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聚乙二醇-锌试剂-硫酸铵体系中非有机溶剂萃取光度法测定镓 总被引:5,自引:0,他引:5
1引言非有机溶剂萃取光度法测定金属离子与传统的有机溶剂萃取光度法比较,既保持了后者提高分析方法灵敏度和选择性优点,又具有不挥发、无毒、操作简便等特点,是一种新的光度分析法。本文研究了在聚乙二醇-锌试剂-硫酸铵体系中的非有机溶剂萃取光度测定Ga(Ⅱ)的条件,将该法用于高纯铝合金中镓的测定,结果满意。2实验部分2.1主要仪器和试剂DMS-200型光度对,721型光度计。锌试剂(Zincon)溶液:3×10-4mol/L;镓标准溶液:10mg/L;聚乙二醇-2000(PEG)溶液:30%(W/V);HAc-NaAc缓冲溶液:pH3.5~6.5。所用试… 相似文献
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蓝布正挥发油化学成分的GC-MS分析 总被引:7,自引:0,他引:7
研究贵州产蓝布正(Herba Gei)挥发油的化学成分,采用水蒸气蒸馏法提取蓝布正挥发性成分,用气相色谱-质谱进行分离测定,结合计算机检索技术对分离的化合物进行鉴定,应用色谱峰面积归一化法测定各成分的相对含量;水蒸气蒸馏提取物得率是0.10%,共分离出103种成分,鉴定出40个化学成分,其主要成分为脂肪酸及其甲酯类化合物、萜烯类及其含氧衍生物等,主要有棕榈酸(13.2%)、11,14,17-二十碳三烯酸甲酯(10.4%)、亚油酸(8.6%)、石竹烯氧化物(3.9%)、丁子香酚(3.4%)和反式-植醇(3.2%)等。 相似文献
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水杨基萤光酮析相光度法测定微量铝 总被引:1,自引:0,他引:1
1引言萤光酮试剂是一类重要的有机显色剂,在分析化学中有着广泛应用,但未见水杨基萤光酮(SAF)析相光度法测定铝的报道。本文研究了铝一水杨基萤光酮(SAF)TritonX-100析相光度体系,建立了测定微量铝的方法。应用于茶叶中微量铝的测定,结果满意。2实验部分2.1主要试剂和仪器铝标准液:1g/L贮备液及2.0mg/L工作液,水杨基萤光酮溶液:O.05%乙酮溶液六次甲基四肢一盐酸缓冲液;pHS:0;Trit。fiX-100溶液:20%水溶液。721型分光光度计;pHS-2型酸度计;501型超级恒温器。2.2试验方法取2Pg铝于50mL桥相管中,加5%抗… 相似文献
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1引言毕富春等曾报道二氯菊酸-1-氰基-2-甲基-2-戊烯醇酯的气相色谱分离,但使用的样品是二氯菊酸-1-氰基-2-甲基-2-成烯醇酯的各个异构体的混合物,而且未加详细讨论。年文在合成光学活性二氯菊酯-(±)-1-氰基2-甲基-2-戊烯酸酯和(-)-1-氰基-2-甲基-2-戊烯醇的基础上,对它们的气相色谱行为进行了研究。其中顺式-(-)二组菊酸和顺式-(+)-二氯菊酸的(±)-1-氰基-2-甲基-2-戊烯酸酯的两个异构体在两种固定液上都得到很好的分离。很难两个异构体的峰面积的比值可以求得手性氰醇的%e.e.值。2… 相似文献
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Cu(Ⅱ)—茜素红S—甲基紫—聚乙烯醇体系光度测定痕量铜 总被引:6,自引:0,他引:6
提出了Cu(Ⅱ)-茜素红S-甲基紫-聚乙烯醇三元配合物体系光度法测定Cu(Ⅱ)的新方法,在聚乙烯醇存在的下,Cu(Ⅱ)-茜素红S-甲基紫形成稳定的有色配合物,通过测定该化合物的吸光度而测定Cu(Ⅱ)含量,测定了天然水样,试验表明,方法有较好的灵敏度和选择性,精密度可靠,适用于水样中痕量Cu(Ⅱ)的测定。 相似文献
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含酰胺结构的巯基自组装膜的设计与结构表征 总被引:11,自引:0,他引:11
提出了一种简便通用的合成巯基化合物的途径,以分子中的羧基CO2H为起始基团,与2-流基乙胺的氨基选择性缩合;合成了一系列具有RC(O)NHCH2CH2SH(R分别为偶氯苯衍生物,双炔衍生物及直链烷基)结构的化合物,并用接触角测量,电化学和掠角反射红外光谱(GIR-IR)等手段对这些化合物在金表面形成的自组装单分子膜进行了表征。发现4-(N-(2‘-巯基已基))酰胺偶氮苯的自组装膜表现出良好的电活性,电化学测定表面浓度为4.21×10(-10)mol·cm(-2).当R为烷基链时,随烷基链的增长,膜的致密度与有序度增加GIR-IR证明在自组装腹中CH3(CH2)6C(O)NHCH2CH2SH的C=O和N-H键与Au表面平行,分子轴线与Au表面近似垂直. 相似文献
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顶空固相微萃取-气相色谱-质谱测定水中异味化合物 总被引:20,自引:1,他引:20
采用顶空固相微萃取-气相色盐/质谱联用测定了水中常见的3种异味化合物,即2-甲基异茨醇、土腥素和β-柠檬醛。研究并讨论了纤维头的类型、盐的种类和浓度、温度、萃取时间、搅拌和解吸时间等因素对异味化合物萃取量的影响。结果表明:在水样中加入30%(W/V)的NaCl溶液,采用65μm PDMS/DVB纤维头,在搅拌的条件下,于60℃顶空萃取40min为异味化合物固相微萃取的最佳条件。在优化的条件下,使异味化合物吸附于纤维涂层后,将其在250℃高温下解吸,再用GC—MS分析。土腥素、β-柠檬醛、2-甲基异茨醇的检出限依次为1.0、1.3和1.7ng/L;其相对标准偏差分别为4.9%、8.4%和6.2%:3种异味化合物在5~1000ng/L的范围内线性关系良好,相关系数均大于0.997。因此,用该方法分析水中痕量(ng/L级)的异味化合物,结果满意。 相似文献
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The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
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Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position. 相似文献
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The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations
were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples
were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of
hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the
best fitting experimental data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6. 相似文献
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微量钙的测定方法研究进展 总被引:5,自引:0,他引:5
介绍了1995-2006年期间测定微量和痕量钙的方法,如电感耦合等离子体-原子发射光谱法、原子吸收光谱法以及离子色谱法等的工作原理和特点,并说明了其测定微量钙的应用领域。并对微量钙的测定技术进行了展望(引用文献55篇)。 相似文献
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Thermal behaviour of sodium oxo-salts of sulphur: Na2SO4, Na2S2O7, Na2S2O6, Na2SO3, Na2S2O5, Na2S2O4, Na2S2O3, Na2S3O6 and of sulphides Na2S and Na2S2 was studied on heating up to 1000°C. The experiments were performed with anhydrous compounds obtained from commercial products
by recrystallisation and dehydration. The stage mechanisms of decomposition of anionic sub-lattices of the salts have been
proposed basing on the Górski’s morphological classification of simple species. The thermal stability and the stage decomposition
mechanisms were correlated with the structure and the potential chemical properties of the salt anions. The thermal decomposition
processes were studied by means of thermal analysis, and the decomposition products were identified by means of X-ray phase
analysis. 相似文献