙烯酰胺的含量

气相色谱法(GC)是一种低成本检测半挥发化合物有效的途径,并是许多水源检验室广泛使用的分析工具,本文通过实验,采用溴化衍生-气相色谱法对水中的丙烯酰胺进行了分析。     

裂解色谱对淀粉丙烯酰胺接枝物的研究

本文用裂解色谱法对淀粉丙烯酰胺接枝共聚物进行裂解分析,从裂解谱图上能够得到淀粉和丙烯酰胺的特征裂解碎片峰,同时从接枝物中淀粉和丙烯酰胺特征碎片峰的面积可计算出淀粉或丙烯酰胺的相对比例。确定淀粉在接枝物中的分布,由接枝物的裂解色谱图还可得到峰面积和接枝率的关系图,从此关系图中可直观得到接枝物的接枝率,对于研究淀粉接枝共聚物的结构和性能有一定的参考意义。     

广西:《食糖产品色值检测专用滤膜质量要求》等6项地方标准顺利通过审定

近日,广西质检院、国家食糖及加工食品质检中心主持起草的《食糖产品色值检测专用滤膜质量要求》《食糖检验留样贮存设施基本要求》《白砂糖产品黄粒数的检测方法》《制糖生产过程中间制品蔗糖含量检测高效液相色谱法》《制糖生产过程中间制品中亚硫酸根离子、磷酸根离子含量的检测离子色谱法》《食糖产品中丙烯酰胺残留量的测定气相色谱-质谱法》等6项广西地方标准顺利通过广西质监局专家组的审定。据了解,该6项广西地方标准是南宁市科技攻     

纸材料用淀粉接枝聚丙烯酰胺的制备与表征

以过硫酸铵为引发剂,制备了纸包装材料用淀粉接枝聚丙烯酰胺聚合物,并采用红外光谱仪、热重分析仪和扫描电子显微镜研究了聚丙烯酰胺、淀粉以及淀粉接枝聚丙烯酰胺聚合物的结构。通过红外光谱分析,确认淀粉已接枝上聚丙烯酰胺;通过热重分析,发现淀粉接枝聚丙烯酰胺比聚丙烯酰胺更稳定;通过扫描电镜分析,可知淀粉接枝聚丙烯酰胺是接枝在淀粉颗粒表面的,呈网状结构。     

三次采油用梳形丙烯酰胺类共聚物的研究进展

从介绍梳形丙烯酰胺类共聚物的合成方法出发,综述了近年来三次采油用梳形抗盐丙烯酰胺共聚物和梳形活性丙烯酰胺共聚物的研究进展,并阐明了目前三次采油用梳形丙烯酰胺类共聚物存在的不足,提出了梳形丙烯酰胺类共聚物的发展方向.     

功能性聚丙烯酰胺类微球的制备及应用

介绍了功能性聚丙烯酰胺类微球的各种制备方法,主要为分散聚合法和无皂乳液聚合法。其中重点介绍了改进的无皂乳液聚合法-超声波无皂乳液聚合法、紫外光引发无皂乳液聚合法和微波加热无皂乳液聚合法;同时,还介绍了功能性聚丙烯酰胺类微球的种类和应用,诸如:温敏性聚丙烯酰胺微球、磁性聚丙烯酰胺微球、pH值响应聚丙烯酰胺类微球以及聚丙烯酰胺与无机微粒形成的复合微球。并对功能性聚丙烯酰胺类微球研究作了展望。     

改性聚丙烯酰胺吸水性树脂的吸水性能及抗碎化性能

以丙烯酰胺(AM)为单体,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,2-丙烯酰胺基-2甲基丙烷磺酸钠(AMPS-Na)、3-烯丙氧基-2-羟基-1-丙烷磺酸钠盐(HAPS)两种可聚合表面活性剂作为改性剂,与丙烯酰胺共聚,合成了两种改性聚丙烯酰胺吸水性树脂。研究了不同掺量交联剂与改性剂对聚丙烯酰胺吸水性树脂的吸水性能及抗碎化性能的影响。结果表明:提高交联密度可降低聚丙烯酰胺吸水性树脂的吸水倍率,但对其抗碎化能力无改善效果;AMPS改性后的聚丙烯酰胺吸水倍率增大,但其脆性增加,抗碎化能力变差;HAPS改性后的聚丙烯酰胺吸水性能降低不显著,而且韧性和抗碎化能力大大改善。     

淀粉接枝聚丙烯酰胺在纸包装材料中的应用

介绍了淀粉接枝聚丙烯酰胺在纸包装材料中的应用,探讨了淀粉接枝聚丙烯酰胺对纸张的助留、助滤作用及增强作用,并将其与聚丙烯酰胺的应用作了对比.结果表明:淀粉接枝聚丙烯酰胺对纸料有一定的留着效果,并且效果优于聚丙烯酰胺;随着淀粉接枝聚丙烯酰胺用量的增加,纸张的定量随之增加,撕裂度和耐折度逐渐下降,但抗拉强度和裂断长先增加后减少.     

P(NIPA-co-AM)超大孔水凝胶的制备及其性能

以N-异丙基丙烯酰胺(NIPA)、丙烯酰胺(AM)为单体,过硫酸铵为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,采用泡沫分散聚合法制备N-异丙基丙烯酰胺与丙烯酰胺共聚物[P(NIPA-co-AM)]超大孔水凝胶,研究了丙烯酰胺、引发剂、交联剂、盐酸、碳酸氢钠用量对水凝胶溶胀、退溶胀性能的影响,通过DSC、SEM、FTI...     

丙烯酰胺单体精制技术研究

本文采用聚合实验对比了丙烯酰胺中杂质对聚合产品质量的影响，认为对丙烯酰胺单体进行精制，除去有害杂质，是合成高分子量聚丙烯酰胺所必须的。运用活性炭和离子交换树脂等精制手段进行丙烯酰胺精制技术研究，精制后的丙烯酰胺在聚合上表现出良好的活性，聚合产品质量显著提高，满足生产高分子量聚丙烯酰胺的要求。     

色谱分析法在斑蝥黄测定中的研究进展

本文从斑蝥黄的稳定性、样品的前处理技术和检测方法等方面,着重阐述了色谱技术在斑蝥黄测定中的应用,包括高效液相色谱法、高效液相色谱-串联质谱法。     

Analysis of chromatography by plate theory

Recent advances in the plate theory for the analysis of chromatography are reviewed in this article. It can be seen that through a proper definition of height equivalent to a theoretical plate, both plate model and mass-balance model can be closely related. The plate height expressions resulting from various approaches are almost the same in linear chromatography. The emphasis of this article is placed on the extension of plate theory to the configurations of chromatography other than the conventional axial-flow column and to the nonlinear chromatography. The concept of volume equivalent to a theoretical stage has been developed to overcome the problem of design and scale-up of chromatography other than axial-flow configuration. In nonlinear chromatography used for the purification of biomolecules, the retention behavior and the band broadening could be significantly affected by concentration and volume overloads and slow adsorption kinetics. Works on the derivation of thermodynamic and kinetic contributions to plate height owing to nonlinear isotherm and volume overload are reviewed and compared. To conclude this review, future prospects of the application of the plate theory is also presented.     

一种高效制备河豚毒素(TTX)方法的研究

为了获得大量高纯度的河豚毒素TTX,利用D201大孔树脂层析、超滤、离子交换层析、分子筛层析、反相制备液相色谱等方法,从假睛东方鲀(Fugu pseudommus)肝脏中分离纯化得到TTX晶体,得率为81．1％。获得的TTX晶体利用电喷雾电离质谱(ESI—MS)及核磁共振谱(NMR)进行结构验证,用高效液相色谱(HPIE)进行纯度分析定量,其纯度为99．5％。     

胡椒粉中胡椒碱两种测定方法的比较

本文采用了无水乙醇回流法及无水乙醇超声提取法两种处理方法后分别利用液相色谱仪、紫外分光光度法两种检测方法检测胡椒粉中的胡椒碱含量,通过比较确定了超声提取加液相色谱法是一种适宜实验室推广的方便、高效、准确的检测方法。     

Application of countercurrent chromatography/thermospray mass spectrometry for the identification of bioactive lignans from plant natural products

The versatility and resolving power of countercurrent chromatography (CCC) has been demonstrated with a newly developed analytical high-speed planet centrifuge system. Interfacing countercurrent chromatography with mass spectrometry (MS) provides a new analytical methodology that integrates the advantages of countercurrent chromatography with the low detection limit and identification capability of mass spectrometry. In this paper the capability of thermospray CCC/MS is demonstrated in identifying and validating the bioactive and structurally known lignans from a crude extract of Schisandra rubriflora Rhed et Wils, a traditional Chinese herbal medicine for treatment of hepatitis.     

Chiral separations of polar compounds by hydrophilic interaction chromatography with evaporative light scattering detection

The chiral separations of drug substances and underivatized amino acids were demonstrated in this study through the use of hydrophilic interaction chromatography (HILIC). The polar character of the model compounds presented challenges for their analysis by traditional modes of chromatography, but through the employment of multimodal chromatography utilizing the HILIC mechanism and cyclodextrin- or teicoplanin-derivatized stationary phases, effective resolution was achieved. The analytes lacked sufficient ultraviolet chromophores, requiring their determination by evaporative light scattering detection. HILIC was demonstrated to represent a novel technique for the facilitation of chiral chromatography by providing an environment of solubility and retention that could not be achieved through the use of the traditional methods of reversed-phase, normal-phase, or polar organic mode.     

用TLC／FID棒薄层色谱测定重质油的族组成方法的研究

建立了快速重质油族组成的薄层色谱／氢火焰（TCL/FID）法,用两种展开剂可将试样很好地分离成饱和烃、芳烃、胶质及沥青质三个组分。本方法与经典柱色谱分析方法分析结果非常吻合,具有很好的重复性和准确性。     

Improvements in polymer characterization by size-exclusion chromatography and liquid chromatography at the critical condition by using enhanced-fluidity liquid mobile phases with packed capillary columns

Microscale chromatography has found numerous applications in liquid chromatography. The combination of enhanced-fluidity liquid mobile phases with packed-capillary LC is evaluated for polymer characterization using size-exclusion chromatography (SEC) and liquid chromatography at the critical condition (LCCC) phase. Separations of polystyrene polymers and copolymers are completed using liquid chromatography at the critical condition. The critical conditions of polystyrene polymers were approached by changing the concentration of CO(2) in the mixture combined with temperature and pressure variation. Because the solvent strength of enhanced-fluidity liquid mixtures is affected by temperature and pressure variation, the solvent strength could be fine-tuned to accurately find the critical condition. Long packed capillaries could be used in this application because the enhanced-fluidity mobile phases have low viscosities. High efficiencies resulted. The performance of packed-capillary and analytical-scale analytical columns containing the same packing material was compared for a challenging separation at the critical condition.     

小麦粉及其制品中溴酸钾含量的测定

本方法采用离子色谱与电感耦合等离子体质谱联用技术(IC-ICP-MS)检测小麦粉及其制品中溴酸钾的含量。该方法利用离子色谱将溴酸根与溴离子等含溴化合物分离后在ICP-MS上通过质谱的高选择性检测而排除氯离子和有机酸等物质的干扰。该方法对溴酸钾的检测限可达0.02mg/kg。     

一氧化碳定值方法的研究

目前国内很多实验室采用气相色谱法对CO组分进行定值,本文就气相色谱法和气体滤光相关技术对CO的定值结果进行了比对.实验结果表明:采用气体滤光相关技术所得实验数据比气相色谱法定值准确,方法精密度高,且方便快捷,可成为今后对CO气体进行实验室分析之首选.