反相流动注射化学发光法测定黄芩苷

在碱性介质中,K3Fe(CN)6氧化鲁米诺产生化学发光,黄芩苷对该体系化学发光具有强烈的抑制作用。利用该化学发光的抑制体系,结合反相流动注射技术,建立了测定黄酮类药物黄芩苷含量的新方法。在优化的条件下,黄芩苷浓度在1.0×10-8～1.0×10-7和3.0×10-7～4.0×10-6mol/L范围内与化学发光抑制强度ΔI呈良好的线性关系,检出限为1.0×10-9mol/L,对3.0×10-7mol/L的黄芩苷进行平行测定10次,得相对标准偏差(RSD)为1.7%。该方法可应用于银黄口服液中黄芩提取物(黄芩苷计)的含量测定。     

中空纤维协同液相微萃取在4种莨菪碱分析中的应用

利用协同液相微萃取方法初步探讨氢溴酸山莨菪碱、硫酸阿托品、氢溴酸东莨菪碱和丁溴酸东莨菪碱的优势构象;阐明有机溶剂对4种莨菪碱的萃取选择性和协同萃取作用机理;探讨中空纤维与莨菪碱形成电荷转移超分子对萃取效果的影响以及4种莨菪碱结构中N原子的亲电能力;结合高效液相色谱技术测定药物制剂中4种莨菪碱的含量。4种莨菪碱的线性范围均为0.05～5mg/L(r0.99),方法RSD小于7%,消旋山莨菪碱片和颠茄片中平均回收率分别为95.0%～119.0%和93.0%～95.0%,氢溴酸山莨菪碱和丁溴酸东莨菪碱检出限为0.03mg/L,硫酸阿托品和氢溴酸东莨菪碱检测出限为0.01mg/L。     

胶束增敏分光光度法水相测定乳制品中三聚氰胺

建立了一种基于胶束增敏缔合反应水相测定乳制品中三聚氰胺的分光光度法,研究了在阴离子表面活性剂十二烷基硫酸钠(SDS)形成的胶束体系中,茜素红(AR)阴离子与三聚氰胺阳离子反应产物的紫外-可见光谱特性。实验发现,加入三聚氰胺后,体系λmax由426nm红移到516nm,加入SDS对缔合物有显著的增稳、增敏效应。三聚氰胺质量浓度在1.9～25mg/L范围内符合比尔定律,缔合物的表观摩尔吸光系数为6.9×103L.mol-1.cm-1。本方法用于液态奶及奶粉中三聚氰胺的测定,回收率分别为94.5%～104.8%和95.5%～100.4%,相对标准偏差分别为1.6%～2.2%和1.7%～2.6%。考察了酸效应、胶束对体系的作用机理,发现三聚氰胺与AR缔合物之间主要是通过静电引力和疏水作用力相结合。     

Preparation of high density polyethylene/polyethylene-block-poly(ethylene glycol) copolymer blend porous membranes via thermally induced phase separation process and their properties

<正>High density polyethylene(HDPE)/polyethylene-block-poly(ethylene glycol)(PE-b-PEG) blend porous membranes were prepared via thermally induced phase separation(TIPS) process using diphenyl ether(DPE) as diluent.The phase diagrams of HDPE/PE-b-PEG/DPE systems were determined by optical microscopy and differential scanning calorimetry(DSC).By varying the content of PE-b-PEG,the effects of PE-b-PEG copolymer on morphology and crystalline structure of membranes were studied by scanning electron microscopy(SEM) and wide angle X-ray diffraction(WAXD). The chemical compositions of whole membranes and surface layers were characterized by elementary analysis,Fourier transform infrared spectroscopy-attenuated total reflection(FTIR-ATR) and X-ray photoelectron spectroscopy(XPS).Water contact angle,static protein adsorption and water flux experiments were used to evaluate the hydrophilicity,antifouling and water permeation properties of the membranes.It was found that the addition of PE-b-PEG increased the pore size of the obtained blend membranes.In the investigated range of PE-b-PEG content,the PEG blocks could not aggregate into obviously separated domains in membrane matrix.More importantly,PE-b-PEG could not only be retained stably in the membrane matrix during membrane formation,but also enrich at the membrane surface layer.Such stability and surface enrichment of PE-b-PEG endowed the blend membranes with improved hydrophilicity,protein absorption resistance and water permeation properties,which would be substantially beneficial to HDPE membranes for water treatment application.     

高效液相色谱法测定全血中直链烷基苯磺酸钠

提出了高效液相色谱法测定全血中直链烷基苯磺酸钠同系物的含量。全血样品用酸性提取溶液稀释,过Bakerbond SPE C18固相萃取小柱,经甲醇-乙酸-水(49+2+49)混合溶液淋洗后用甲醇-氨水(98+2)混合溶液洗脱。经纯化后的洗脱液在Wakopak WS AS-Aqua(250 mm×4.6 mm,5μm)柱上进行分离,流动相为乙腈与水(60+40)混合溶液,检测波长为228 nm。5种n-ABS同系物的C10~C14的质量分数在10.0~100.0 ng.g-1范围内与其峰面积呈线性关系,全血中各同系物回收率为78%~107%;日内相对标准偏差(n=5)≤10%,日间相对标准偏差(n=5)≤13%。     

固相微萃取-气相色谱法测定食品包装材料中残留有机溶剂

提出了一种以固相微萃取与气相色谱-氢火焰联用技术为基础的测定食品包装材料中15种常用有机溶剂(苯类、醇类、酮类、酯类等)的方法。选择聚二甲亚砜作为固相微萃取的萃取相,采用DB-624毛细管色谱柱进行分离。在优化的试验条件下,15种有机残留溶剂在20min内能很好地分离,15种溶剂的测定下限(10S/N)为0.08～0.69μg.dm-2。加标回收率为60.0%～115.0%,相对标准偏差(n=5)为2.17%～8.34%。     

UPLC-MS/MS对卷烟烟气中4种烟草特有亚硝胺的快速测定

建立了卷烟主流烟气中烟草特有亚硝胺的超高效液相色谱-电喷雾串联质谱(UPLC-MS/MS)测定方法。在标准吸烟条件下,采用剑桥滤片收集卷烟烟气粒相物,用醋酸铵缓冲液提取粒相物,经固相萃取净化后,以电喷雾正离子多反应监测方式,实现了烟气中N-亚硝基降烟碱、4-甲基亚硝基吡啶基丁酮、N-亚硝基新烟草碱和N-亚硝基假木贼碱的基线分离和快速测定。4种烟草特有亚硝胺在0~400μg/L范围内具有良好线性,相关系数大于0.998,定量下限为0.08~0.15μg/L,加标回收率为72%~104%,相对标准偏差为3.8%~9.7%。该方法灵敏、快速、准确,适用于卷烟烟气中烟草特有亚硝胺的测定。     

核-壳型苏丹红Ⅰ印迹聚合物微球制备及应用研究

以苏丹红Ⅰ为模板分子,苯基-三甲氧基硅烷(PTMOS)为功能单体,乙二醇二甲基丙烯酸酯(EGD-MA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用表面分子印迹技术,在自制的SiO2微球表面成功合成了对苏丹红Ⅰ具有良好选择识别性能的核-壳型印迹聚合物。采用红外光谱和扫描电子显微镜对分子印迹微球进行表征,结果表明该印迹聚合材料壳层厚度约为150 nm;采用静态吸附实验研究印迹材料对模板聚合物的吸附性能和选择特性,结果表明以PTMOS为功能单体的印迹聚合物对苏丹红Ⅰ具有优异的选择吸附性,其分离选择因子为2.62。在吸附过程中,模板分子苏丹红Ⅰ与印迹聚合物形成2种结合位点,2种结合位点的解离常数分别为2.30、10.78 mmol/L,最大表观结合量分别为27.40、128.53μmol/g。将该印迹聚合物作为固相萃取材料,对样品进行固相萃取,结合液相色谱技术成功用于辣椒油中苏丹红Ⅰ的测定。     

Structure and performance of polyamide-6 membranes prepared by thermally induced phase separation

<正>The asymmetric polyamide-6(PA6) membranes were prepared by thermally induced phase separation.From the scanning electron microscopy(SEM) images,it is observed that with the increase of silicon dioxide(SiO_2) content the structure of obtained membranes gradually varied from cellular structure to large ball-shaped cluster aggregates. Subsequently,with the addition of SiO_2,pure water flux increased first and then decreased,while rejection showed the opposite trend.Besides,raising the coagulation bath temperature was favorable to increase pure water flux.Consequently, different membrane morphologies and performance were obtained by changing SiO_2 content and coagulation bath temperature.