表面活性剂增强铈-对乙酰氨基酚化学发光测定对乙酰氨基酚片

本文研究了表面活性剂对铈(Ⅳ)氧化对乙酰氨基酚化学发光反应的影响,发现了铈(Ⅳ)-吐温20-对乙酰氨基酚化学发光新体系,建立了测定对乙酰氨基酚化学发光的分析方法。在0.1 mol/L的H2SO4介质下,0.06 mol/L的硫酸高铈载液中,对乙酰氨基酚的浓度在8.0×10-8~1.0×10-4mol/L范围内与发光强度成良好的线性关系(r=0.9992,n=13),检出限为4.0×10-8mol/L。连续测定2.0×10-6mol/L的AP溶液7次,发光强度的RSD为1.0%。此方法简单、方便、灵敏,适合于在线分析。该法用于对乙酰氨基酚药片中对乙酰氨基酚的测定。     

RP-HPLC梯度洗脱法测定桑叶中芦丁和绿原酸的含量

建立了同时测定桑叶中芦丁和绿原酸含量的方法,采用Kromasil C18柱(4.6 mm×250mm,5μm),以甲醇0.5%磷酸的水溶液为流动相,梯度洗脱程序为0 min[V(甲醇) V(0.5%磷酸)=30 70]15 min[V(甲醇) V(0.5%磷酸)=30 70]20 min[V(甲醇) V(0.5%磷酸)=50 50]35 min[V(甲醇) V(0.5%磷酸=50 50];流量0.8 mL.min-1;检测波长350 nm;柱温25℃;光电二极管阵列检测器(PAD)。结果表明,芦丁线性范围为0.218~1.962μg,r=0.999 3,样品的平均加样回收率为101.3%,RSD 1.1%;绿原酸线性范围为0.654~5.886μg,r=0.999 7,样品的平均加样回收率为98.2%,RSD 1.1%;绿原酸线性范围为0.654~5.886μg,r=0.999 7,样品的平均加样回收率为98.2%,RSD1.5%。该法快速简便,专属性强,重复性好,可作为桑叶中芦丁的定量分析方法。     

高效液相色谱化学发光检测法测定食品中苏丹红Ⅰ

基于碱性条件下,苏丹红Ⅰ对鲁米诺-KIO4发光体系的增敏作用,建立了高效液相色谱化学发光测定苏丹红Ⅰ的新方法。方法采用Phenomenex C18色谱柱(250×4.6mm,5μm),以乙腈∶甲醇∶水=5∶4∶1(V/V/V)为流动相,在0.001～0.50μg/mL范围内,苏丹红Ⅰ浓度与发光强度呈良好的线性关系,相关系数为0.9996,检出限为5ng/kg,相对标准偏差为1.45%(c=0.01μg/mL,n=6),加标回收率为95.0%～104.0%。该法灵敏、准确,用于实际样品中苏丹红Ⅰ的测定,结果令人满意。     

苏丹红Ⅰ-甲醇体系的共振光散射光谱研究及其应用

研究了苏丹红Ⅰ-甲醇体系的共振光散射(RLS)光谱和作用机制,建立了测定苏丹红Ⅰ的RLS新方法。温度20℃时,苏丹红Ⅰ-甲醇体系的RLS强度降低值(△I)与苏丹红Ⅰ的浓度在0.5~16.0μg/mL具有良好的线性关系,方法检出限0.16μg/mL,相对标准偏差(RSD)为1.8%~2.4%(n=11),加标回收率为92.7%~103.8%。     

高效液相色谱法测定抗癌原料药芳香异羟肟酸二丁基锡

建立了反相高效液相色谱法测定有机金属抗癌原料药芳香异羟肟酸二丁基锡. 色谱条件: Diamonsil ODS 色谱柱 (4.6 mm i.d.×200 mm, 5 μm), 以V(甲醇)∶V(水)＝35∶65, pH 2.5为流动相, 流速为1.0 mL/min, 紫外检测波长232 nm, 柱温25 ℃. 吲达帕安为内标测定芳香异羟肟酸二丁基锡. 结果表明: 线性范围为4.08～102 μg/mL, 回归方程为f=0.02253ρ-0.005843, r=0.9998 (n=7), 方法精密度RSD为0.89% (n=6), 稳定性的RSD为0.56% (n=9), 重复性的RSD为0.90% (n=9), 平均回收率为100.5% (n=9, RSD=1.1%). 方法可用来测定芳香异羟肟酸二丁基锡.     

高效液相色谱法同时测定血清和尿中厚朴酚与和厚朴酚

 建立了大鼠服用厚朴提取物后的血清中及尿中厚朴酚与和厚朴酚的高效液相色谱测定法。色谱柱填料为SpherisorbC18,流动相为甲醇-水-冰醋酸(体积比为70∶30∶1),UV检测波长为294nm,灵敏度0.005AUFS。样品用甲醇沉淀蛋白,上清液酸化后用乙酸乙酯-乙醚萃取,然后测定其中的药物浓度。血清和尿中的药物浓度与峰面积的线性关系良好,线性范围分别为0.05～2mg/L(厚朴酚)、0.025～1mg/L(和厚朴酚);精密度和重现性良好。血清中厚朴酚与和厚朴酚的平均加样回收率分别为95.6%(RSD=3.85%)和93.8%(RSD=3.95%),尿中分别为96.0%(RSD=3.83%)和94.9%(RSD=3.54%)。     

反相高效液相色谱同时测定五味子中五味子醇甲、五味子酯甲和五味子乙素的含量

本文建立了同时测定五味子中五味子醇甲、五味子酯甲和五味子乙素的反相高效液相色谱(RP-HPLC)方法。五味子先经超声提取后用高效液相色谱法测定。色谱柱为Kromasil C18柱(150×4.6 mm,5μm),流动相为甲醇-水(75∶25,V/V),紫外检测波长220 nm,柱温30℃,流速1.0 mL/min。结果显示,五味子醇甲在0.10~6.0μg范围内(r=0.9998),五味子酯甲在0.13~8.0μg范围内(r=0.9999),五味子乙素在0.03~2.0μg范围内(r=0.9999)线性关系良好。平均回收率五味子醇甲为98.6%,相对标准偏差(RSD)为1.4%(n=5);五味子酯甲为97.1%,RSD为1.6%(n=5);五味子乙素为97.7%,RSD为1.1%(n=5)。本法准确、快速、灵敏度高,可用于五味子中有效成分的定量分析。     

发酵液中香兰素的反相高效液相色谱分析方法研究

建立了测定发酵液中香兰素含量的反相高效液相色谱方法。采用Symmetry C18柱(5μm,4.6 mm i.d.×150 mm),以V(甲醇)∶V(水)=35∶65为流动相,流速为1.0 mL/min,紫外检测波长为280 nm,柱温为室温,进样量10μL。香兰素在5.0~1000 mg/L范围内,峰面积与质量浓度呈良好的线性关系,相对标准偏差RSD为0.68%,回收率在99.88%~100.28%之间。该方法适用于微生物发酵法合成香兰素的质量控制及发酵工艺的改进。     

流动注射电化学还原-化学发光法测定铀

采用恒电位电解技术,使不具发光活性的铀(Ⅵ),通过自制的流通式碳电解池后,在-0.70 V(vs,Ag/AgCl)电位下在线还原为铀(Ⅲ),铀(Ⅲ)与鲁米诺在碱性条件下产生化学发光,从而建立了铀的流动注射电化学发光分析法。方法的线性范围为1.0×10-6~1.0×10-2g.L-1,检出限2×10-7g.L-1,RSD为2.5%(n=13)。该方法用于合成海水中铀的测定,回收率为98.0%~103.3%。     

流动注射化学发光法测定醋氯芬酸

基于酸性条件下醋氯芬酸对高锰酸钾氧化甲醛产生微弱化学发光反应体系具有很强的增敏作用,且增强的发光强度在一定范围内与醋氯芬酸浓度呈良好的线性关系,结合流动注射分析技术,建立了测定醋氯芬酸的化学发光新方法。该法测定醋氯芬酸的线性范围为0.08~5.0 mg/L,检出限(3σ)为3.0×10-2mg/L,相对标准偏差(RSD)为1.7%(n=11,c=0.50 mg/L),回收率为98.1%~104.6%。该法已用于片剂和胶囊中醋氯芬酸含量的测定。     

On-line enantiomeric analysis using high-performance liquid chromatography in chiral separation by simulated moving bed

An automated on-line enantiomeric analysis system comprising an analytical HPLC set-up with two UV detectors sharing the same light source has been employed to monitor the internal composition profile in chiral simulated moving bed chromatography. This monitoring scheme does not use a polarimeter. Using a sampling interface placed between two SMB columns, effluent samples are directed onto a high-efficiency analytical column at a sampling rate faster than the overall dynamics of the preparative unit to achieve on-line enantiomeric analysis of the composition profile. The other UV detector is placed in the SMB loop before the fraction collector to provide instantaneous measurement of the total enantiomeric concentration. The feasibility and effectiveness of the on-line enantiomeric monitoring scheme were assessed experimentally on the separation of Tr?ger's base racemate, using Chiralpak AD as stationary phase and methanol as eluent. It was found that robust monitoring of the concentration profiles of the individual enantiomers is best achieved when the enantiomeric purity obtained from the peak areas of the on-line enantiomer analysis chromatograms is combined with the on-line UV measurement of total enantiomeric concentration. The accuracy and robustness of the proposed on-line enantiomeric monitoring system open up promising perspectives for process control and dynamic optimization of the SMB.     

流动注射双合并带铬黑T-Ca(Ⅱ)络合消光光度法监测葡萄糖酸亚铁合成

开发了一种基于流动注射双合并带铬黑T(EBT)-Ca(Ⅱ)络合消光光度法在线监测葡萄糖酸亚铁(Fe-Gla)合成的FIA系统,依据葡萄糖酸钙(Ca-Gla)、Fe(Ⅱ)型树脂为原料合成Fe-Gla的离子交换反应式(Ca(Ⅱ)+RFe■RCa+Fe(Ⅱ)),通过检测合成过程中的Ca(Ⅱ),实现了对Fe(Ⅱ)型树脂柱运行状态及产品中Fe-Gla含量的自动在线监测。对该系统的相关影响因素进行了优化:检测波长为660 nm、EBT浓度为280 mg/L、载流为NH3·H2O/NH4Cl(pH 12.4)的混合液。本方法测定Ca(Ⅱ)的线性范围为0~640 mg/L,对合成过程进行监测时,896 mg/L Fe(Ⅱ)、64 mmol/L H+对监测结果无影响。本方法实现了产品生产实时自动化监测分析,具有人为误差小、精度高(RSD≤0.53%,n=11)、分析速度快、试剂/试样用量少等特点。     

On-line-Bestimmung von Enzymen in der Bioproze?analytik unter Berücksichtigung von Probenahme und Flie?injektionstechnik

Summary The on-line determination of enzymes in biotechnical processes becomes an important factor with regard to process development and optimization. At present, most commonly enzymes are determined off-line in the laboratory after withdrawal of a separate sample. Wet chemical methods dominate in this respect, mainly because enzymes have to be measured according to the reaction schemes which are catalyzed by them. For an efficient process monitoring and control the time delay, the limited reliability and the man power needed for analysis of a large number of samples are crucial points. By using the technique of flow injection analysis (FIA) it should in general become easy to develop automatically operated enzyme determination procedures based on reaction schemes which can be used for fast and efficient process monitoring, providing the problems with the coupling of the analyzer at the bioreactor are solved. Continuous sampling in this respect plays a key role in developing on-line measuring techniques. This paper reviews the current status of on-line enzyme analysis, using flow-injection techniques. It is shown that the coupling problems can be solved by using a newly developed sampling module, which is based on membrane filtration. Some examples of on-line enzyme determinations in fermentation as well as in downstream processing illustrate the ease and reliability of the proposed concept for using FIA in connection with membrane separation.     

Optimization of Saccharification and Fermentation Process in Bioethanol Production from Oil Palm Fronds

Oil Palm Frond (OPF) is one of lignocellulosic biomass, which can be utilized as raw material for bioethanol production. Bioethanol is produced as alternative energy to substitute gasoline. There are four steps in bioethanol production from OPF, i.e pretreatement, saccharification, fermentation and purification process. In this study, optimization of saccharification and fermentation process for OPF was investigated. Two methods and the variations of enzyme concentration were carried out in the saccharification and fermentation process. Separate hydrolysis and fermentation process (SHF) and simultaneous saccharification and fermentation process (SSF) were conducted to produce ethanol optimally. Variations of enzyme concentration used in this process were 10, 20, 30 and 40 FPU/g substrate. The result shows that the highest ethanol concentration can be obtained in SSF process with 30 FPU/g substrate of enzyme concentration. The process produced 59.20 g/L ethanol (95.95% yield ethanol) at 96 h of SSF process.     

在线固相萃取/液相色谱-线性离子阱质谱法同时检测生物样品中18种氨基甲酸酯类农药

建立了同时测定全血、尿液和肝组织等生物样品中18种氨基甲酸酯类农药的在线固相萃取/液相色谱-线性离子阱质谱(On-line SPE/LC-LIT/MS)分析方法。样品经乙腈处理,稀释和离心后直接进样。经Waters OasisHLB在线SPE柱富集纯化,以BETASIL C18柱为分析柱,甲醇-水(均含0.1%甲酸)为流动相进行梯度洗脱;使用电喷雾电离(ESI)正离子模式测定,扫描方式为选择反应监测(SRM)和连续反应监测(CRM)。18种农药在考察的质量浓度范围内线性关系良好(权重因子1/X),相关系数为0.994 3~0.999 4;在全血和尿液中的检出限为0.1~5 ng/m L,在肝组织中的检出限为0.1~5 ng/g;3个加标水平的回收率为90.2%~114.5%,相对标准偏差(n=4)为0.5%~7.5%。该方法简单准确,灵敏度高,能够满足生物样品中18种氨基甲酸酯类农药的快速分析要求。     

Peroxidase enzyme sensor for on-line monitoring of disinfection processes in the food industry.

For desirable environmental reasons, peroxides have replaced halogenated substances for disinfection purposes in the food and beverage industry. However, cost issues and the requirement to remove these agents completely after disinfection necessitate simple, low-cost and sensitive test methods with a wide dynamic range and on-line capability. The development and performance of such a method is detailed here. Low-cost peroxide sensors were fabricated using a single deposition procedure, in which horseradish peroxidase enzyme and dimethylferrocene mediator were entrapped within a cellulose acetate membrane, over the working electrode area of a screen-printed three-electrode assembly. Optimum performance was obtained using HRP and DMFc loadings of 25 U and 0.03 micromol per electrode, respectively, and a mean cellulose acetate molecular weight of 37,000. The device had a detection limit of 49.5 microM hydrogen peroxide and mean RSD values of 21% across the concentration range 49.5-368 microM. In laboratory studies the sensor was shown to have a stability of > or = 4 d in continuous flow-mode maintaining an accuracy of +/- 16% that was considered acceptable for the intended on-line monitoring of the disinfection process. In a field study, it was successfully used on-line within a flow-cell to measure peroxide levels during disinfection of an industrial fermentation vessel.     

在线固相萃取结合液相色谱-线性离子阱多级质谱法同时检测生物样品中7种乌头类生物碱

建立了在线固相萃取(on-line SPE)结合液相色谱-线性离子阱多级质谱(LC-LIT/MSⁿ)同时测定全血、尿液和肝组织样品中7种乌头类生物碱的分析方法,并根据7种乌头类生物碱的多级质谱碎片对裂解规律进行了推测和总结。用乙腈沉淀样品中的蛋白质,于稀释和离心后直接进样。经Waters Oasis^® HLB在线SPE柱富集纯化,以0.1%(v/v)甲酸/乙酸铵溶液-0.1%(v/v)甲酸/甲醇溶液为流动相,以Accucore C18为分析柱进行梯度洗脱;在电喷雾电离(ESI)正离子模式下测定;扫描方式为连续反应监测(CRM)。在考察的质量浓度范围内,7种乌头类生物碱的标准曲线符合二阶方程(权重因子1/x),相关系数为0.9991~0.9999;在全血和尿液中的方法检出限为0.02~0.60 ng/mL,在肝组织中的方法检出限为0.02~0.40 ng/g;加标回收率为91.1%~104.7%,日内精密度和日间精密度分别为0.2%~10.7%、1.0%~13.7%(n=6)。该方法简单准确,灵敏度高,能够满足生物样品中7种乌头类生物碱的快速分析。     

On-line monitoring during fermentation of whey based on ultrafiltration and liquid chromatography

A high-performance liquid chromatographic (HPLC) system, controlled by means of a programmer, is described for monitoring the conversion of sugars and the formation of acids during fermentation processes. An on-line automatic sampling system was developed in order to achieve systematic sampling of the fermentation broth. The fermentor is connected to the HPLC system through a tangential ultrafiltration unit. This system is integrated into an automatic HPLC line for routine analysis.     

On-line monitoring of continuous beer fermentation process using automatic membrane inlet mass spectrometric system

A fully automatic membrane inlet mass spectrometric (MIMS) on-line instrumentation for the analysis of aroma compounds in continuous beer fermentation processes was constructed and tested. The instrumentation includes automatic filtration of the sample stream, flushing of all tubing between samples and pH control. The calibration standards can be measured periodically. The instrumentation has also an extra sample line that can be used for off-line sample collection or it can be connected to another on-line method. Detection limits for ethanol, acetic acid and eight organic beer aroma compounds were from μg l⁻¹ to low mg l⁻¹ levels and the standard deviations were less than 3.4%. The method has a good repeatability and linearity in the measurement range. Response times are shorter than or equal to 3 min for all compounds except for ethyl caproate, which has a response time of 8 min. In beer aroma compound analysis a good agreement between MIMS and static headspace gas chromatographic (HSGC) measurements was found. The effects of different matrix compounds commonly present in the fermentation media on the MIMS response to acetaldehyde, ethyl acetate and ethanol were studied. Addition of yeast did not have any effect on the MIMS response of ethanol or ethyl acetate. Sugars, glucose and xylose, increased the MIMS response of all studied analytes only slightly, whereas salts, ammonium chloride, ammonium nitrate and sodium chloride, increased the MIMS response of all three studied compounds prominently. The system was used for on-line monitoring of continuous beer fermentation with immobilised yeast. The results show that with MIMS it is possible to monitor the changes in the continuous process as well as delays in the two-phase process.     

The effect of pectinase on the bubble fractionation of invertase from α-amylase

Fermentation broth normally contains many extracellular enzymes of industrial interest. To separate such enzymes on-line could be useful in reducing the cost of recovery as well as in keeping their yield at a maximum level by minimizing enzyme degradation from broth proteases (either the desired enzymes or the proteases could be removed selectively or both removed together and then separated). Several large-scale separation methods are candidates for such on-line recovery such as ultrafiltration, precipitation, and two-phase partitioning. Another promising technique for on-line recovery is adsorptive bubble fractionation, the subject of this study. Bubble fractionation, like ultrafiltration, does not require contaminating additives and can complement ultrafiltration by preconcentrating the enzymes using the gases normally present in a fermentation process. A mixture of enzymes in an aqueous bubble solution can, in principle, be separated by adjusting the pH of that solution to the isoelectric point (pI) of each enzyme as long as the enzymes have different pIs. The model system investigated here is comprised of three enzyme separations and the problem is posed as the effect of pectinase (a charged enzyme) on the bubble fractionation of invertase (a relatively hydrophilic enzyme) from α-amylase (a relatively hydrophobic enzyme). The primary environmental variable studied, therefore, is the pH in the batch bubble fractionation column. Air was used as the carrier gas. This prototype mixture exemplifies an aerobic fungal fermentation process for producing enzymes. The enzyme concentration here is measured as total protein concentration by the Coomassie Blue (Bradford) solution method (1), both as a function of time and column position for each batch run. Since, from a previous study (2), it was found that invertase and α-amylase in a two-enzyme system can be partially separated in favor of one vs the other at two different pHs (pH 5.0 and 9.0) with significant separation ratios, emphasis is placed on the effect of pectinase at these pHs. In this study, the addition of pectinase reduced the total separation ratio of the α-amylase-invertase mixture at both pHs.