在线扫集-胶束电动毛细管色谱法对活血通脉片中阿魏酸与原儿茶醛的分离测定

建立了在线扫集-胶束电动毛细管色谱法同时分离测定活血通脉片中阿魏酸和原儿茶醛含量的方法。讨论了pH值、十二烷基磺酸钠(SDS)浓度、电压、有机溶剂、进样时间和背景电解质组成对分离效果的影响。结果表明:采用未涂层熔融石英毛细管,以20 mmol/L磷酸二氢钠、140 mmol/LSDS为电泳缓冲液(含16%甲醇,pH2.2),在优化条件下,阿魏酸和原儿茶醛在19 min内出峰,峰面积RSD均小于5%,其线性范围分别为0.67~21.4、0.72~23 mg/L,回收率分别为94%~108%、91%~106%,检出限(S/N=3)分别达55.5、34.8μg/L。与胶束电动毛细管色谱相比,在线扫集-胶束电动毛细管色谱分离效果稳定,重现性好。该方法用于活血通脉片中阿魏酸、原儿茶醛含量的测定,结果满意。     

高效液相色谱/质联用测定大鼠血浆中双丹方活性成分

运用LC/MS联用技术,建立同时测定大鼠血浆中丹参素、原儿茶醛、芍药苷和丹皮酚4种活性成分的分析方法。在Agilent XDB-C8柱上,以乙腈-水-0.1%醋酸为流动相,流速0.6mL/min,柱温35℃,梯度洗脱于26min内完成分析。采用选择离子监测(SIM)方式,同时以负离子模式检测丹参素、原儿茶醛、芍药苷及正离子模式检测丹皮酚。该方法简单,准确,灵敏度和专属性较好。日内精密度和日间精密度分别小于5.2%和9.9%。据此研究大鼠口服双丹方提取物后10h内血浆中上述4种物质的含量变化,结果表明:丹参素和原儿茶醛浓度在30min达到峰值,而芍药苷与丹皮酚浓度分别在60min及20min达到峰值。     

近红外光谱法快速测定溶剂型木器涂料中甲苯、乙苯和二甲苯

建立了使用近红外光谱法(NIR)快速测定溶剂型木器涂料中甲苯、乙苯和二甲苯的方法。收集涂料样品,使用气相色谱法(GC)测定苯系物含量。采用聚乙烯密实袋封装聚氨酯类、硝基类或醇酸类涂料,应用积分球透漫射采样方式采集清漆和漫射采样方式采集色漆的近红外光谱。采用偏最小二乘法,分别建立清漆和色漆的近红外光谱与苯系物线性关系模型。校正集均方差在0.43%~1.32%之间、相关系数R在0.9046~0.9766之间。验证集均方差在0.591%~1.73%之间。对未知样品预测,清漆样品预测值相对偏差<15%;色漆样品预测值相对偏差<20%。两个定量模型预测效果良好。该2个NIR定量方法适用于对溶剂型木器涂料中甲苯、乙苯和二甲苯含量进行快速测定。     

基于网格搜索的参数优化方法用于鱼粉灰分的近红外LSSVM定量分析

采用近红外(NIR)光谱技术和最小二乘支持向量机(LSSVM)参数优化方法,建立定标预测模型测定鱼粉灰分的含量,采用去趋势校正和标准正交校正(DC-SNV)相结合的方式进行光谱预处理,基于网格搜索法建立LSSVM的参数优化模型,提高NIR光谱定量分析的预测精度。结果表明,LSSVM参数网格搜索方法能够有效地应用于鱼粉NIR光谱模型优化,获得的鱼粉灰分的光谱预测值与化学测定值能较准确的匹配,有利于NIR光谱技术快速检测在养殖饲料产品中的应用。     

应用近红外光谱和偏最小二乘回归法预测玉米中淀粉含量

以普通玉米籽粒为试验材料,应用偏最小二乘回归法建立了基于近红外光谱数据的测定玉米籽粒中淀粉含量的校正模型。校正模型的校正误差（RMSEC）、交叉检验误差（RMSECV）和预测误差（RMSEP）分别#30．31％、0．42％和0．29％,校正数据集和独立的检验数据集的预测值与实际测定值之间的相关系数分别达到0．9255和0．9310,表明所建立的校正模型具有较高的预测精度和较好的推广性,为玉米籽粒中淀粉含量的快速、无损测定提供了新的途径：     

方法及标准品的选择对总酚含量测定的影响

研究不同方法及标准品对总酚含量测定的影响。采用福林酚法、普鲁士蓝法和酒石酸亚铁法为测试方法,分别以没食子酸、单宁酸、原花青素、表儿茶素等化合物为标准品,考察其对总酚含量测定的影响。结果表明,不同方法及标准品对总酚含量的测定结果有明显影响。福林酚法的最适标准品为单宁酸,其测定的样品总酚含量为22.67±0.34 mg/g;普鲁士蓝法的最适标准品为原花青素,其测定的样品总酚含量为16.12±1.32 mg/g;酒石酸亚铁法的最适标准品为单宁酸,其测定的样品总酚含量为12.19±0.27 mg/g。福林酚法的总酚测定结果高于普鲁士蓝法和酒石酸亚铁法;在总酚测定中更推荐使用普鲁士蓝法。     

近红外光谱快速测定红花逆流提取过程中羟基红花黄色素A的含量

采用近红外光谱(NIRS)透射法对红花罐组式逆流提取过程中羟基红花黄色素A(Hydroxysafflor yellow A,HSYA)的含量进行快速无损的测定.在红花逆流提取过程中,以高效液相色谱法(HPLC)为对照分析方法,测定提取液中羟基红花黄色素A的含量,运用偏最小二乘(PLS)法建立NIR光谱与羟基红花黄色素A的HPLC分析值之间多元校正模型,并对逆流提取过程的未知样本进行含量预测.校正模型相关系数达到0.982,预测相关系数达到0.965,RMSEC和RMSEP分别为0.053和0.075,RSEC和RSEP分别为3.96%和5.25%.结果表明,NIRS可以作为一种准确、快速、无损的检测方法用于检测中药逆流提取过程有效成分含量变化规律.     

近红外光谱法快速测定柴胡提取过程中的药效成分

利用近红外光谱(NIRS)技术对柴胡提取过程中的药效成分进行快速定量分析。共收集126个柴胡提取液样品,采用紫外-可见分光光度法测定总黄酮和多糖的含量,高效液相色谱法(HPLC)测定柴胡皂苷A及柴胡皂苷D的含量,以透射模式采集提取液的近红外光谱,运用偏最小二乘法(PLS)分别建立了近红外光谱与4种药效指标参考值之间的定量校正模型,并采用不同的预处理方法、光谱波段和主因子数对模型进行优化。结果表明,总黄酮、多糖、柴胡皂苷A和柴胡皂苷D 4种定量模型的近红外预测值与参考值之间的拟合性良好,模型预测精度较高,其中预测集相关系数(RP)均大于0.9;预测集误差均方根(RMSEP)分别为3.46 μg/mL、0.743 mg/mL、1.53 μg/mL、0.406 μg/mL;预测集相对偏差(RSEP)分别为1.65%、8.28%、5.74%、7.52%。该研究证实了NIRS结合PLS可成功应用于监测柴胡提取液中药效成分的含量变化,且方法具有快速、准确、无损和环保的特点。     

在线扫集-胶束毛细管电动色谱法分离测定急支糖浆中阿魏酸、原儿茶醛和原儿茶酸北大核心CSCD

本文采用扫集-胶束毛细管电动色谱法(Sweeping-MEKC)分离测定急支糖浆中的阿魏酸、原儿茶醛和原儿茶酸。采用未涂层熔融石英毛细管(50cm×50μm,有效柱长36cm),环境温度25℃,缓冲体系为20mmol/L NaH2PO4+80mmol/L十二烷基磺酸钠(SDS)+12.5%乙腈(V/V)(pH=2.2),紫外检测波长225nm,运行分离电压-20kV,进样时间60s,达到最佳的分离效果。在优化条件下,阿魏酸、原儿茶醛和原儿茶酸均在15min内出峰,峰面积的相对标准偏差(RSD)均小于5%,检出限分别为109.95μg/L、88.48μg/L和15.96μg/L。     

近红外光谱法测定涂料稀释剂中苯系物含量

建立使用近红外光谱法(NIR)快速测定溶剂型木器涂料稀释剂中甲苯、乙苯、对二甲苯、间二甲苯和邻二甲苯等苯系物含量方法。收集涂料稀释剂样品,使用气相色谱法(GC)测定苯系物含量,并采集其近红外光谱信息,采用偏最小二乘法(PLS)建立NIR光谱与苯系物含量的线性关系模型。苯系物校正均方差(RMSEC)在(0.47~1.40)%之间、相关系数(R2)在0.956~0.988之间;预测均方差(RMSEP)在(0.73~2.32)%之间、相关系数(R2)在0.951~0.986之间。NIR模型预测效果良好,定量方法快速、简单、准确,可在检测涂料的有毒有害物质中推广应用。     

Composition of structural carbohydrates in biomass: precision of a liquid chromatography method using a neutral detergent extraction and a charged aerosol detector

We adapted and optimized a method to quantify the cellulose, hemicellulose, xylan, arabinan, mannan, galactan contents in lignocellulosic biomass. This method is based on a neutral detergent extraction (NDE) of the interfering biomass components, followed by a sulfuric acid hydrolysis (SAH) of the structural polysaccharides, and a liquid chromatography with charged aerosol detection (LC-CAD) to analyze the released monosaccharides. The first step of this NDE-SAH-LC-CAD method aims at removing all compounds that interfere with the subsequent sulphuric acid hydrolysis or with the subsequent chromatographic quantification of the cellulosic and hemicellulosic monosaccharides. This step includes starch hydrolysis with an analytical thermostable α-amylase followed by an extraction of soluble compounds by a Van Soest neutral detergent solution (NDE). The aim of this paper was to assess the precision of this method when choosing fiber sorghum (Sorghum bicolor (L.) Moench), tall fescue (Festuca arundinacea Schreb.) and fiber hemp (Cannabis sativa L.) as representative lignocellulosic biomass. The cellulose content of fiber sorghum, tall fescue and fiber hemp determined by the NDE-SAH-LC-CAD method were 28.7 ± 1.0, 29.7 ± 1.0 and 43.6 ± 1.2 g/100 g dry matter, respectively, and their hemicellulose content were 18.6 ± 0.5, 16.5 ± 0.5 and 14.5 ± 0.2 g/100 g dry matter, respectively. Cellulose, mannan and galactan contents were higher in fiber hemp (dicotyledon) as compared to tall fescue and fiber sorghum (monocotyledons). The xylan, arabinan and total hemicellulose contents were higher in tall fescue and fiber sorghum as compared to fiber hemp. The precision of the NDE-SAH-LC-CAD method was better for polysaccharide concentration levels above 1 g/100 g dry matter. Galactan analysis offered a lower precision, due to a lower CAD response intensity to galactose as compared to the other monosaccharides. The dispersions of the results (expanded uncertainty) of the NDE-SAH-LC-CAD method were smaller as compared to the Van Soest (VS) method. In addition, the NDE-SAH-LC-CAD method was able to provide additional information on the composition of the hemicellulose (xylan, arabinan, mannan and galactan content) that is not provided by the Van Soest method. The NDE-SAH-LC-CAD method offers also the advantage of a better specificity for hemicellulose and cellulose, as compared to the NREL and Uppsala methods.     

溶剂浮选-紫外分光光度法测定厚朴中总厚朴酚

建立了一种测定厚朴中总厚朴酚的新方法,即采用溶剂浮选法分离富集厚朴中的总厚朴酚,用紫外分光光度法测定其含量。考察了浮选溶剂、试液pH、氮气流速、浮选时间及电解质NaCl等因素对浮选效果的影响,优选出最佳浮选条件。采用所述方法对不同产地厚朴样品中总厚朴酚含量进行测定,样品加标回收率为94.9%-100.8%,RSD为2.8-4.1%。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定镧玻璃废粉中稀土元素总量及配分量

建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定镧玻璃废粉中稀土元素总量和配分量的分析方法。样品经碱熔融后分离硅、铝等元素及钠盐,用硝酸和高氯酸破坏滤纸和溶解沉淀,用ICP-AES法测定稀土元素总量和配分量。讨论了溶解样品条件、共存元素干扰等影响测定的各种因素。实际样品的稀土总量与草酸盐重量法测定结果一致,配分量与X-射线荧光光谱(XRF)法、电感耦合等离子体质谱(ICP-MS)法测定结果一致。RSD(n=11)在0.15%~1.1%,加标回收率为97%~105%。测定范围为:La_2O_3/REO(80%~98%);CeO_2/REO(2%~20%);REO(16%~70%)。方法能快速准确地测定镧玻璃废粉中稀土元素总量及配分量。     

The Effects of Processing on Bioactive Compounds and Biological Activities of Sorghum Grains

Sorghum is ranked the fifth most commonly used cereal and is rich in many kinds of bioactive compounds. Food processing can affect the accumulation and decomposition of bioactive compounds in sorghum grains, and then change the biological activities of sorghum grains. The present review aims to analyze the effects of processing technologies on bioactive compounds and the biological activities of sorghum grains. Decortication reduces the total phenols, tannins, and antioxidant activity of sorghum grains. The effects of thermal processes on bioactive compounds and potential biological activities of sorghum grains are complicated due to thermal treatment method and thermal treatment conditions, such as extrusion cooking, which has different effects on the bioactive compounds and antioxidant capacity of sorghum due to extrusion conditions, such as temperature and moisture, and food matrices, such as whole grain and bran. Emerging thermal processes, such as microwave heating and high-pressure processing, could promote the release of bound phenolic substances and procyanidins, and are recommended. Biological processes can increase the nutritive and nutraceutical quality and reduce antinutritional compounds, except for soaking which reduces water-soluble compounds in sorghum.     

钛粉质量鉴定新方法试验研究

钛粉质量鉴定一直是用化学分析测定全钛含量，而不能确定单质态的钛含量，实验表明用Ｘ射线衍射分析鉴定钛粉质量效果较好，避名了化学分析的缺点，是一种值得推广的鉴定方法。     

Characterization and phytoavailability evaluation of micronutrients and contaminants in some Brazilian phosphate fertilizers

Brazilian fertilizer legislation considers the total concentration of micronutrients as being the guarantee of their presence in fertilizers. This fact allows the use industrial by-products as micronutrient source for fertilizers, which brings the risk of the presence of high amounts of toxic elements that may lead to soil contamination. The purpose of this study was to determine the micronutrient and contaminant contents in six Brazilian commercial phosphate fertilizers and to evaluate the phytoavailability of elements from soils treated with these fertilizers. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine the contents of the elements. As, Cd, Co, Cr, Fe, Mo, Na, Sb and Zn were detected in fertlizers. Concentrations in vegetal tissue were not modified by the treatments, except for Cd, which was increased due to fertilizers application.     

西南山地煤矿区耕地土壤-农作物重金属富集及健康风险评价

为了解西南某典型山地煤矿区周边农田土壤、农作物重金属的富集情况及对当地人群健康的影响程度,采集矿区周边农田土壤样品和对应的农作物样品,测定重金属Cr、Mn、Zn、As、Pb的含量。运用Nemero指数法、潜在风险指数法对土壤重金属的污染程度进行评价;采用靶标危害系数法(THQ)评价农作物重金属对人体的健康风险。结果显示,Cr、Mn、Zn、As、Pb分别是背景值的1.81、1.90、2.89、1.30、0.86倍,处于轻度污染级别,轻微危害程度。农作物重金属Cr、Pb和As含量的超标情况较严重,Zn的含量超标相对较小。各农作物富集的重金属对人体的健康风险大小为：高粱>玉米>白菜>葱>辣椒。农作物重金属对儿童健康的危害均达到了慢性中毒;对成人健康的影响,高粱处于慢性中毒,其它农作物重金属处于产生较大影响的危害程度。农作物重金属与土壤重金属的相关性分析表明,农作物重金属的含量与土壤重金属全量并无线性关系;各重金属在农作物中的转移能力不同;Pb,As在农作物中的转移能力较大,而Cr相对较小。鉴于矿区重金属的富集情况,应尽快采取修复治理措施,为保证当地人群健康,建议当地居民不再食用和种植富集重金属严重的高粱、玉米农作物。     

Multivariate optimization of solvent extraction with 1,1,1-trifluoroacetylacetonates for the determination of total and labile Cu and Fe in river surface water by flame atomic absorption spectrometry

A procedure for simultaneous solvent extraction of Cu(II) and Fe(III) from river surface waters as diethyldithiocarbamates (DDC) 1,1,1-trifluoroacetylacetonates into isobutyl methyl ketone (IBMK) has been developed prior to their determination by flame atomic absorption spectrometry. Experimental design approaches were used in order to obtain the best compromise conditions for simultaneous solvent extraction. Variables such as pH, sodium DDC or 1,1,1-trifluoro-2,4-pentanodione (H(TFA)) concentrations, reaction time, IBMK volume and extraction time have been optimized. First, Plackett–Burman designs involving 13 experiments and 2 replicates were used as screening designs to determine which variables were significant. DDC or H(TFA) concentration, as well as pH and IBMK volume were found statistically significant and they were finally optimized by applying a central composite design (15 experiments and 2 replicates). Optimum values for these variables were selected for compromise extraction conditions of Cu(II) and Fe(III) species. An optimum pH of 5.3 was chosen for Cu–H(TFA) and Fe–H(TFA) formation with an optimum H(TFA) concentration of 0.20% (m/v). The optimum IBMK volume for extraction was 8 ml, allowing a pre-concentration factor of 10. A microwave-assisted peroxydisulfate oxidation was used to break down the metal–organic matter complexes in river surface waters in order to assess the total Cu and Fe contents. Applying the experimental design approach, optimum conditions was an irradiation for 5.0 min at a microwave power of 500 W using 0.5 g of ammonium peroxydisulfate. The method was applied to determine total Cu and Fe contents and also labile Cu(II) and Fe(III) contents in several river surface water samples.     

Photocontrol of organelle and cell type specific changes in the polypeptide composition of Euglena and sorghum

Two-dimensional (2-D) gel electrophoresis has been used to follow changes in cell type specific and organelle localized polypeptides upon exposure of etiolated sorghum shoots and dark-grown resting Euglena to light. Total protein extracted from isolated bundle sheath strands and mesophyll protoplasts was resolved by 2-D gel electrophoresis. The cell type specific polypeptides were localized on the whole shoot 2-D gel map in order to determine changes in the levels of these polypeptides upon light exposure. An image analyzer was used to analyze fluorographs of 2-D gels of total Euglena protein pulse-labeled with [35S]sulfate in the dark, immediately upon light exposure and 1, 4, 14, 24, 48 and 72 h after light exposure. The subset of polypeptides whose relative rate of synthesis changes more than threefold immediately upon light exposure was identified. The different patterns of changes in the rate of synthesis of this subset of polypeptides were followed.     

人体胎盘合体滋养细胞质膜的脂肪酸组成分析

用Ｗｈｉｔｓｅｔｔ法提取１８只正常足月妊娠分娩的胎盘合体滋养细胞质膜（ＳＰＭ）,采用Ｌａｎｄｏｎ法提取脂质,使用气相色谱法和丁二酸二乙二醇酯（ＤＥＧＳ）填充柱分离测定ＳＰＭ的脂肪酸,结合气相色谱／质谱定性,将１３种碳数大于１４的脂肪酸进行了定性和定量。定量出的脂肪酸占出峰物质总量的７４．１％,其中饱和脂肪酸为３０．６４％,不饱和脂肪酸为４３．４６％。