熔融萃取法富集痕量铂和铑—石墨炉原子吸收光谱测定

本文报道以２－巯基苯并噻唑（ＭＢＴ）为络合剂，用熔融萘萃取痕量的铂和铑，继用石墨炉原子吸收光谱法直接测定之。文中曾对一些有关参数作了试验，并找出各参数的最优值。对共存离子的允许量也作了试验。最后用国家标样和部级管理样核对本法，结果令人满意。     

ICP-AES法测定钢中酸溶铝和酸不溶铝及全铝

应用ICP－AES法测定了钢中酸溶铝和酸不溶铝，并对测定条件及相关参数进行了试验和优化，并于基体的干扰及方法的准确度和精密度也作了研究并标准物质作了验证。用此法所测得结果与标准物质的证书值间无显著差异，将酸不溶铝和酸溶铝的测得值相加即得总铝的量。     

ICP-AES测定钼铁中微量锑和锡

讨论了CID作检测器，ICP－AES测定钼铁中微量锑和锡，选择了最佳分析谱线和仪器重要参数，通过试验大量钼和铁的影响，用铁量匹配绘制校准曲线对试样进行直接测定的方法，检出限锑为0．0011％，锡为0．0004％，回收率为99％－103％。     

中药道地性微量元素鉴定法的方法学探索

探讨和发展了用元素指纹谱法，特征参数和关联系数法鉴定中药道地性的方法，研究表明，如果选择合适的参数或对数据作适当预处理，利用微量元素鉴别中药是可能的，并介绍了这三种方法的特点。     

微波消解试样-电感耦合等离子体质谱测定水系沉积物中钨和钼

用电感耦合等离子体质谱法测定水系沉积物试样中钨和钼的量,试样用硝酸和氢氟酸在MARS 5型微波消解仪中作消解处理。对仪器的工作参数做了试验并予以优化,测得方法对钨及钼两元素的检出限(3s/k)依次为0.03,0.07μg.g-1。通过分析4个水系沉积物标准物质对所提出方法的准确度和精密度作了考核,所测得钨和钼的结果均与4个标准物质的认定值相一致,各测定值的相对标准偏差(n=7)均小于8.5%。     

反相高效液相色谱法测定阿莫西林

采用反相高效液相色谱法测定阿莫西林并对测定条件及有关参数进行了试验.用Shim-Pack VP-ODS柱作色谱柱,以磷酸盐缓冲液(pH 5.0)及乙醇以90比10的混合液为流动相,流速为1.0 mL·min-1,在228nm波长处测定阿莫西林的含量,其线性范围为0.045～0.60 g·L-1,相关系数为0.9974.将方法应用于阿莫西林胶囊的测定,测定结果的相对标准偏差值小于0.6%,用标准加入法作回收试验,回收率结果在94.7%～101.3%之间.     

一种半经验的关联-预测活度系数的系统

提出一种半经验的关联-预测活度系数的系统。二元系的活度系数用一过量自由焓模型推算。该模型的模型参数从2个代数方程联立求解, 其一关联模型参数与γ^∞, 另一关联模型参数与(dγ-dx)x=0。γ^∞用MOSCED模型由纯组分性质关联。(dγ/dx)x=0用三维溶解度参数关联。用该系统对145组等温极性二元系作了预测, 对计算结果与实验值作了对比。F0T6R19     

顺丁烯二酸二异辛酯的合成

以顺丁烯二酸酐和异辛酯为原料，用对甲苯磺酸作催化剂合成顺丁烯二酸二异辛酯。用正交试验确定了酯化反应的优化条件，酯化率达97．96％．     

程序升温热重法研究扎赉诺尔煤的气化动力学

用程序升温热重法对扎赉诺尔煤（ＺＬ）的８００℃半焦进行ＣＯ２气化研究，考察了升温速率对ＴＧ／ＤＴＧ谱图的影响，分析讨论了ＤＴＧ参数（Ｔｍ和Ｒｍ）的变化；用单一升温速率法和多个升温速率组合法分别作了动力学计算，并对结果进行了分析讨论。结果表明：Ｔｍ和Ｒｍ均随升温速率的增高而增大，两种计算方法得到的动力学参数是不同的，单一升温速率法计算出的表观活化能Ｅ和指前因子Ａ遵循关系式：ｌｏｇＡ＝０．１０Ｅ－８．     

5—Br—PADAP作指示剂络合滴定法连续测定矿石中的锌和铜

本文在ｐＨ５．５的乙酸－乙酸钠介质中，对以５－Ｂｒ－ＰＡＤＡＰ作指示络合滴定法连续测定锌和铜进行了研究，对滴定的ｐＨ值及指示剂用进行了选择，试验了锌，铜不同配比的滴定结果，研究了共存离子的干扰。实验表明，用５－Ｂｒ－ＰＡＤＡＰ作指示剂，ＥＤＴＡ作滴定剂连续和铜，滴定点颜色变化敏锐，准确度高，锌和铜均在０－２０ｍｇ范围内与ＥＤＴＡ用量成正比，锌，铜比例在１：１０－１０：１范围内相互无影响。方法用于标     

Novel Sampling for the Determination of Naphthalene in Air by Gas Chromatography–Mass Spectrometry

Here are reported two new sampling method approaches for the determination of naphthalene in ambient air for concentrations from 0.25 to 18.7?µg/L. The first method used for gas phase naphthalene analysis produced an average recovery of 88.8% and the second method using headspace sampling produced an average recovery of 93.8%. The second method showed better recovery than the former, so it was used for subsequent comparative gas-phase determination of naphthalene. The second method was validated at various naphthalene concentrations and humidity using a naphthalene gas generator to produce various naphthalene standards and a naphthalene-monitoring instrument. The naphthalene concentrations generated using the gas generator and determined second sampling method with gas chromatography–mass spectrometry (GC–MS) were compared to the sensor measurements and were in good agreement. In summary, the sampling methods presented provided reliable gas-phase naphthalene determination when coupled with GC–MS.     

Spectrophotometric determination of palladium after solid-liquid extraction with 1-(2-Pyridylazo)-2-naphthol at 90 degrees C

An effective spectrophotometric determination of palladium with 1-(2-pyridylazo)-2-naphthol (PAN) using molten naphthalene as a diluent has been studied. A green complex of palladium with PAN is formed at 90 degrees C. In the range of pH 1.5-7.5, the complex is quantitatively extracted into molten naphthalene. The organic phase is anhydrously dissolved in CHCl(3) to be determined spectrophotometrically at 678 nm against the reagent blank. Beer's law is obeyed over the concentration range of 0.5-10 ppm. The molar absorptivity and Sandell's sensitivity are 1.2 x 10(4) l mol(-1) cm(-1) and 0.0070 mg cm(-2), respectively. The optimum conditions for determination are obtained. The interferences of various ions are observed in detail. The method has been applied to the determination of palladium in synthetic samples.     

Preconcentration of Indium(III) from Complex Materials After Adsorption of Its Morpholine-4-dithiocarbamate on Naphthalene or Using Morpholine-4-dithiocarbamate-cetyltrimethylammonium Bromide-naphthalene Adsorbent

Abstract

A highly selective, sensitive and rapid differential pulse polarographic method has been developed for the estimation of trace amounts of indium in standard alloy, ore, synthetic and environmental samples. The morpholine-4-dithiocarbamate of indium(III) is adsorbed on microcrystalline naphthalene in the pH range 3.5–6.4. The metal complex is desorbed with HCl and determined with a differential pulse polarograph (DPP). This metal may alternatively be quantitatively retained on morpholine-4-dithiocarbamate-cetyltrimethylammonium bromidenaphthalene adsorbent packed in a column at a flow rate of 0.5–5.0 ml/min and determined similarly. The detection limit is 0.10 ppm at the minimum instrumental setting (signal to noise ratio = 2). Indium has been determined in the concentration range 0.70–15.0 ppm with a correlation factor of 0.9996 and a relative standard deviation of 0.76% (n = 8). In the column method, the linearity is maintained in the concentration range 0.70–8.5 ppm with a correlation factor of 0.9994 and a relative standard deviation of 0.89% (n = 8). Various parameters, such as the effect of pH, volume of aqueous phase, reagent, and naphthalene concentrations and interference of a large number of metal ions and anions on the estimation of indium have been studied in detail to optimize the conditions for its trace determination in various complex materials.     

固相萃取ICP-AES法测定多种微量元素的研究

建立了以微晶萘作为吸附载体的固相萃取ＩＣＰ－ＡＥＳ法测定微量Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ｃｄ、Ａｌ、Ｍｎ的新方法。研究了溶液酸度、试剂浓度、萘用量以及共存离子对待测物回收率的影响。方法可用于生物标样品的测定,分析结果满意。     

固相萃取ICP-AES法测定多种微量元素的研究

建立了以微晶萘作为吸附载体的固相萃取 Ｉ Ｃ Ｐ Ａ Ｅ Ｓ 法测定微量 Ｆｅ 、 Ｃｏ 、 Ｎｉ、 Ｃｕ 、 Ｚｎ 、 Ｃｄ 、 Ａｌ、 Ｍｎ 的新方法。研究了溶液酸度、试剂浓度、萘用量以及共存离子对待测物回收率的影响。方法可用于生物标准样品的测定,分析结果满意。     

Column preconcentration of trace manganese with the ion pair of 2-nitroso-1-naphthol-4-sulfonic acid tetradecyldimethylbenzyl-ammonium chloride supported on naphthalene and determination by derivative spectrophotometry

A column preconcentration method has been developed for the determination of trace amounts of manganese by preconcentration on 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S)-tetradecyldimethylbenzylammonium (TDBA) naphthalene as an adsorbent using a simple funnel tipped glass tube. Manganese reacts with nitroso-S to form a water soluble brown colored chelate anion. The chelate anion forms a water insoluble Mn-Nitroso-S-TDBA ion pair on naphthalene packed in a column in the pH range 9.6-10.5 at a flow rate of 1-2 ml/min. The solid mass consisting of manganese complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal determined by second derivative spectrophotometry. The calibration curve is linear in the concentration range 0.25-35.0 micrograms of Mn in 5 ml of the final DMF solution. Eight replicate determinations of 25 micrograms of standard manganese solution give a mean peak height of 4.0 with a correlation coefficient of 0.9995 and relative standard deviation of +/- 1.1%. The sensitivity was calculated to be 0.502(d2 A/d lambda 2)/microgram ml-1 from the slope of the calibration curve. The detection limit was 0.020 microgram ml-1 for manganese at the minimum instrumental settings (signal to noise ratio = 2). Various parameters effecting the method such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of manganese have been evaluated to optimize the conditions for its determination in standard alloys and biological samples.     

ENERGY TRANSFER FROM MICELLAR SODIUM PHENYLUNDECANOATE TO SOLUBILIZED NAPHTHALENE

Abstract— Excitation energy transfer from the phenyl groups of surface active phenylundecanoate ions to naphthalene molecules has been studied under conditions such that the naphthalene molecules have been solubilized by micelles of phenylundecanoate. From measurements of the naphthalene fluorescence intensity in solutions of varying surfactant concentration the critical micelle concentration has been determined as 0·0091 M. The product of the micellar aggregation number and the efficiency of energy transfer has been obtained as 75 from measurements of both the sensitized naphthalene fluorescence and the quenching of the phenylgroup fluorescence. In the evaluation of the experimental data it has been assumed that the partition of naphthalene between the micelles and the aqueous phase may be treated as a distribution equilibrium, and that the solubilized naphthalene molecules are partitioned among the micelles according to a Poisson distribution. With this model, the naphthalene fluorescence intensities may be accounted for over the whole range of surfactant concentrations.
At high naphthalene concentrations, emission from naphthalene excimers has been observed. The possibility of self-quenching via excimer formation is considered.
The experimental results point to a quantum efficiency near unity for the transfer of excitation energy from the phenyl groups of the surfactant ions that form a micelle to a single solubilized naphthalene molecule. The high efficiency suggests that the naphthalene molecule and the phenyl groups are present inside the micelles.     

十八烷基键合硅胶的原子层沉积法封尾及其在碱性化合物分离中的应用

采用原子层沉积法对十八烷基键合硅胶进行端基封尾.以六甲基二硅氮烷为封端试剂,在250 ℃下与键合硅胶样品反应6 h,制备了对碱性化合物具有高惰性的反相色谱填料.分别以吡啶/苯酚和萘/阿米替林为分子探针,考察了经原子层沉积法和传统液相有机溶剂法封尾处理的十八烷基键合硅胶的色谱性能,并与商品十八烷基硅胶Zorbax SB-C18和Kromasil C18进行对比.结果表明,原子层沉积法封尾的十八烷基硅胶对碱性化合物的分离特性明显优于传统液相法,其色谱性能已超过Zorbax SB-C18,与Kromasil C18相当.本方法无需有机溶剂,操作简便,反应耗时短,易于放大生产,封尾反应完全,应用前景良好.     

Column Preconcentration of Palladium Using Phenanthrenequinonedioxime Supported on Naphthalene by Atomic Absorption Spectroscopy

Abstract

A solid chelating compound, phenanthrenequinonedioxime(PQDO) supported on naphthalene provides a rapid and economical means of preconcentration of palladium from the aqueous samples. Palladium forms a complex with PQDO supported on naphthalene in the column at pH 1.2～2.7. The metal complex and naphthalene are dissolved out from the column with 5 ml of dimethylformamide-nitric acid (100+4) and the absorbance is measured atomic absorption spectrometer at 244.7 nm. A calibration curve is linear over the concentration range 1～24 μg of palladium in 5 ml of the final solution. The sensitivity for 1% absorption is 0.126 μg/ml (0.153 μg/ml for the direct AAS method from the aqueous medium). The method has been used for the determination of palladium in various synthetic samples and can be safely applied to the environmental samples too.     

Trifluoroethylxanthate as an Analytical Reagent: AAS of Zinc,Antimony and Lead After Coprecipitation of Their Trifluoroethylxanthates onto Microcyrstalline Naphthalene

Abstract

A sensitive method has been developed for the direct atomic absorption spectrometric determination of zinc, antimony and lead after coprecipitation of their trifluoroethylxanthates onto microcrystalline naphthalene. The metal xanthates are quantitatively coprecipitated over the pH ranges: Zn, 5.9–8.4; Sb, 4.0–6.0 and Pb, 4.0–11.0. The solid mass consisting of the metal complex and naphthalene is dissolved in DMF. This solution is aspirated into an air-acetylene flame at 213.9, 217.6 and 217.0nm for Zn, Sb and Pb, respectively. Beer's law is obeyed in the concentration range 2–50, 3–90 and 5–60 μg of Zn, Sb and Pb, respectively in 10ml of the final DMF solution. RSDs are at the ± (0.5–0.6)% level (n=10). The concentration for 1% absorption is 0.019, 0.035 and 0.060μg/ml for Zn, Sb and Pb, respectively. The method is suitable for the preconcentration of the metals from a larger volume of the aqueous phase, and has been employed for their determination in standard reference materials. It may be employed for the simultaneous determination of Zn, Pb and Sb in a solution by pH control.