MIL-101(Cr)填充针头式过滤器固相微萃取/高效液相色谱法检测水中雌激素

建立了多孔金属有机骨架MIL－101（Cr）填充针头式尼龙过滤器固相微萃取结合高效液相色谱－荧光检测器对水中雌二醇（E2）、雌三醇（E3）、雌酮（E1）3种雌激素进行快速检测的方法。MIL－101（Cr）与尼龙滤膜对雌激素表现出协同吸附效果。通过对萃取材料以及新型萃取装置制备过程、吸附、洗脱过程进行优化,可对10 mL水样中3种雌激素实现4 min吸附、1 min洗脱的快速前处理。结果显示,E2和E3在0.2～500 μg/L、E1在5～500 μg/L质量浓度范围内线性良好,相关系数（r2）为0.998 2～0.999 3,检出限分别为0.05、0.06、1.50 μg/L,日内和日间相对标准偏差（RSD）分别为0.20%～3.2%（n = 6）和 5.9%～6.1%（n = 3）。水样中3种分析物的加标回收率为84.1%～108%,RSD均不大于5.5%。该方法简单方便、灵敏度高,能够用于水样中3种雌激素的快速筛查和准确定量。     

固相萃取-衍生化气相色谱/质谱法测定制药厂污水中的环境雌激素

采用固相萃取-衍生化气相色谱/质谱法(GC/MS)测定某制药厂污水中的雌酮(E1)、雌二醇(E2)、雌三醇(E3)和乙炔基雌二醇(EE2)4种雌激素化合物。样品经固相萃取柱萃取富集及双(三甲基硅烷基)三氟乙酰胺(1%三甲基氯硅烷)（BSTFA(1%TMCS)）衍生化后进行GC/MS分析。该法对4种目标物的检出限为1.8～4.7 ng/L,相对标准偏差为2.3%～9.1%(n=8)。目标化合物的加标回收率为（94.0±2.9）%～（101±3.8）%,说明该方法能较好地应用于污水中雌激素化合物的定量检测。通过对某制药厂污水中的雌激素进行定量分析,发现污水中乙炔基雌二醇和雌酮质量浓度分别达396.6 和39.9 ng/L;经过传统的厌氧兼氧好氧生物处理后,污水中的环境雌激素的去除率仅为35%～40%,说明传统的污水处理工艺对去除污水中雌激素效果并不明显,需要改进。     

固相萃取-衍生化-气相色谱-质谱法测定水中类固醇类雌激素

采用固相萃取-衍生化-气相色谱-质谱法同时测定水中4种类固醇类雌激素雌酮(E1)、17β-雌二醇(E2)、17α-乙炔基雌二醇(EE2)、雌三醇(E3)。样品经Oasis HLB固相萃取柱,以丙酮为溶剂进行洗脱后,采用吡啶、N-甲基-N-三甲基硅基三氟乙酰胺于40℃衍生化20min后,采用气相色谱-质谱仪分析。E1、E2、EE2和E3的线性范围分别为5.00~500μg·L-1和10.0~500μg·L-1,4种类固醇类雌激素的检出限(3S/N)在1.5~3.0μg·L-1之间,测定下限(10S/N)在5.0~10μg·L-1之间;方法用于实际水样的分析,加标回收率在86.8%~93.8%之间,测定值的相对标准偏差(n=7)在7.1%~11%之间。     

气相色谱-质谱联用法同时测定牛奶中的6种天然雌激素

天然雌激素是一类内源性激素,但其外源性摄入可能对人体健康造成危害。牛奶是人体外源性天然雌激素的重要来源之一,对牛奶中天然雌激素的准确分析是评价人体外源摄入的重要前提。该研究建立了一种气相色谱-质谱联用(GC-MS)同时测定牛奶中雌酮(E1)、17α-雌二醇(17α-E2)、17β-雌二醇(E2)、雌三醇(E3)、16α-羟基雌酮(16αOHE1)和16keto雌二醇(16ketoE2)6种天然雌激素的分析方法。选择不同类型牛奶样品,依次通过液液萃取、固相萃取富集净化,再利用BSTFA+1%TMCS进行衍生化,乙酸乙酯定容后采用GC-MS进行测定。结果显示,6种雌激素在5～100μg/L范围内线性关系良好,相关系数(r²)大于0.995;检出限(LOD)和定量下限(LOQ)分别为0.17～0.51μg/L和0.56～1.68μg/L;平均加标回收率为83.1%～119%,相对标准偏差(RSD)为2.1%～15%,该方法具有较好的准确性及稳定性。利用所建方法对实际牛奶样品中的天然雌激素进行检测,除常见的天然雌激素E1、E2、17α-E2之外,样品中还检测出16αOHE...     

聚(甲基丙烯酸-乙二醇甲基丙烯酸酯)微固相萃取-超高效液相色谱-串联质谱法测定水中雌激素

制备了聚(甲基丙烯酸-乙二醇甲基丙烯酸酯)有机聚合材料用于微固相萃取吸附剂,结合超高效液相色谱-串联三重四级杆质谱,建立了膜保护微固相萃取快速测定水体中E1、E2、E3、EE2和BPA 5种典型雌激素的方法。详细研究了萃取条件和解析条件对萃取效果的影响。在优化实验条件下,E3的检出限为0.2μg/L,线性范围为1～500μg/L,其余4种目标物检出限为0.02μg/L,线性范围为0.1～500μg/L。相对标准偏差均小于7.4%。方法用于实际污水处理厂污水中痕量雌激素的测定,样品加标回收率大于83%。     

衍生化高效液相色谱法分析烯唑醇、烯效唑光学异构体

报道烯唑醇和烯效唑光学异构体的色谱分析方法,样品与R（－）－戊菊酸反应制备成非对映衍生物,然后在普通高效液相色谱柱上实现了R（－）和S（＋）光学异构体的分离与测定,方法的精确度为相对标准偏差2．0－2．5％（n=8)。\异构体衍生物的化学结构用气相色谱／质谱和红外光谱法鉴定。     

超高效液相色谱-串联质谱法测定环境水体/污泥中5种痕量雌激素

对固相萃取条件、加速溶剂萃取条件进行了优化,采用内标法结合超高效液相色谱-串联三重四极杆质谱仪进行测定,建立了环境水样、污泥中5种典型雌激素的测定方法。在最佳条件下,水样中5种雌激素的检出限为0.8 ng/L(除E3的检出限为1 ng/L),线性范围为3～1000 ng/L,相关系数在0.9566～0.9999之间;污泥样品中5种雌激素的检出限为0.5 ng/g(除E3的检出限为0.8 ng/g),线性范围为2.5～500 ng/g,相关系数在0.9224～0.9999之间。方法用于实际环境水样、泥样中痕量雌激素的测定。     

GC法测定青岛某水体中雌激素含量

介绍了测定环境水中几种雌激素,如:雌酮(E1)、雌二醇(E2)、雌三醇(E3)和雌炔醇(EE2)的测定方法.用C-18小柱对水体中的雌激素进行富集.研究了用TFA、MSTFA对雌激素的衍生化条件.GC-FID及GC-MS法测定衍生化雌激素的工作曲线,相关系数在0.98~0.99之间.测得500 mL实际水样中的加标回收率为86%~120%.5 000 mL环境水样的方法检测限为1~3 ng/L.用GC-MS法测定了海水和河水中的雌激素含量.     

液相色谱串联质谱法测定牛奶中的内源性雌激素

建立了液相色谱-串联质谱法测定牛奶中4种内源雌激素的方法,可用于牛奶中17-α-雌二醇、17-β-雌二醇、雌三醇和雌酮等4种内源雌激素的同时测定。牛奶样品中添加内标化合物后,经过酶解、提取、净化、衍生等步骤获得上机试液,用LC-MS/MS测定,采用多反应监测正离子模式扫描。实验表明,4种化合物溶液质量浓度在0.0625~5.0μg/L之间有较好的线性关系,相关系数(R2)0.995,方法检出限在0.28~0.64 ng/kg之间。17-α-雌二醇回收率较低,只有60%左右,其它化合物的回收率均在72%~115%、相对标准偏差10%。在对57个样品的实际检测中,牛初乳E1,αE2,βE2,E3平均含量为3220,727,889,167 ng/kg;常乳中E1,αE2,βE2,E3含量为19.3~520 ng/kg,2.3~90.2 ng/kg,3.3~46.0 ng/kg,未检出~19.2 ng/kg。     

α,β-炔醛异构化高立体选择性合成(2E,4E)-十四碳共轭双烯醛

（2E，4E）－共轭双烯是许多天然产物的结构组分[1-5]，由于几何异构体的分离及提纯较困难，因此合成高几何纯度的（2E，4E）共轭双烯衍生物是一个值得探讨的课题．Trost等[1]曾报道了利用α,β-炔酮及炔胺的异构化反应合成（2E，4E）－共轭双烯衍生物的方法．     

Voltammetric behavior and determination of estrogens at Nafion-modified glassy carbon electrode in the presence of cetyltrimethylammonium bromide

A method is described for the determination of estrogens (estradiol, estrone and estriol) by stripping voltammetry. These estrogens yield one well-defined oxidation peak at the Nafion-modified glassy carbon electrode in the presence of cetyltrimethylammonium bromide (CTAB). The peak current is proportional to the concentration of estradiol in the range from 2.5×10⁻⁸ to 1.5×10⁻⁶ mol/l, and the detection limit is 1×10⁻⁹ mol/l after accumulation of 6 min. The total amounts of estrogens in the blood serums were determined using the voltammetric method, and the average recovery was 106.04%. The mechanism of the oxidation of estradiol was investigated by electrochemical techniques and UV spectra.     

Adsorption stripping voltammetry of phenol at Nafion-modified glassy carbon electrode in the presence of surfactants

In this paper, a new voltammetric method for the determination of phenol is described. In pH 8.00 phosphate buffer and in the presence of long-chain cationic surfactant—cetyltrimethylammonium bromide—phenol has a very sensitive oxidation peak at 0.47 V (vs. SCE) on the Nafion-modified glassy carbon electrode (GCE). The experimental parameters, such as supporting electrolyte and pH values, amounts of Nafion, varieties and concentration of surfactants, accumulation potential and time, as well as scan rate were optimized. The peak current is linear with the concentration of phenol in the range from 8×10⁻⁹ to 1×10⁻⁵ M, and the detection limit is 1×10⁻⁹ M after being accumulated at −0.50 V (vs. SCE) for 3 min. Trace levels of phenol in water samples were determined by using this voltammetric method, the average recovery was calculated to be 99.56%.     

Voltammetric determination of antibacterial drug gemifloxacin in solubilized systems at multi-walled carbon nanotubes modified glassy carbon electrode

A sensitive electroanalytical method for determination of gemifloxacin in pharmaceutical formulation has been investigated on the basis of the enhanced electrochemical response at multi-walled carbon nanotubes modified glassy carbon electrode in the presence of CTAB. Solubilized system of different surfactants including SDS, Tween-20 and CTAB were taken for the study of electrochemical behaviour of gemifloxacin at modified electrode. The reduction peak current increases in the presence of CTAB while other surfactants show opposite effect. The modified electrode exhibits catalytic activity, high sensitivity, stability and is applicable over wide range of concentration for the determination of gemifloxacin. The mechanism of electrochemical reduction of gemifloxacin has been proposed on the basis of CV, SWV, DPV and coulometeric techniques. The proposed squarewave voltammetric method shows linearity over the concentration range 2.47-15.5 μg/mL. The achieved limits of detection (LOD) and quantification (LOQ) are 0.90 ng/mL and 3.0 ng/mL respectively.     

Nafion修饰玻碳电极吸附伏安法直接测定邻氨基苯酚

在 p H=2 .0的 0 .1 mol/ L H3 PO4 缓冲溶液中 ,开路搅拌富集 2 min后 ,从 0 .0 0～ +1 .0 0 V阳极扫描 ,OAP在 Nafion修饰玻碳电极上出现一灵敏的氧化峰 ,峰电位位于 0 .44 V。该峰电流与 OAP在 1× 1 0 - 7～ 2 .5× 1 0 - 5mol/ L的浓度范围内有良好的线性关系 ,检出限为 1× 1 0 - 8mol/ L。对支持电解质的种类及 p H值、Nafion的用量、富集电位及时间、以及扫描速度等进行了优化 ,提出了一种直接测定邻氨基苯酚的电化学方法。将此方法用于水样中邻氨基苯酚的测定 ,取得了满意的结果     

Determination of trace amounts of estriol and estradiol by adsorptive cathodic stripping voltammetry.

Estriol and estradiol are electroinactive in the potential range from -200 to -1000 mV versus a silver-silver chloride electrode at a mercury electrode. The conversion of these estrogens into electroactive nitro derivatives of estrogens, which are used for voltammetric determination, was studied. Such nitro derivatives give a well defined cathodic stripping wave at -600 mV in pH 10.5 borate buffer. Estriol and estradiol are determined in the ranges 1 x 10(-9)-1.5 x 10(-6) and 5 x 10(-9)-2 x 10(-6) mol dm-3, respectively, by differential-pulse adsorptive stripping voltammetry at a hanging mercury drop electrode. Some steroids, such as estrone, interfere because the three estrogens have almost the same molecular structure and have similar nitro derivatives, but progesterone does not interfere and is reduced at significantly more negative potentials than the nitrated estrogens. It can be determined simultaneously with estriol or estradiol. A method was developed for the assay of estriol in pharmaceutical preparations.     

阿昔洛韦在硼掺杂金刚石电极上的电化学行为及其与DNA相互作用的研究

利用硼掺杂金刚石(BDD)电极通过循环伏安法和微分脉冲伏安法研究了阿昔洛韦在0.10 mol/L磷酸盐缓冲溶液(pH 7.4)中的电化学行为及其与DNA的相互作用.与玻碳电极相比,阿昔洛韦在BDD电极上的循环伏安曲线在1.17 V处的氧化峰电流更大,背景电流较低.根据峰电位随溶液pH值和扫描速率的变化趋势考察了阿昔洛韦...     

Enhanced reduction and determination of trace thyroxine at carbon paste electrode in the presence of trace cetyltrimethylammonium bromide.

The electrochemical response of thyroxine (T4) at a carbon paste electrode (CPE) in the presence of cetyltrimethylammonium bromide (CTAB) was investigated. It gave a well-defined oxidation peak at 0.80 V and a sensitive reduction peak at 0.40 V. Compared with the indiscernible signal in the absence of CTAB, the reduction current of T4 at CPE was greatly enhanced in the presence of CTAB, due to the interactions between T4, CTAB and the hydrophobic electrode surface. The electrode process of T4 was explored by cyclic voltammetry and chronocoulometry. The effect of surfactants on the reduction reaction proved that bromide ions (Br(-)) in CTAB might form special ion complexes with T4 via a special interaction with the iodine atoms on T4, which would activate the reduction of T4. The sensitive and selective reduction of T4 in this system was applied to the determination of T4 in drugs; a detection limit of 6.5 x 10(-9) M was obtained (sigma= 3).     

多巴胺和抗坏血酸在十六烷基三甲基溴化铵/碳纳米管电极上的检测

研究了十六烷基三甲基溴化铵(CTMAB)/多壁碳纳米管修饰玻碳电极的制备以及多巴胺和抗坏血酸在该修饰电极上的电化学行为。在CTMAB和多壁碳纳米管的协同作用下,该修饰电极对多巴胺和抗坏血酸均具有显著的催化氧化作用,多巴胺和抗坏血酸的氧化峰电位分别为223mV和15mV,实现了在抗坏血酸共存时测定多巴胺。在pH7.0的磷酸盐缓冲溶液中,多巴胺和抗坏血酸的线性范围分别为2.0×10-6～2.0×10-3mol/L和4.0×10-5～1.0×10-2mol/L,检出限分别为6.0×10-7mol/L和1.0×10-5mol/L。     

在抗坏血酸存在下用L-赖氨酸修饰玻碳电极测定多巴胺

采用电化学氧化法制备了L-广赖氮酸单分子层修饰玻碳电极，研究了多巴胺（DA）和抗坏血酸（AA）在该电极上的电化学行为。结果表明，L-广赖氨酸单分子层修饰玻碳电极不仅能改善多巴胺和抗坏血酸的电化学行为，而且能将多巴胺和抗坏血酸二者在裸电极上的完全重叠的单氧化峰分开成为两个完全独立的氧化峰，循环伏安（CV）图上峰间距为507mV，差分脉冲伏安（DPV）图上峰间距为460mV，由此可实现在AA的共存下对样品中的DA进行选择性测定。     

Hydrophobic adsorption of surfactants on water-soluble carbon nanotubes: A simple approach to improve sensitivity and antifouling capacity of carbon nanotubes-based electrochemical sensors

Water-soluble multi-walled carbon nanotubes (MWNTs) were prepared by the strong adsorption of Congo red (CR) on MWNTs. The CR-functionalized MWNTs (MWNTs–CR) had a high solubility, a high purity and a special property of strong rebundling when dried, capable of forming uniform and compact MWNTs films with a 3D network structure of nanosizes on a glassy carbon electrode (GCE). Compared with GCE, the electrochemical response of estradiol at a MWNTs–CR modified glassy carbon electrode (MWNTs–CR/GCE) was greatly enhanced, which was further amplified by the addition of trace cetyltrimethylammonium bromide (CTAB) in solution, along with the accomplishment of antifouling capacity of the modified electrode. The weak hydrophobic adsorption of surfactants on the hydrophobic and smooth surface of MWNTs was found to be the key for simultaneously improving the sensitivity and antifouling capacity of carbon nanotube-based electrochemical sensors by surfactants.