Trace determination of cobalt ion by using malic acid-malonic acid double substrate oscillating chemical system

A novel kinetic method for determination of trace amounts of cobalt ion was proposed and validated. The method is based on adding malic acid into classical Belousov-Zhabotinskii （B-Z） oscillating chemical system to form a double substrate one. The results showed that when the concentration of cobalt ion was in the range of 5.27× 10^-8 to 5.37 × 10^-12 mol L^-1, the change of the oscillating period was directly proportional to the negative logarithm of cobalt ion concentration. The sensitivity and precision of the developed method were quite satisfactory. The limit of detection was down to 5.20 × 10^-13 mol L^-1 which was a highest sensitivity found for determination of metal ions using oscillating chemical reaction so far. Some factors influencing the determination were also examined. The method has been successfully used to determine cobalt ion in vitamin B12 injection.

Chemical Analysis Method for Carbon Bearing Refractory Products——Determination of the Total Carbon by Combustion Gravimetric Method

GB/T 13245-91 1 Theme and Scope This standard specifies the method abstract, reagents, apparatus, specimen, analyzing procedure, result calculation and permissible tolerance used for determination of the total carbon with combustion gravimetric method.

Chemical Analysis Method for Magnesia and Magnesia-Alumina Refractories——Gravimetric-Molybdenum Blue Photometric Method for Determination of Silicon Dioxide Content

This standard specifies the gravimetric-molybdenum blue photometric method for determination of silicon dioxide content.

Identification of variety of rice and determination of content of each rice in mixtures of two rices by nonlinear chemical analysis

Fingerprints of two varieties of rice and their mixtures were investigated by a nonlinear chemical reaction system consisting of rice components,sodium bromate,manganese sulfate,sulfuric acid and acetone.The variety of rice was identified by the visual characteristic of fingerprint and system similarity pattern recognition,and the content of each variety of rice in the mixture was determined by the quantitative information of fingerprint.The results show that nonlinear chemical analysis may be used to exactly identify the variety of pure rice and to accurately determine the content of each variety of rice in the mixture,indicating the method is simple and convenient.

Chemical Analysis Method for Carbon Bearing Refractory Products——Determination of Magnesium Oxide Content by CyDTA Volumetric Method

This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.

Chemical Analysis of Magnesia and Magnesia-Alumina Refractory Materials——Gravimetric method for determination of loss on ignition

1 Scope This standard specifies the gravimetric method for determination of loss on ignition.

Chemical Analysis of Magnesia and Magnesia-Alumina Refractory Materials——Flame atomic absorption spectrometric method for determination of calcium oxide content

1 Scope This standard specifics the determination of calcium oxide coutent by flame atomic absorption spectrometric method.

Chemical Constituents from Roots of Semiaquilegia adoxoides

Semiaquilegia adoxoides ( DC. ) Makino ( Chinese name ''Tian-Kui-Zi'' ) , theonly species of genus Semiaquilegia, belongs to the Ranunculaceae family. As a perennial herbaceousplant, both the aerial parts and the roots are used in traditional Chinese medicine for differentmedications. The roots are often used to treat inflammation, snake bite, bruises and injuries,tonsillitis, mastitis, scrofula, and cancer for their antibacterial, anti-inflammatory, andantineoplastic activities. The aerial parts are used for the treatment of mastitis, bruises, andheart diseases, such as endomyocarditis. The medicinal usage of this plant prompted us toinvestigate its chemical constituents. As a result, nine compounds 1-9 ( see Figure 1) were isolatedfrom the roots of S. adoxoides. Among them, compounds 1-7 and 9 were isolated from the genusSemiaquilegia for the first time.

Preparation and Electrochemical Properties of 3-Pyridinyl-6-aryl-1,2,4-triazolo [3,4-b][1, 3,4]thiadiazoles

A series of 3-pyridinyl-6-aryl-l, 2, 4-triazolo[3, 4-b][1, 3, 4]thiadiazoles(PATT) were prepared, the structures were confirmed by IR and H NMR spectra. The results of cyclic 1 voltammetry measurements imply that all these compounds have a higher electron affinity (EA) than 2-(4-biphenyl)-5-(4-tert-butyl phenyl)-1, 3, 4-oxadiazole (PBD) which implies that PATT could be acting as better electron acceptors than widely used electron transporting material PBD.

Indirect Differential Pulse Voltammetric Determination of Aluminum by a Pyrocatechol Violet-Modified Electrode

A PCV-modified electrode was simply prepared by dip-coating a pyrolytic graphite electrode in a NaAc-HAc buffer solution of PCV. The peak currents of differential pulse voltammograms (DPV) decrease with the addition of Al and the peak potentials remain the same. The decreasing of Delta i(p) is linear with Al concentration in the range of 1 x 10(-8) similar to 1 x 10(-7) mol/L. The detection limit is 5 x 10(-9) mol/L and the relative standard deviation for 4 x 10(-8) mol/L Al is 2.9% (n=8). No serious interference was found. The determination of Al in water samples is reported.

Soil Chemical Analysis of Kazi and Kazi Organic Tea Garden and Compared to Ordinary Tea Gardens of Bangladesh

Tea is grown in Bangladesh under marginal climatic and soil conditions. Its production is greatly influenced by many physical, chemical, biological and natural factors. The increasing land use intensity without adequate and balanced use of chemical fertilizers and with little or no use of organic manure has caused severe fertility deterioration of our soils resulting in stagnating or even declining of crop productivity. The need of the hour is to achieve substantially higher crop yield than the present yield levels from our limited land resources on a sustainable basis. A feasibility study was carried out of one and only organic tea garden namely Kazi & Kazi Tea Estate at Panchaghar and compared to ordinary tea gardens located at Sylhet namely Zareen Tea Estate, Nurjahan Tea Estate and Malnichara Tea Estate as secondary data to investigate the fertility status of soil. Results of the present study showed that soil solutions were acidic in nature in all seasons. Medium to high soil organic matter, medium to high available iron and phosphorous, and low availability of potash showed that soils were not sufficiently fertile for crop production. Student t-test values of all the parameters with control sample showed statistically significant results for SOM and available P. The critical values have been fixed at 0.1% for N and 1% for OM, 10 μg/g for P, 80 μg/g for K, 25 μg/g for Mg, 90 μg/g for Ca, 2 μg/g for Zn and 20 μg/g for S. The nutrient status is much higher in Kazi & Kazi organic tea estate in compared to other ordinary tea estates in Bangladesh.

清肝润肺止咳露高效液相色谱特征图谱、含量测定及化学模式识别的研究

目的建立清肝润肺止咳露高效液相色谱(HPLC)特征图谱,测定其中吗啡、可待因、罂粟碱、那可丁的含量,并结合化学模式识别方法,综合评价该制剂的质量。方法采用HPLC法,以甲醇-5μmoL·L^(-1)庚烷硫酸钠溶液(用磷酸调节pH至2.6)为流动相进行梯度洗脱,流速:1.0 mL·min^(-1),柱温:20℃,检测波长:220 nm,进样量:10μL。利用指纹图谱相似度评价软件,结合聚类分析(CA)、主成分分析(PCA)和偏最小二乘法判别分析(PLS-DA)对10批清肝润肺止咳露的特征图谱进行评价。结果10批清肝润肺止咳露特征图谱共确定16个共有峰,指认了5个共有峰,分别为吗啡、可待因、蒂巴因、罂粟碱、那可丁。其中4个成分在线性范围内(吗啡0.70~8.70μg、可待因0.68~8.50μg、罂粟碱0.60~7.55μg、那可丁0.38~4.80μg)均有良好的线性关系(r≥0.9997);精密度、稳定性、重复性试验的RSD均小于3.0%;平均加样回收率在97.93%~99.43%之间(RSD<3.1%);含量测定结果:吗啡43.58~76.47μg·mL^(-1),可待因16.64~78.92μg·mL^(-1),罂粟碱29.93~41.22μg·mL^(-1),那可丁14.44~33.22μg·mL^(-1)。通过CA、PCA和PLS-DA分析,可将10批清肝润肺止咳露分为2类(S3、S4、S8、S10聚为一类,其余聚为一类),并筛选出峰2、峰4、峰13、峰11(吗啡)、峰1、峰10、峰8、峰12、峰16(那可丁)9个差异性成分。结论该研究建立的HPLC特征图谱及含量测定方法简单、准确,结合化学模式识别法,可用于清肝润肺止咳露的质量控制。

HPLC指纹图谱结合多成分含量测定评价香附质量

目的建立香附药材的高效液相色谱(High performance liquid chromatography,HPLC)指纹图谱,结合4种化学成分含量对不同产地及用药规格香附的质量进行综合评价。方法采集HPLC指纹图谱,并结合聚类分析(Cluster analysis,CA)和主成分分析(Principal component analysis,CA)等多种化学计量学方法对不同产地及用药规格的香附药材进行区分比较。利用HPLC法测定香附药材中香附烯酮、α-香附酮、木犀草素和阿魏酸的含量。结果CA和PCA分析结果显示,不同产地香附均可单独聚为一类,而浙江金华与其他产地香附差异最大,河南尉氏香附综合得分最高,质量较优;正交偏最小二乘法判别分析(Orthogonal partial least square-discriminant,OPLS-DA)结果显示,指纹图谱中13号峰(α-香附酮)、10号峰(香附烯酮)和14号峰是不同产地间香附质量产生差异的主要成分。广东湛江和浙江金华香附中香附烯酮与α-香附酮含量较为接近,香附烯酮含量远大于河南香附,α-香附酮含量远小于河南香附;不同产地香附中阿魏酸和木犀草素含量差异不大。去皮后香附中香附烯酮、α-香附酮和木犀草素含量降低,阿魏酸含量增加。结论不同产地间香附质量存在差异,以河南香附质量最佳。去皮前后香附化学成分相似,无明显种类差异。

HPLC法同时测定脑脉泰胶囊中12种成分的含量

目的建立HPLC法同时测定脑脉泰胶囊中3′-羟基葛根素、2-羟基红花黄色素A、葛根素、葛根素芹菜糖苷、3′-甲氧基葛根素、大豆苷、二苯乙烯苷、木犀草苷、染料木苷、木犀草素、丹酚酸B、迷迭香酸的含量。方法分析采用KromasilC_(18)色谱柱(250mm×4.6mm,5μm);流动相乙腈-水(含1.0g/L磷酸),梯度洗脱;体积流量0.8mL/min;柱温30℃;检测波长280nm。再进行聚类分析、主成分分析。结果12种成分在各自范围内线性关系良好(r>0.9990),平均加样回收率97.07%~98.30%,RSD0.86%~1.82%。10批样品聚为4类,4种主成分累积方差贡献率达86.262%。结论该方法简便稳定,可靠准确,可为脑脉泰胶囊的质量控制提供科学依据。

引火汤冻干粉HPLC指纹图谱建立及8种成分含量测定

目的建立引火汤冻干粉HPLC指纹图谱,并测定地黄苷D、麦冬甲基黄烷酮A、毛蕊花糖苷、原儿茶酸、梓醇、五味子醇甲、五味子乙素、五味子甲素的含量。方法指纹图谱建立采用Supersil AQ18色谱柱(4.6 mm×250 mm,5μm);流动相乙腈-0.1%磷酸,梯度洗脱;体积流量1.0 mL/min;柱温30℃;检测波长230 nm。UPLC-MS/MS含量测定采用Alphasil VC-C_(18)色谱柱(2.1 mm×100 mm,2.5μm);流动相乙腈-0.1%甲酸,梯度洗脱;体积流量0.3 mL/min;柱温30℃;电喷雾离子源;正负离子扫描;多反应监测模式。结果10批冻干粉指纹图谱中有17个共有峰,相似度大于0.90,指认出毛蕊花糖苷、水晶兰苷、去乙酰车叶草苷酸、五味子醇甲。8种成分在各自范围内线性关系良好(R^(2)>0.9906),平均加样回收率98.7%~101.1%,RSD 2.0%~5.2%。结论指纹图谱结合含量测定能完整表征引火汤基准样品质量,从而为其关键化学属性质量评价提供参考。

基于HPLC法及UPLC-MS法测定芫花饮片炮制前后7种成分的含量变化

目的:建立HPLC法及UPLC-MS法测定芫花中银椴苷、木犀草素、芹菜素、绿原酸、羟基芫花素、芫花素及芫花酯甲7种化学成分含量的方法,分析芫花炮制前后化学成分的变化。方法:采用HPLC法,测定银椴苷、木犀草素、芹菜素、绿原酸、羟基芫花素和芫花素6种成分的含量,色谱柱为Agilent Eclipse Plus C18(250 mm×4.6 mm,5μm),流动相为乙腈(A)-0.1%甲酸(B)梯度洗脱,流速为1.0 mL·min^(-1),进样量10μL。同时采用UPLC-MS方法测定芫花酯甲的含量,色谱柱为ACQUITY UPLC HSS T3 C18色谱柱(2.1 mm×100 mm,1.8μm),流动相为乙腈(A)-0.1%甲酸(B)梯度洗脱,流速0.3 mL·min-1,柱温35℃,进样量1μL。结果:7种成分的含量由高到低依次为芫花素>绿原酸>银椴苷>芹菜素>羟基芫花素>木犀草素>芫花酯甲。芫花炮制后7种成分的含量均发生一定程度的变化,其中绿原酸成分在炮制后含量有升高有降低,变化不明显;对于银椴苷和芹菜素成分,炮制后含量降低;对于木犀草素、羟基芫花素和芫花素3个成分,炮制后含量升高;对于芫花酯甲成分,炮制后含量降低。结论:该方法简便、灵敏、高效,为考察芫花饮片炮制前后的质量变化提供了技术支持。

HPLC-MS/MS法同时测定胆木不同部位6个成分的含量

目的:测定胆木茎、枝和叶中异长春花苷内酰胺、喜果苷、乌檀酰胺C、绿原酸、3,4,5-三甲氧基苯基-1-O-β-呋喃芹糖基(1→2)-β-D-吡喃葡萄糖苷、3,4-二甲氧基苯基-1-O-β-呋喃芹糖基(1→2)-β-D-吡喃葡萄糖苷6个成分的含量。方法:采用HPLC-MS/MS法,色谱柱为Phenomenex Kinete EVO C18100Å(50 mm×2.1 mm,2.6μm)柱;流动相为0.5‰甲酸溶液-甲醇,梯度洗脱;流速为0.4 mL/min;柱温为40℃;进样量为3μL;电喷雾离子源,多反应监测负离子模式。结果:异长春花苷内酰胺、喜果苷、乌檀酰胺C、绿原酸、3,4,5-三甲氧基苯基-1-O-β-呋喃芹糖基(1→2)-β-D-吡喃葡萄糖苷、3,4-二甲氧基苯基-1-O-β-呋喃芹糖基(1→2)-β-D-吡喃葡萄糖苷的线性范围分别为0.025~2μg/mL、0.0125~2μg/mL、0.05~2μg/mL、0.025~2μg/mL、0.0125~2μg/mL、0.0125~2μg/mL(r≥0.9991),精密度、稳定性(24 h)、重复性试验RSD<5.00%,平均加样回收率为95.13%~103.02%(RSD<4.00%)。含量测定结果显示6个成分在胆木不同部位中的含量存在较大差异。结论:所建立的方法简便、快速、灵敏,适用于胆木药材中6个成分的同时检测。

基于HPLC特征图谱和多成分含量评价梨干的质量

目的建立梨干的特征图谱,测定其中熊果苷、绿原酸、芦丁3种成分的质量分数,结合化学模式识别方法,综合评价其质量差异。方法采用HPLC法,乙腈-0.1%(体积分数)磷酸水溶液作为流动相进行梯度洗脱,流速:1.0 mL/min;柱温:30℃;检测波长:0~25 min,280 nm;26~90 min,350 nm;进样量:20μL。采用“中药色谱特征图谱相似度评价系统(2012版)”软件,结合聚类分析(HCA)、主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)综合评估20批梨干样本的HPLC特征图谱,同时测定其熊果苷、绿原酸、芦丁的质量分数。结果建立了20批梨干药材的特征图谱,相似度为0.959~0.997,标定了16个共有峰,同时指认了3个共有峰,分别为熊果苷、绿原酸、芦丁,其质量分数分别为16.78~66.00、47.69~260.10、1.39~5.48μg/g,绿原酸质量分数明显高于其他2种成分。通过HCA、PCA和OPLS-DA分析,把20批梨干分为2类(河北产地与非河北产地),并筛选出VIP值大于1的差异性标志成分6种,分别为峰9(绿原酸)、峰4、峰5、峰8、峰13、峰1(熊果苷)。结论本方法简便、准确,可用于梨干的质量控制。

思维导图在化学分析法中的应用——以样品金属组分钴含量的测定为例

开展化学实验技术技能大赛,宗旨是通过实验操作实现对学生知识理解和技能掌握情况的评估。其中化学分析法主要对样品进行定量分析,实验考核时知识点多、操作性强,学生在实践中有一定的难度。根据化学分析法的特点,在实践教学中引入思维导图,以样品金属组分钴含量的测定为例,探讨思维导图在化学分析法实践中的应用。实践表明:思维导图有助于学生高效、准确掌握化学分析法,提升学生实验操作的规范性,提高实验效果。

基于HPLC指纹图谱结合化学模式识别以及多指标成分定量评价前胡药材质量

基于HPLC指纹图谱和多指标成分含量测定,并结合化学模式识别,评价不同产地前胡药材质量。采用Agilent SB-C_(18)(4.6 mm×250 mm,5μm)色谱柱,以甲醇-0.5%甲酸水为流动相进行梯度洗脱,流速为0.5 mL/min,检测波长321 nm,建立指纹图谱并对4个香豆素类成分进行定量,采用聚类分析(hierarchical clustering analysis,HCA)、主成分分析(principal component analysis,PCA)、偏最小二乘法-判别分析(partial least squares discriminant analysis,PLS-DA)对不同产地前胡药材进行质量评价。结果显示16批前胡药材HPLC指纹图谱相似度为0.966~0.999,确定了21个共有峰,共指认了9个成分。通过化学模式识别分析,将16批样品聚类为三类:以安徽宁国、亳州等为主的道地产区前胡,以湖南、贵州、重庆等为主的前胡,以及高海拔云南产区的前胡,并确立8个差异性质量标志物。多指标含量测定不同产地前胡的佛手柑内酯、白花前胡甲素、白花前胡乙素、白花前胡素E含量分别为0.0167~0.1319 mg/g、6.0696~16.2255 mg/g、0.4265~2.0100 mg/g、1.3407~3.1155 mg/g。本研究所建立的指纹图谱和含量测定方法专属性强,稳定性高,分离度良好,结合化学模式可用于前胡药材的质量评价。