铈对三角帆蚌钙代谢影响的研究

研究了不同浓度稀土Ce3+(0,0.5,1.0,2.5 mg·L-1)处理30,60 d时对2龄植片三角帆蚌钙代谢和珍珠质沉积的影响。结果表明:Ce3+对三角帆蚌珍珠质沉积量、外套膜和鳃组织中组织钙含量、钙调蛋白基因mRNA的表达量、腺苷三磷酸酶(ATPase)活性、碱性磷酸酶(ALP)活性的影响总体上均表现出明显的"低促高抑"的剂量效应和高浓度下"先促后抑"的时间效应。推测稀土Ce3+对钙调蛋白基因mRNA表达水平及关键酶活性的调节可能是其影响三角帆蚌钙代谢和珍珠质沉积的途径之一。     

气相色谱-质谱法测定三角帆蚌珍珠层粉中微量有机化学成分

用气相色谱-质谱法测定三角帆蚌珍珠层粉,用二氯甲烷作溶剂先后在pH2,pH7及pH12的条件下萃取样品溶液,合并所得有机相,在50℃蒸发至1mL供气相色谱-质谱法分析。经DB-5MS毛细管柱分离后,从总离子流色谱图上可辨认17个色谱峰,对其中的11种有机化合物作出了鉴别并对其峰面积用归一化法计算其相对含量。此11种化合物占了总量的70.73%,其中主要化合物为瓢儿菜酰胺、1-氯二十七烷、4,6-二叔丁基-间-甲苯酚、邻苯二甲酸丁基异丁基酯、2-[1-(4-氯苄基)-1,4-二氢吡啶-4-叶立德烯]2,3-二氢茚-1,3-二酮等。     

常见茶叶中14种元素含量分析及重金属风险评价

采集传统名茶地标产品样品各3种为实验样品,通过ICP-OES和ICP-MS对样品进行K、Ca、Mg、Mn、B、Cu、Fe、Ni、Zn、Cr、Co、Cd、As、Pb等14种元素的含量测定.利用单因素方差分析、主成分分析、污染评价等方法,对茶叶无机元素含量进行分析和污染评价,并对污染来源进行了研究.结果表明,不同产地茶叶样...     

基于ICP-MS分析的苜蓿矿质元素含量特征与评价

为了探明进口和国产苜蓿总体矿质差异,以国产和进口苜蓿为对象,采用石墨消解-电感耦合等离子体质谱(ICP-MS)法分析干草中磷、钾和锌等17种矿质元素的含量特征,并对矿质元素含量进行了相关性、主成分分析和评价。结果表明,苜蓿干草中矿质元素种类丰富而含量变异较大,平均含量最高的是K元素,其次是Ca>Mg>Na>P,Al元素含量显著高于其他11种微量元素。Cu、K、Mg、Al、K、Ca两两元素间存在极显著正相关(p<0.01);Ca、Cu、Mg、K、Zn、Co和Na是苜蓿干草的主要特征矿质元素,累积方差贡献率达74.90%。进口苜蓿中K、Ca、Mg、Cu含量显著高于国产苜蓿,而国产苜蓿中Na和Co含量显著高于进口苜蓿。针对国产苜蓿营养缺乏,应在选种和肥料管理中重视增施钾肥和其他微量元素,合理利用苜蓿草产品。     

基于ICP-MS分析的苜蓿矿质元素含量特征与评价

为了探明进口和国产苜蓿总体矿质差异,以国产和进口苜蓿为对象,采用石墨消解-电感耦合等离子体质谱(IC P-M S)法分析干草中磷、钾和锌等17种矿质元素的含量特征,并对矿质元素含量进行了相关性、主成分分析和评价.结果表明,苜蓿干草中矿质元素种类丰富而含量变异较大,平均含量最高的是K元素,其次是Ca>M g>Na>P,A...     

封闭压力酸溶-ICP-MS法分析地质样品中47个元素的评价

对封闭压力酸溶－ICP－MS法同时测定地质样品中47个元素的效果和适用范围进行了实测评价。并对溶样条件进行了优化。实验结果表明，HF－HNO3高温高压酸溶是一种有效的样品分解方法，在所测定的47个元素中，大部分元素如Li,Be,Ti,V,Mn,Co,Ni,Cu,Zn,As,Zr,Nb,Mo,Cd,In,Sn,Sb,Hf,Ta,W,Tl,Pb,Bi等在大多数标样中在三种取样量下都可以得到满意的回收率。而Sc,Cr,Ga,Y,REE,Rb,Cs,Sr,Ba,Th,U等元素在大部分样品中则随取样量减少，回收率上升，在一些样品中，当取样量降至25mg时，可以获得满意的回收率。用王水代替HNO3复溶残渣，利用氯离子的络合作用促进复溶，使许多元素的回收率有了明显的提高。     

老年高血压患者头发中6种元素含量测定及分析

对探讨老年高血压与微量元素的关系,测定了40例老年高血压患者头发中Zn、Fe、Cu、Ca、Mn、pb含量。结果表明,高血压患者头发中Zn、Fe、Cu、Ca、Mn含量均降低,以Zn、Fe、Ca降低最明显（P＜0．01）。提示发Zn、Fe、Ca对高血压发生起一定的作用。     

激光探针等离子质谱法分析岩石样品时相对元素响应及基体效应

研究了ＬＡＭ－ＩＣＰ－ＭＳ法分析岩石样品时以＾４３Ｃａ和＾５５Ｍｎ为内标的相对元素响应因子特征并进行了对比。以＾４３Ｃａ为内标不能消除ＬＡＭ－ＩＣＰ－ＭＳ分析中的基体效应,而以＾５５Ｍｎ为内标可明显地减弱基体效应的影响。测定了６个日本火成岩岩石标样中的３２个微量元素,除个别样品（如ＪＧ－３）和少数轻质量元素Ｐ、Ｓｃ、Ｃｒ以及重稀土元素Ｄｙ、Ｅｒ、Ｙｂ等外,绝大多数微量元素的分析值与标准植的相对偏差     

头发元素分析的科学意义及医学应用价值

对近100年来头发元素分析发展历史作了简要回顾，并从头发元素水平代表身体元素总体水平、头发元素含量可以准确测定，以及头发元素分析可用于医学诊断等三个方面论述了头发元素分析的生物学基础及临床意义，重点介绍了中国科学工作者在实验研究和临床实践中的探索和发现。科学实践证明，头发元素分析不仅为揭开古代头发神话提供了解释基础，也为头发的现代应用提供了可靠工具和科学依据。     

基于混合式教学和形成性评价的仪器分析实验教学改革与实践

在仪器分析实验课程中进行了基于混合式教学和形成性评价的实验教学改革。结果表明：教改组学生的自主学习能力、学习兴趣和动手能力都得到了提高;教改组学生的课程成绩总体优于对照组,t检验（p<0.05）说明2个组的成绩具有显著性差异。可见混合式教学模式和形成性评价体系有利于拓展学习空间,激发学生学习兴趣,培养学生自主学习能力,全面、客观评价学习效果。     

不同产地侧柏叶中微量元素的测定分析

用等离子体发射光谱法（ICP－AES）测定了中草药侧柏叶中微量元素的含量。结果表明，侧柏叶含有多种直接参与组织代谢的微量元素，不同产地侧柏叶中微量元素的含量不同。     

邻苯二甲酸二(2-乙基)己酯和偏苯三酸三辛酯在临床不同药液中溶出量的比较

聚氯乙烯(PVC)材质的医疗器械产品中需要加入增塑剂以改善柔韧性,目前最常用的增塑剂是邻苯二甲酸二(2-乙基)己酯(DEHP)和偏苯三酸三辛酯(TOTM)。本文考察了PVC一次性使用输液器产品在脂溶性药液(紫杉醇注射液)、肠外营养液(脂肪乳)、酸性药液(左氧氟沙星,pH 3.0~5.0)和碱性药液(呋塞米,pH 8.0~9.0)中的DEHP和TOTM溶出量,并进行对比分析。先建立了一种高效液相色谱-紫外检测(HPLC-UV)方法测定增塑剂的溶出量,并利用该方法对增塑剂的溶出量进行了分析。实验结果表明,增塑剂在不同药液中均有一定的溶出情况,其中紫杉醇注射液对增塑剂的溶出量要高于脂肪乳,并远高于左氧氟沙星和呋塞米注射液。通过对比DEHP和TOTM的溶出量可以看出,在相同的浸提条件下,TOTM的溶出量远低于DEHP的溶出量。利用紫杉醇注射液浸提24 h,PVC输液器产品DEHP的溶出量为21.14 mg,而TOTM的溶出量仅为0.078 mg。DEHP的溶出量为TOTM溶出量的270倍。因此,TOTM具有的较好耐迁移性,是一种潜在的DEHP替代增塑剂。     

传统藏药材波棱瓜的微量元素分析

对传统藏药材波棱瓜中12种微量元素进行了分析。结果显示，在波棱瓜中人体必需微量元素Cu、Fe、Zn、Mn、Co、Ni、Cr、Se等含量较高；对西藏地区不同产地的波棱瓜中的微量元素含量作比较，有极显著差异。提示在选用药材时，应重视其产地。     

Plastified poly(ethylene terephthalate) (PET)-toner microfluidic chip by direct-printing integrated with electrochemical detection for pharmaceutical analysis

Rapid separation and determination of acetaminophen and its hydrolysate with end-channel electrochemical (EC) detection integrated on a plastified poly(ethylene terephthalate) (PET)-toner microchip capillary electrophoresis (CE) system was investigated. In this separation and detection system, a Pt ultramicroelectrode integrated on a three-dimensional adjustor was used as working electrode. Factors influencing the separation and detection were investigated and optimized. Results show that acetaminophen and p-aminophenol can be well separated within 84 s with R.S.D. < 1% for migration time and R.S.D. < 3.6% for detection current for both analytes. Detection limits for both analytes are determined to be 5.0 μM (S/N = 3). This method has been successfully applied to the detection of trace p-aminophenol in paracetamol tablets. The results demonstrate that the PET-toner microchips can obtain better performance than PDMS microfluidic devices but at much lower cost.     

Diamond paste-based electrodes for determination of Cr(III) in pharmaceutical compounds

A new class of monocrystalline diamond paste-based electrodes is proposed for the determination of chromium(III) at trace levels in vitamins. Three types of monocrystalline diamond—natural diamond 1 (natural diamond), synthetic diamond 50 (synthetic-1), and synthetic diamond 1 (synthetic-2)—were used for electrode construction. The linear concentration ranges are between 10^–10 and 10^–8; 10^–9 and 10^–7, and 10^–10 to 10^–8 mol L^–1, with limits of detection of 10^–12, 10^–12, and 10^–11 mol L^–1, when natural diamond, synthetic-1, and synthetic-2, respectively, are used as electrode materials. For electrodes based on natural diamond and synthetic-1 it was found that Cr(III) yields a peak at about +0.275±0.015 V (vs. Ag/AgCl) within a predetermined positive potential range situated between +0.4 and +0.2 V, while for the electrode based on synthetic-2 the peaks are found at +0.300±0.015 V (vs. Ag/AgCl). The proposed method is reliable for the determination of chromium(III) at trace levels in two vitamin tablets (RSD<0.2%).     

Raman imaging analysis of pharmaceutical tablets by two-dimensional (2D) correlation spectroscopy

Chemical properties of active substances and insoluble excipient within tablets such as crystalline structures can be seen as an important index for solubility of ingredients. Spectroscopic imaging can potentially be a solid solution to understanding mechanisms at the molecular level and it may bring useful insight in terms of process analytical technique. In the present study, generalized two-dimensional (2D) correlation spectroscopy is utilized for the Raman image analysis of pharmaceutical tablets to reveal molecular interactions between chemical components. By using a spatial distance as a perturbation variable in 2D correlation scheme, synchronous and asynchronous correlation analysis becomes possible. Two kinds of pharmaceutical tablets, pentoxifylline (PTX) as an active substance and palmitic acid (PA) as an insoluble excipient, are prepared with different grinding times, 0.5 and 45 min. The 2D correlation analysis of Raman images of the tablets clearly reveals both physical and chemical effects of grinding process on the properties of the tablets. Asynchronous correlations indicate that a specific molecular structural change of PTX related to the crystallinity is induced by the grinding process. Namely, the crystallinity of PTX based on CH₂ structure is a key factor to control the solubility of the tablets. Some properties of pharmaceutical tablets, i.e. solubility or distribution of components in turn may become possible by the simple grinding process. Detailed analysis of Raman images becomes possible by the 2D correlation spectroscopy.     

Determination of trace amounts of chromium (VI) by flow injection analysis with chemiluminescence detection

A new sensitive chemiluminescence (CL) method combined with continuous flow injection analysis is described for the determination of Cr(VI). Strong CL signals were generated by Cr(VI)-catalysed oxidation of gallic acid in the presence of potassium permanganate and hydrogen peroxide. Effects of reagent concentrations, temperature, pH, flow rates, mixing coil length and mixing flow sequences on the chemiluminescence intensity were studied. Under the optimised experimental conditions, the relationship between the logarithm of concentration (log?C) of Cr(VI) and the logarithm of intensity (log?I) is linear over the range of 2?×?10^?11 – 5?×?10^?4?mol?L^?1, with the detection limit (3σ) of 4?×?10^?12?mol?L^?1. Relative standard deviation of ten measurements of 1?×?10^?9?mol?L^?1 Cr(VI) is 1.7%. This flow injection analysis (FIA) system proved to be able to analyse up to 40 samples h^?1. Effects of various interferences possibly present in the water samples were investigated. Most cations and anions, as well as organic compounds, did not interfere with the determination of Cr(VI) in water samples. The experimental results obtained for chromium in reference materials were also in good agreement with the certified values.     

Enhancement of on chip chemiluminescence signal intensity of tris(1,10-phenanthroline)-ruthenium(II) peroxydisulphate system for analysis of chlorpheniramine maleate in pharmaceutical formulations

The effect of detection chip geometry on chemiluminescence (CL) signal intensity of tris(1,10-phenanthroline)-ruthenium(II) peroxydisulphate system for analysis of chlorpheniramine maleate (CPM) in pharmaceutical formulations was investigated. It was observed that the design of the detection chip is very crucial and can play an important role in enhancing the CL signal intensity in this system. The CL signal intensity was enhanced 250% when a teardrop micromixer chip was used, compared to the commonly used serpentine chip geometry. The study was conducted using a multi-chip device. In this device, chip 1 was used to prepare and pump the reagent mixture, whereas chip 3 was used for pumping the sample. The two chips were connected to the teardrop chip (2) via silica capillary where detection took place. Non-linear regression curve fitting of the calibration data revealed that the calibration curves are best described by third order polynomial equation with excellent correlation coefficients (R² = 0.9998) for the concentration range 7.69 × 10⁻⁸ to 5.12 × 10⁻⁵ mol L⁻¹. A linear response is also observed over the range 7.69 × 10⁻⁸ to 1.28 × 10⁻⁵ mol L⁻¹ (R² = 0.9996) and the detection limit was found to be 5.49 × 10⁻⁸ mol L⁻¹. The device was successfully used for the analysis of CPM in tablets and a multi-component cough syrup. Results were reproducible with relative standard deviation (RSD) of 0.6-1.1%.     

Membrane sensors for batch and flow injection potentiometric determination of ethamsylate (cyclonamine) in pharmaceutical preparations

The lipophilic nickel(II) and iron(II) bathophenanthroline derivatives of ethamsylate are used as ion-exchangers with high selectivity characteristics for ethamsylate. Poly(vinyl chloride) membrane sensors incorporating these electroactive materials display fast linear response for 1 × 10^–1–1 × 10^–4 M ethamsylate under static and hydrodynamic modes of operation. In an acetate buffer of pH 4, the calibration slope is 51–53 mV/concentration decade and the lower limit of detection is 5.3 g/ml. Except for salicylate and nitrate, most common anions, organic sulfonates, carboxylates, phenolates and various pharmaceutical excipients and diluents do not interfere. Determination of ethamsylate in various dosage forms shows an average recovery of 98.9% of the nominal and a mean standard deviation of 0.7%.     

Comparison and evaluation of analysis procedures for the quantification of (2-methoxyethoxy)acetic acid in urine

Several extraction and derivatization procedures were evaluated for the quantification of (2-methoxyethoxy)acetic acid (MEAA) in urine. MEAA is a metabolite and a biomarker for exposure to 2-(2-methoxyethoxy)ethanol, a glycol ether with widespread use in various industrial applications and the specific use as an anti-icing additive in the military jet fuel formulation JP-8. Quantification of glycol ether biomarkers is an active area of analytical research. Various sample preparation procedures were evaluated: liquid–liquid extraction (LLE) using ethyl acetate yielded the highest recovery, and solid-phase extraction (SPE) gave low recovery of MEAA. Two derivatization procedures were thoroughly investigated and validated, namely, silylation of MEAA with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), and esterification of MEAA using ethanol. Quantification was performed by gas chromatography (GC) with a mass spectrometer as detector and using a polydimethylsiloxane (HP-1) capillary column. Deuterated 2-butoxyacetic acid (d-BAA) was used as an internal standard. Recovery studies of spiked human urine demonstrated the accuracy and precision of both procedures. The limit of detection (LOD) and other figures of merit for both derivatization procedures will be discussed in detail. Applications of these analysis procedures are also discussed. Disclaimers Mention of company names and/or products does not constitute endorsement by the Centers for Disease Control and Prevention (CDC). The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.