尿中3-环戊醚雌二醇及其代谢产物的气液色谱分析

3-环戊醚雌二醇(3-cyclopentyl etherof estradiol,CE_2)是一个人工合成的雌激素类药物,本文采用气液色谱(GLC)测定了大鼠腹腔注射CE_2后尿中原药及其代谢产物的含量。 标准品混合物系由雌酚酮-3-醋酸酯、雌二醇-3,17-二醋酸酯、雌三醇-3,16,17-三     

新型衍生化试剂雌激素衍生物的大气压化学电离质谱增敏研究

合成了用于酚羟基化合物衍生化试剂10-乙基吖啶酮-2-磺酰氯(EASC),EASC与雌二醇和雌三醇, 在pH=10.5 的NaHCO3缓冲溶液中、60 ℃下反应3 min可获得稳定的衍生产物. EASC与丹磺酰氯(Dansyl-Cl)相比:最大摩尔吸光系数之比UVEASC/UVDansyl-Cl = 6.67;荧光量子效率之比Φf(EASC)/Φf(Dansyl-Cl)=43,对雌二醇和雌三醇标记后的质谱离子流强度比为:ICEASC/ICDansyl-Cl = 4.98(雌二醇) 和 ICEASC/ICDansyl-Cl = 4.51(雌三醇).在LC-MS-APCI (MRM)模式下,能够高灵敏地实现雌二醇和雌三醇的快速质谱测定.建立的方法具有良好的重现性,回归系数大于0.9995;检出限分别为4.3 ng/L(雌二醇)和14 ng/L(雌三醇).对实际样品中藏羚羊粪便、根田鼠尿样和狼血清中痕量游离的雌二醇和雌三醇进行了测定,结果满意.     

UPLC-MS/MS法分析婴幼儿配方乳粉中的12种雌性激素

建立了乳粉中12种雌性激素(孕酮、醋酸美伦孕酮、醋酸甲地孕酮、醋酸氯地孕酮、炔雌醇、雌三醇、17α-雌二醇、17β-雌二醇、雌酮、已烷雌酚、已烯雌酚、已二烯雌酚)的超高效液相色谱-串联质谱(UPLC-MS/MS)检测技术。样品用温水溶解、酶解后,经乙腈提取,HLB柱净化,使用ACQUITY UPLC BEH C18柱(2.1 mm×100 mm,1.7μm)分离,分别在电喷雾正、负离子模式下以多反应监测(MRM)方式检测孕激素和雌激素。结果表明,12种雌性激素的基质校准曲线在一定范围内线性关系良好,相关系数均大于0.99。3个浓度水平的平均回收率为80.2%~108.7%,相对标准偏差不高于7.9%。方法适用于婴幼儿配方乳粉中12种雌性激素的测定。     

超高效液相色谱-四极杆飞行时间串联质谱法同时分析奶粉中9种雌激素

建立了奶粉中9种雌激素(雌三醇、β-雌二醇、α-雌二醇、马烯雌甾酮、17α-乙炔雌二醇、雌酮、己烯雌酚、己二烯雌酚、己烷雌酚)的超高效液相色谱-四极杆飞行时间串联质谱(UPLC-Q-TOF-MS)分析方法.样品用水溶解,乙腈超声提取雌激素,正己烷除脂,NH2柱净化,经Waters ACQUITY UPLC HSS T3...     

高效液相色谱串联质谱法同时测定水产品中24种性激素

建立了同时测定24种性激素的高效液相色谱串联质谱法,包括:睾酮、甲基睾酮、诺龙、苯丙酸诺龙、群勃龙、康力龙、勃地酮、雄烯二酮、美雄酮、炔诺酮、乙酸甲孕酮、乙酸甲羟孕酮、乙酸氯地孕酮、17α羟基孕酮、21α羟基孕酮、甲羟孕酮、左炔诺孕酮、雌酮、雌二醇、雌三醇、炔雌醇、己烷雌酚、己烯雌酚、双烯雌酚。乙酸乙酯提取2次,硅胶柱净化。采用甲醇、水作为流动相,经过CAPCELLPAK C18色谱柱分离后,采用APCI离子源,外标法定量。方法定量限为0.5～2μg/kg,加标回收率为80%～102%,相对标准偏差为6%～10%。方法实现了3类性激素的同时定量及确证分析。     

气相色谱-质谱法同时测定饲料中6种雌激素类药物

建立了固相萃取/气相色谱-质谱法(GC-MS)同时测定饲料中己烷雌酚、己烯雌酚、双烯雌酚、雌酮、17β-雌二醇、雌三醇的检测方法。饲料样品经乙醚提取后,HLB固相萃取柱净化、衍生化后用气相色谱-质谱仪进行检测,外标法定量。结果表明,己烷雌酚在2.5~250 ng/m L,其它5种雌激素类药物在5~500ng/m L范围内具有良好的线性关系,相关系数不小于0.99,检出限为3~8μg/kg,样品的平均加标回收率为75.9%~96.3%。该方法检出限低,能够准确进行定性和定量测定,可同时测定饲料中的6种雌激素类药物。     

高效液相色谱-串联质谱法检测生物样品中6种雌激素

建立了雌酮、雌二醇、雌三醇、己烯雌酚、己烷雌酚和炔雌醇6种雌激素在生物体中的HPLC-MS/MS分析方法.采用加速溶剂萃取、固相萃取技术进行提取、富集及净化,有效降低了基质的干扰.以甲醇-0.1％氨水溶液为流动相,以C18色谱柱进行分离,质谱采用电喷雾负离子扫描模式,6种雌激素的回收率为88％～104％,相对标准偏差在1.3％～8.3％之间.雌酮、雌二醇、雌三醇在生物体中的方法检出限0.35ng/g;己烯雌酚、己烷雌酚、17α-乙炔基雌二醇在生物体中的方法检出限为0.13ng/g.方法适用于生物体内雌激素的分析和检测.     

雌激素药物中间体6-酮雌二醇的合成

以雌酚酮为起始原料,经硼氢化钠还原制得17β-雌二醇,再经乙酸酐酰化保护羟基和三氧化铬氧化得到3,17-乙酰基-6-酮-17β-雌二醇,最后经氢氧化钾水溶液水解合成了雌激素药物中间体6-酮雌二醇,总收率38.0%,其结构经1H NMR确证.     

液相色谱-串联质谱法快速测定饮用水中6种雌激素

建立了液相色谱-质谱法测定饮用水中17-β-雌二醇、17-α-雌二醇、17-α-乙炔雌二醇、己烷雌酚(HEX)、己烯雌酚(DES)和双烯雌酚(DE)6种雌激素的分析方法.样品经乙腈萃取,Oasis HLB柱富集净化后,采用液相色谱-质谱法测定.方法在5～100 μg/L范围内呈良好线性,相关系数为0.994～1.000...     

2-甲酰基雌甾化合物的合成及^1^3C核磁共振谱和质谱的研究

雌酚酮、雌二醇及炔雌醇与Grignard试剂交换后在HMPA存在下与聚甲醛反应, 实现了雌甾化合物的区域选择性甲酰化, 合成了一系列2-甲酰基雌甾化合物. 测定了它们的^1^3C NMR和MS, 讨论了分子中互为邻位的酰基和羟基对甲酰基碳、A环dmdo及其它碳的δc的影响; 讨论了主要碎片离子的生成途径及有关裂解规律.     

Characterization of end groups in nylon 6 by MALDI-TOF mass spectrometry

Four samples of Ny6, each terminated by different end groups, i.e., diamino terminated, monoamino terminated (monocapped), dicarboxyl terminated, and amino-carboxyl terminated, were synthesized and analyzed by MALDI-TOF Mass Spectrometry, in order to accurately characterize their structure by direct identification of mass resolved chains. A self-calibrating method for the MALDI-TOF mass spectra of polymeric samples was used in order to distinguish the end groups existing in the four samples of Ny6. The MALDI-TOF spectra showed the presence of protonated, sodiated, and potassiated ions that were assigned to Ny6 chains containing the expecteted end groups. Furthermore, the MALDI-TOF spectra made possible the simultaneous detection of the cyclic oligomers of Ny6 present in these samples, thus achieving the full structural characterization of the molecular species present in these polyamides. © 1996 John Wiley & Sons, Inc.     

Matching fluorescence spectra of oil spills with spectra from suspect sources

Fluorescence spectroscopy is ideally suited to the analysis of oil spills as it allows chemical information of polycyclic aromatic hydrocarbons to be acquired quickly, sensitively and selectively. Unlike infrared spectra which have detailed peak information, many fluorescence spectra have only a few broad peaks. Nine different samples of crude and diesel oils were used for testing point-to-point matching across the spectral range. Five of them were discriminated by point-to-point matching algorithms and the other four very similar samples were not. Principal components analysis (PCA) did successfully discriminate among all similar samples. PCA could also distinguish the extent of weathering of different samples, an important factor in matching environmental spills.     

Field Desorption Mass Spectrometry of Standard Organophosphorus Pesticides and Their Identification in Waste Water

The characteristic behaviour of four groups of commonly used organophosphorus pesticides such as phosphates, phosphorothionates, phosphorothiolates and phosphorodithioates has been investigated by field desorption mass spectrometry. Their spectra show molecular ions of high abundance and characteristic fragmentation patterns. The phosphates and phosphorothionates usually show the α-cleavage with respect to the P-atom with and without proton transfer. In contrast, the phosphorothiolates and phosphorodithioates usually show the β-cleavage from the P-atom. The fragments with the charge retention on the phosphorus moiety were also observed in the field desorption mass spectra, although their abundances were often relatively low.

The analyses of standard mixtures as well as some waste water samples indicate that field desorption mass spectrometry is suitable for the identification of organophosphorus pesticides at nanogram level in mixtures and environmental samples without preliminary separation and purification.     

拉曼光谱结合背景扣除化学计量学方法用于汽油中MTBE含量的快速测定研究

应用便携式拉曼光谱仪测量了汽油样本的拉曼光谱,以自适应迭代惩罚最小二乘方法(airPLS)对光谱进行了背景扣除和平滑处理,并选取特征峰区间利用偏最小二乘方法(PLS)建立了预测甲基叔丁基醚(MT-BE)的校正模型。以训练集相关系数和拟合误差及测试集相关系数和预测误差作为判定依据,确定了最佳建模条件。最终训练集相关系数为0.996 0,拟合误差为0.316 1,测试集相关系数为0.996 6,预测误差为0.490 1。结果表明采用便携式拉曼光谱结合化学计量学方法处理,可以满足对汽油中MTBE含量快速检测的要求。     

Analysis of lipoproteins using 2D diffusion-edited NMR spectroscopy and multi-way chemometrics

This study represents the first application of multi-way calibration by N-PLS and multi-way curve resolution by PARAFAC to 2D diffusion-edited ¹H NMR spectra. The aim of the analysis was to evaluate the potential for quantification of lipoprotein main- and subfractions in human plasma samples. Multi-way N-PLS calibrations relating the methyl and methylene peaks of lipoprotein lipids to concentrations of the four main lipoprotein fractions as well as 11 subfractions were developed with high correlations (R = 0.75-0.98). Furthermore, a PARAFAC model with four chemically meaningful components was calculated from the 2D diffusion-edited spectra of the methylene peak of lipids. Although the four extracted PARAFAC components represent molecules of sizes that correspond to the four main fractions of lipoproteins, the corresponding concentrations of the four PARAFAC components proved not to be correlated to the reference concentrations of these four fractions in the plasma samples as determined by ultracentrifugation. These results indicate that NMR provides complementary information on the classification of lipoprotein fractions compared to ultracentrifugation.     

Classification of biodiesel using NIR spectrometry and multivariate techniques

This article describes the classification of biodiesel samples using NIR spectroscopy and chemometric techniques. A total of 108 spectra of biodiesel samples were taken (being three samples each of four types of oil, cottonseed, sunflower, soybean and canola), from nine manufacturers. The measurements for each of the three samples were in the spectral region between 12,500 and 4000 cm⁻¹. The data were preprocessed by selecting a spectral range of 5000-4500 cm⁻¹, and then a Savitzky-Golay second-order polynomial was used with 21 data points to obtain second derivative spectra. Characterization of the biodiesel was done using chemometric models based on hierarchical cluster analysis (HCA), principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA) elaborated for each group of biodiesel samples (cotton, sunflower, soybean and canola). For the HCA and PCA, the formation of clusters for each group of biodiesel was observed, and SIMCA models were built using 18 spectral measurements for each type of biodiesel (training set), and nine spectral measurements to construct a classification set (except for the canola oil which used eight spectra). The SIMCA classifications obtained 100% accurate identifications. Using this strategy, it was feasible to classify biodiesel quickly and nondestructively without the need for various analytical determinations.     

Characterization of acrylic dental polymers

The chemical structure and the molecular parameters of four dental acrylic polymer materials (samples P-1 to P-4) and two polyacrylic acids of different molecular weight (relative molecular mass) used as model compounds (samples Paa-1 and Paa-2) were studied and correlated with polymer structure and molecular weight. All polymer samples show low molecular weights, MW, and broad poly-dispersity as obtained by GPC. Samples P-3 and P-4 show the lower MW and bi-modal distribution, one peak corresponding to the polymer and the other to a low molecular weight compound at a lower concentration. The other polymer samples show unimodal distribution. Initially, all samples were soluble in water and dioxane above 99.8%. However, after lyophilization at −50 °C they showed different degrees of solubility because of partial gelation. The FTIR and, ¹H and ¹³C-NMR spectra of Paa-1, Paa-2 in D₂O show the pattern characteristic of poly(acrylic acid). The polymers of P-1 and P-2 are mainly poly(acrylic acid). The P-3 spectra show the peak pattern for an (acrylic acid/methyl acrylate) copolymer of about 2:1 composition as calculated from the NMR spectra. The P-4 is an oligomer derived from 2-hydroxyethyl methacrylate. Solid ¹³C-NMR spectra confirm the above structures and evidence anhydride formation after lyophilization. The MW and the linear expansion coefficient, α, were derived from intrinsic viscosity in theta and perturbed conditions. From this, the steric hindrance parameter, A, the molecular stiffness, σ, and the second virial coefficient, A₂, were calculated using different thermodynamic models. The Flory-Fox-Shafgagen and the Stockmayer-Fixman models fit better the experimental data and can be used to describe the molecular parameters of the acrylic polymers. Light scattering was used to compare results.     

Determination of biogenic amines in apples and wine with 8-phenyl-(4-oxy-acetic acid N-hydroxysuccinimide ester)-4, 4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene by high performance liquid chromatography

A solvent free, fast and environmentally friendly photoacoustic-infrared-based methodology (PAS-FTIR) was developed for the determination of Mancozeb in agrochemicals. This methodology was based on the direct measurement of the transmittance spectra of solid samples and a multivariate calibration model to determine the active ingredient concentration. The proposed partial least squares (PLS) model was made using nine standards prepared by mixing different amounts of kaolin and Mancozeb, with concentrations between 5.43 and 88.10% (w/w).A hierarchical cluster analysis was made in order to classify the samples in terms of similarity in the PAS-FTIR spectra. From their spectra different commercially available fungicide samples were classified in four groups, attending to the presence of other active ingredients co-formulated with Mancozeb. Different PLS models were applied for the analysis of each group of samples.So, for samples containing copper oxychloride (group 1), the information in the spectral range from 1543 to 1474 and 1390 to 1269 cm⁻¹ was employed. For samples co-formulated with Fosetyl-Al (group 2) the range between 3334 and 3211 cm⁻¹, corrected with a single point baseline located at 3055 cm⁻¹, was used. For samples containing Metalaxyl (group 3) it was used the information in the spectral range from 1543 to 1474 cm⁻¹ was used to determine Mancozeb. Finally, the range between 1456 and 1306 cm⁻¹ was used for Mancozeb determination in samples containing Cymoxanil (group 4).The PLS factors used for Mancozeb determination depends on the PLS model employed. 3, 2, 2 and 3 factors were used for Mancozeb determination in commercially available pesticides for groups 1, 2, 3 and 4, respectively. The mean accuracy errors found were 3.1, 2.1, 2.5 and 3.0% for groups 1, 2, 3 and 4, respectively. The developed PAS-FTIR methodology does not consume any solvent, as no sample preparation is necessary it improves the laboratory efficiency without sacrifice the accuracy and avoids the contact of the operator with toxic substances.     

A Chemical Recognition Element for Lithium Ions Based on Optical Electronic Absorption

Xerogel samples with entrapped series of four optical absorption chemosensors were prepared by sol-gel process. These materials are proposed as chemical recognition elements of an optical chemical sensor. The roles of the chemosensors play proton-dissociable chromogenic azocrown ethers bearing phenol and two azo groups as parts of macrocycles. Occurrence of the alkali ion—receptor interaction is signalled by the chemosensors changing their electronic absorption spectra. By this way chemosensor 4O-CH₃ is able to distinguish Li⁺ ions from other alkali metal ions present in aqueous solution, if the chemosensor is entrapped in Glymo-silica (1:1) xerogel matrix. The proposed recognition element for Li⁺ has been exposed to the cycles chemisorption—desorption many times. Besides DRIFT spectra of the used xerogel matrices were analyzed.     

Synthesis and characterization of hydroxyapatite obtained from different organic precursors by sol–gel method

The synthesis of four types of hydroxyapatite synthesized from calcium chloride and four different organic phosphites is presented. The method of synthesis chosen is the sol–gel route, which has a number of advantages compared to other methods, like the intimate contact between reactants and the milder synthesis conditions. The samples were thermally treated, the TG/DTG/DTA curves being obtained at four heating rates, namely: 7, 10, 12 and 15 °C min⁻¹. The samples were characterized before and after the thermal treatment using FT-IR analysis. The FT-IR spectra certified that the formed compounds represent hydroxyapatite. Based on the information from the TG curves and IR spectra interpretation, a reaction mechanism was proposed.