火焰原子吸收光谱法和电感耦合等离子体发射光谱法测定黄酒中氧化钙含量的方法对比研究

目的比较火焰原子吸收光谱法(flame atomic absorption spectrometry,FAAS)和电感耦合等离子体发射光谱法(inductively coupled plasma optical emission spectrometry,ICP-OES)测定黄酒中的氧化钙含量。方法将黄酒样品、加标试样样品、质控样品通过微波消解仪消解,定容后分别用火焰原子吸收分光光度计,电感耦合等离子体发射光谱仪测定样品中钙的含量,并对2种方法的线性范围、方法检出限、精密度和回收率进行考察。结果FAAS法的方法检出限和精密度分别为0.10μg/m L和0.0223 g/L,ICP-OES法的方法检出限和精密度分别为0.015μg/m和0.00873 g/L,ICP-OES法有更低的检出限和更高的精密度,2者检测样品结果相对标准偏差(RSD)在3%以内,回收率在96.4%～102.6%之间,相关系数r为0.9995～0.9999,这2种方法中标准参考物质菠菜(GSB-6)中的钙含量的测定值在标准参考范围内。结论FAAS法测定黄酒中的氧化钙,前处理操作复杂,并且酸度对测定结果有较大影响,同时该法的检出限较高和精密度较低,而ICP-OES法线性关系好,检出限低,稳定性好,回收率高,测定结果准确,因此该法更适合黄酒中氧化钙的测定。     

紫苏球蛋白乳化性及其O/W乳液的稳定性研究

将紫苏籽粉碎过60目筛后采用石油醚脱脂得到紫苏籽脱脂粉,采用osborne法提取紫苏球蛋白,研究其乳化性质,并将其应用于水包油(oil in water,O/W)乳液,进一步研究紫苏球蛋白浓度对乳液稳定性影响.结果表明,紫苏脱脂粉中球蛋白含量较高,其溶解性、乳化活性和乳化稳定性在pH 2～9,呈现U型曲线;球蛋白质量浓...     

Review of the structural characterization,quality evaluation,and industrial application of Lycium barbarum polysaccharides

BackgroundLycium barbarum polysaccharides (LBPs) are considered to be the major bioactive components in L. barbarum. Due to the considerable health benefits of LBPs, and the significant research interest in LBPs, quality evaluation of LBPs and their related products is imperative for ensuring their efficacy and safety. The bioactivities of polysaccharides are closely associated with their physicochemical properties, which can be easily monitored via chemical techniques. Therefore, analysis of physicochemical properties is a more straightforward and viable approach for the quality control of polysaccharides.Scope and approachIn this review, special techniques for the structural characterization of LBPs are summarized and discussed. In addition, quality evaluation approaches of LBPs that have never been emphasized are highlighted herein. Furthermore, industrial applications of LBPs are reviewed and discussed.Key findings and conclusionsHigh-performance anion-exchange chromatography coupled with pulsed amperometric detection is one of the most effective techniques for analysis of both acidic and neutral LBPs. Size-exclusion chromatography coupled with multi-angle laser light scattering and refractive index detection is able to determine absolute molecular weights, chain conformations, and contents of LBPs. Fingerprinting analysis and saccharide mapping analysis are effective approaches for quality evaluation of LBPs. However, the lack of appropriate quality evaluation approaches indicates an unreliable regulation of LBPs and their related products. This reveals the deficiency in the quality control of commercial products. Thus, the development of reliable approaches for pharmacological activity-based quality control of LBPs and their related products must be extensively investigated.     

柱前衍生化高效液相色谱法测定荞麦中D-手性肌醇含量的方法

建立了一种柱前衍生化高效液相色谱法(HPLC)测定荞麦中D-手性肌醇(D-CI)含量的方法,对衍生化试剂及方法的重复性、稳定性、精密性及加标回收率进行了考察。得到衍生化条件为:苯甲酰氯0.2 mL,吡啶0.6 mL,反应温度70℃,反应时间60 min;色谱条件为:C18柱(4.6 mm×250 mm,5 μm),以乙腈和超纯水为流动相进行梯度洗脱,流速为1.0 mL/min,柱温30℃,UV检测波长230 nm。结果表明,荞麦中的D-CI获得了很好的分离,D-CI在0.004~0.04 mg/mL内线性相关性好,R2为0.999,加标回收率为98.40%~100.67%,所建立的方法稳定、灵敏、重现性好,可用于测定荞麦中D-CI含量定量分析。     

顶空-气相色谱法测定亚麻籽油中溶剂残留量的不确定度分析

目的分析顶空-气相色谱法测定亚麻籽油中的溶剂残留量的不确定度。方法应用因果图分析法分析溶剂残留量测量过程的不确定度来源,通过建立数学模型量化不确定度的各主要分量,计算合成不确定度和扩展不确定度。结果当亚麻籽油中溶剂残留量为20.3 mg/kg,扩展不确定为2.0 mg/kg(k=2)。影响检测结果测量不确定度的最主要因素为标准曲线拟合。结论通过分析评定测量不确定度,能够有效掌握实验测定结果的准确性和可信度,确保检验工作的质量。