毛细管气相色谱法测定面粉中的过氧化苯甲酰

采用毛细管气相色谱法测定面粉中过氧化苯甲酰的含量。方法的线性范围为0.0-500.0μg/mL,检出限为1.0ng,RSD为0.564%-0.906%,回收率为92.7%-101.3%。该法可用于面粉质量的监测。     

Determination of selected persistent organochlorine pollutants in human milk using solid phase disk extraction and narrow bore capillary GC-MS

Summary A simple and rapid procedure based on solid phase disk extraction (SPDE), adsorption chromatography on acidified silica gel and GC-MS analysis was developed for the determination of 8 organochlorine pesticides and 19 PCB congeners in human milk. By using the SPDE procedure, a high throughput and parallel sample processing could be achieved. Method variables were optimized on whole cow's milk (3.5% fat) fortified at levels close to concentrations found in human milk. Recoveries of target analytes were acceptable and ranged from 69 to 102% and 86 to 120% for whole and skimmed milk, respectively. By the use of two stage clean-up and narrow bore capillary columns, detection limits as low as 20 pg mL⁻¹ could be obtained. The method was used for the determination of organochlorine pollutants in human milk from 19 individuals from Romania. The concentrations of PCBs were low, whereas those of organochlorine pesticides were higher than the values reported from other European countries.     

环糊精毛细管区带电泳分离手性药物对映体

分别以2种天然环糊精(β、γ-环糊精)、2种常用的电中性环糊精衍生物(羟丙基-β-环糊精、二甲基-β-环糊精)和3种新型荷电环糊精衍生物(高取代磺酸基α、β、γ-环糊精)作为毛细管区带电泳手性添加剂,研究了环糊精的类型对6种手性药物对映体分离的影响.2种天然环糊精对所研究的手性药物均无手性识别能力,而环糊精经过衍生化后手性识别能力得到了很大的提髙,尤其是高取代磺酸基β-环糊精使6种手性药物均得到了基线分离.还考察了缓冲溶液的pH值和有机添加剂对手性分离的影响.     

新型安培检测毛细管电泳微系统

将电极、６ｃｍ分离毛细管、缓冲池、检测池集成于８．４×５．０ｃｍ有机玻璃片上,制作了一个毛细管电泳微系统。以碳纤维微盘电极作为工作电极,采用三电极体系柱端检测了１×１０－４ｍｏｌ／Ｌ多巴胺（ＤＡ）,具有良好的重现性,检测限３．６×１０－８ ｍｏｌ／Ｌ,线性范围５×１０－７～１×１０－４ｍｏｌ／Ｌ,并在该系统上分离了邻苯二酚（ＣＡ）和多巴胺的混合物。     

毛细管电泳法测定猪体组织中甜菜碱含量

建立了毛细管电泳法快速测定猪体组织中甜菜碱含量的方法。甜菜碱首先转化为苯甲酰甲基酯后直接上样测定。pH为 3 .0的磷酸缓冲溶液使甜菜碱酯化物和甜菜碱结构类似物酯化物之间以及酯化物和酯化剂之间都能很好地分离 ,这也省去了反应混合液的前处理。该法标准曲线的线性范围为 4～ 6 0 0mg L ,相关系数r为 0 .9999,最低检测限为 1mg L ,相对标准偏差为 2 .2 %～ 4.7% ,标准加入回收率为 95 9%～ 98.4%     

衍生化毛细管气相色谱法分离测定山梨醇和甘露醇

采用乙酸酐为衍生化试剂,吡啶为溶剂和催化剂,将山梨醇和甘露醇转化成易恽发的糖醇乙酰酯衍生物。用苯基氰丙基聚硅氧烷（BPX-70）毛细管色谱柱分离分析,使同分异构体的六元糖醇得到了很好的分离,并用内标法定量。山梨醇甘露醇的线性范围均为2.50g/L-12.5g/L,检测限分别为0.60ng和0.68ng。     

不锈钢宽口径填充毛细管液相色谱柱的制备及评价

设计了一种零死体积的柱尾连接方式和一种能使匀浆填料均匀进入色谱柱管内的锥形储料池。详述了以反相 ＯＤＳ为固定相,制备高效稳定的不锈钢宽口径（０．８ ｍｍＩ．Ｄ．）填充毛细管液相色谱柱的方法。系统地考察了填装方向、加压溶剂、匀浆溶剂、匀浆浓度和填装压力等不同因素对柱效的影响。在４０ＭＰａ压强和优化条件下,可重复制得柱效达理论塔板数为７．５×１０４／ｍ。对所测试的样品,色谱峰不对称因子为１．０３～１．１０。     

Measurement of bubble size distribution in protein foam fractionation column using capillary probe with photoelectric sensors

Bubble size is a key variable for predicting the ability to separate and concentrate proteins in a foam fraction ation process. It is used to characterize not only the bubble-specific interfacial a rea but also coalescence of bubbles in the foam phase. This article describes the development of a photoelectric method for measuring the bubble size distribution in both bubble and foam columns for concentrating proteins. The method uses a vacuum to withdraw a stream of gas-liquid dispersion from the bubble or foam column through a capillary tube with a funnel-shaped inlet. The resulting sample bubble cylinders are detected, and their lengths are calculated by using two pairs of infrared photoelectric sensors that are connected with a high-speed data acquisition system controlled by a microcomputer. The bubble size distributions in the bubble column 12 and 1 cm below the interface and in the foam phase 1 cm above the interface are obtained in a continuous foam fractionation process for concentrating ovalbumin. The effects of certain operating conditions such as the feed protein concentration, superficial gas velocity, liquid flow rate, and solution pH are investigated. The results may prove to be helpful in understanding the mechanisms controlling the foam fractionation of proteins.     

杯芳烃涂层毛细管分离单胺类神经递质

本文设计制作了一种对烯丙基杯 [4 ]芳烃涂层毛细管。用于毛细管电泳分离的结果表明 ,此管能分离 5 羟色胺 ( 5 HT)、多巴胺 (DA)、去甲肾上腺素 (NE)、肾上腺素 (E)等结构相近的单胺类神经递质 ,而无涂层管则不能。本涂层管在pH4～ 9范围内的电渗较无涂层管下降约 75% ,且当pH <8时 ,电渗随pH的变化接近于线性关系 ,有利于高重现分离。杯芳烃涂层毛细管不降低紫外检测灵敏度。其主要问题是酚羟基对胺类仍有吸附 (或静电 )作用     

Key Conditions in Capillary Electrophoresis of Amino Acids with Indirect Ultraviolet Detection

Illdircct llltraviolct (UV) dclectioll is bccolllillg allractive ill capillary clectroplloresis(CE) of alllillo acids dllC ic tile avoidallcc of tillle-collslllllillg derivalizatioll, and ease tobe dcvclopcd as a llllivcrsnl dclcctioll 1ilo4c'-'. Hoal'cvcr, tllcre are still problems illpractical applicatiolls. Tile 1host scriolls ollc is tile irrcprodllcible separation of tellresllltcd. We 11nvc 11cllce started a pro.icct try'illg ic reveal tile reasolls throllgll asystclllatic optillliz:lli…