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8—羟基喹啉纤维微柱分离富集ICP—AES测定多种痕量元素 总被引:6,自引:0,他引:6
制备了8-羟基喹啉纤维滤纸片,作为微柱填充物,同时富集了九种痕量元素,并分离了样品中的高盐组分。富集后的痕量组分采用电感耦合等离子体原子发射光谱法测定,回收率为90-102%。 相似文献
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8—羟基喹啉—5—磺酸纤维微柱分离富集电感耦合等离子体原子发射… 总被引:1,自引:0,他引:1
本文合成了8-羟基喹啉-5-磺酸纤维滤纸片,以此做为微柱填充物同时富集了10种痕量元素,并分离了样品中的高盐组分。本方法可使痕量组分的分离与富集同步进行,因而特别适用于原子光谱测定前样品的预处理。 相似文献
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蓝藻预富集-悬浮液进样GFAAS测定水中痕量银的研究 总被引:1,自引:0,他引:1
蓝藻预富集-悬浮液进样GFAAS测定水中痕量银的研究汤又文,宋健怡,莫胜钧(华南师范大学化学系,广州,510631)关键词藻,富集,银,悬浮液,石墨炉痕量分析中,由于待测组分含量低,基体复杂,常常需要对待测组分进行预富集处理。共沉淀、电沉积、萃取与离... 相似文献
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壳聚糖富集火焰原子吸收法测定天然水口痕量镉 总被引:6,自引:0,他引:6
提出了壳聚糖分离富集火焰原子吸收法检测水中痕量镉的新方法,研究了富集的最佳条件及洗脱方法。回收率达98%,灵敏度0.021μg.L^-1。方法灵敏度高,选择性好,用于天然水中痕量镉的测定,获得满意结果。 相似文献
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本文采用微波溶样,不经分离富集,直接用标准加入ICP-MS法,测定人发标准物质中15种超痕量稀土元素。选择了最佳样品预处理条件和测定的最佳仪器参数。检出限为0.007~0.026ng/mL。用国家一级土壤标准物质(GBW07401和GBW07403)作为质控样,15种痕量稀土元素的测得值与标准值很好地吻合,相对标准偏差(RSD)为1.2%~5.4%。国家一级人发标准物质(GBW07601)中稀土元素的标准值仅有La,Ce和Y,本法测得值均落在标准值的置信区间内。其余12个超痕量稀土元素本法也取得了较为满意的结果。 相似文献
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Rare earth elements (REEs) form anionic complexes which can be separated isocratically by anion-exchange chromatography using ethylenediaminetetraacetic acid (EDTA) as the mobile phase. For easy detection and identification, inductively coupled plasma (ICP) MS was used as detection method. From pH 3.5 to 7.5, retention increases from La to Sm and then decreases again up to Lu. Above pH 8.5, the retention of the light lanthanides increased drastically. It seems that the stoichiometry and the charge of the REE-EDTA complexes change with the elution pH. This strange elution behaviour can be easily tuned for particular applications by selecting the elution pH. For example, at pH values between 5.5 and 7.5 most isobaric and polyatomic interferences which occur in ICP-MS detection of the lanthanides are eliminated. A mechanism for the stepwise formation of the REE-EDTA complexes as a function of pH is proposed. 相似文献
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A method of silver preconcentration by using a column containing Amberlite XAD-16 resin and this future determination by a flame AAS after elution is proposed. The effect of the factors such as pH, the nature of complexing agent, sample volume, flow rate, the type and concentration of elution solution on the preconcentration efficiency have been investigated. The influence of some matrix elements on the recovery of silver were also examined. It was found, that the quantitative recovery of thiocyanate complex of silver was obtained from nitric acid solution (pH 2) as 99.20+/-0.07% at the 95% confidence level. A preconcentration factor up to 75 could be obtained. The detection limit of silver was 0.047 mg l(-1). The adsorption of silver onto Amberlite XAD-16 can be formally described by a Langmuir equation with maximum adsorption capacity 4.66 mg g(-1) (0.043 mmol g(-1)). The proposed method was applied to determination of silver in standard alloy with relative error 6.25%. 相似文献
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Very fine separation of proteins by stepwise elution ion-exchange chromatography is very often a unstable process. To characterize the unstability of such processes the elution volume variations were examined by the model equation which contained the ion-exchange capacity and the number of adsorption sites. The data needed for the model calculation were obtained from gradient elution experiments. As a model separation system stepwise elution of a model protein (beta-lactoglobulin) near the isoelectric point on a weak cation-exchange chromatography column was chosen. The elution volume varied significantly with a small change in the ion-exchange capacity. It was found that the ionic strength of the elution buffer must be adjusted in order to compensate a change in the elution volume due to the ion-exchange capacity variations. The ionic strength and the pH of the elution buffer were also found to be important variables affecting the elution volume. In this model separation system, it was indicated that the pH should be within +/-0.1 unit and the ionic strength within +/-0.002 mol/l in order to meet the criteria (+/-5% elution volume variation). It is recommended that gradient elution data be obtained for predicting elution volume variations in stepwise elution. By using the gradient elution data the process diagnosis can be performed, and the important information on the process stability can be obtained. 相似文献
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用大孔吸附树脂分离利血平 总被引:1,自引:0,他引:1
以利血平的吸附量和解吸率为指标,筛选大孔吸附树脂.研究吸附和解吸的优化条件,并考察选定树脂的吸附等温线、吸附动力学、吸附和解吸性能.结果表明,将催吐萝芙木根粉浸提液蒸去乙醇且不调pH(pH 1)进行吸附,HZ-818型大孔吸附树脂对利血平的吸附量可达到9.34mg/mL.使用工业乙醇-水(80:20,pH 1.0)为解吸剂,解吸率可达99.3%.该树脂的吸附符合Langmuir吸附等温方程.吸附前期,吸附速度较快,以后速度减慢.HZ-818型树脂对利血平的吸附量大,解吸率高,通过大孔树脂吸附和解吸,利血平浓度提高50倍以上,适宜于工业化生产. 相似文献
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Trace and mg amounts of yttrium and neodymium are separated from samarium and the heavier lanthanides by elution of the latter with hydroxyethylenediaminetriacetate (HEDTA) in a chloroacetate buffer of pH 2.85 from a column containing 68 ml (20 g) of AG 50W-X4 resin of 200–400 mesh particle size. Yttrium and neodymium (and also praeseodymium, cerium and lanthanum) are retained and can be eluted with 0.01M HEDTA in 0.20M ammonium acetate (pH 6). The separations are reasonably sharp and quantitative: only 3–15 μg of samarium was found in the yttrium fraction and 0.8–3.4 μg of yttrium in the samarium fraction when 4.41 mg of yttrium and 7.12 mg of samarium were present originally. Control of the pH during the column operations is essential because the peak positions are very sensitive to change in pH. The relevant distribution coefficients, elution curves of pairs of elements and results for the analysis of synthetic mixtures are presented. Also included is a method for separating yttrium and the lanthanides from HEDTA and sodium and ammonium ions. 相似文献
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pISep is a major new advance in low ionic strength ion exchange chromatography. It enables the formation of externally controlled pH gradients over the very broad pH range from 2 to 12. The gradients can be generated on either cationic or anionic exchangers over arbitrary pH ranges wherein the stationary phases remain totally charged. Associated pISep software makes possible the calculation of either linear, nonlinear or combined, multi-step, multi-slope pH gradients. These highly reproducible pH gradients, while separating proteins and glycoproteins in the order of their electrophoretic pIs, provide superior chromatographic resolution compared to salt. This paper also presents a statistical mechanical model for protein binding to ion exchange stationary phases enhancing the electrostatic interaction theory for the general dependence of retention factor k, on both salt and pH simultaneously. It is shown that the retention factors computed from short time isocratic salt elution data of a model protein can be used to accurately predict its salt elution concentration in varying slope salt elution gradients formed at varying isocratic pH as well as the pH at which it will be eluted from an anionic exchange column by a pISep pH gradient in the absence of salt. 相似文献
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The chromatographic behaviour of nitrilotriacetatocomplexes of the rare earth elements (Sc, Y and lanthanides) on a reversed phase ODS column has been investigated in the presence of 1-octane-sulphonate. There is a great difference in selectivity for the ODS among the rare earth nitrilotriacetato-complexes. Concentration gradient elution with nitrilotriacetic acid (0.005-0.050M, pH 3.0) that contains 0.01M 1-octanesulphonate allows the rare earth elements to be separated from each other within 30 min at room temperature, except a Gd-Eu pair which is eluted together. Yttrium elutes at about 10 min between samarium and neodymium. Detection and quantitation of the rare earth elements can be achieved by post-column reaction with Chlorophosphonazo III in acid media at 700 nm. 相似文献
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《Spectrochimica Acta Part B: Atomic Spectroscopy》2003,58(8):1541-1552
On-line system incorporating a microcolumn of Muromac A-1 resin was used for the developing of method for preconcentration of trace elements followed by inductively coupled plasma (ICP) atomic emission spectrometry determination. A chelating type ion exchange resin has been characterized regarding the sorption and subsequent elution of 24 elements, aiming to their preconcentration from water samples of different origins. The effect of column conditioning, pH and flow rate during the preconcentration step, and the nature of the acid medium employed for desorption of the retained elements were investigated. A sample (pH 5) is pumped through the column at 3 ml min−1 and sequentially eluted directly to the ICP with 3 M HNO3/HCl mixtures. In order to remove residual matrix elements from the column after sample loading a short buffer wash was found to be necessary. The effectiveness of the matrix separation process was illustrated. The procedure was validated by analyzing several simple matrices, Standard River water sample as well as artificial seawater. Proposed method can be applied for simultaneous determination of In, Tl, Ti, Y, Cd, Co, Cu and Ni in seawater and for multielement trace analysis of river water. Recovery at 1 μg l−1 level for the determination of investigated 24 elements in pure water ranged from 93.1 to 96% except for Pd (82.2%) and Pb (88.1%). For the same concentration level for seawater analysis recovery was between 81.9 and 95.6% except for Hg (38.2%). 相似文献
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采用吸附树脂Amberlite XAD-4从水溶液中富集痕量元素 总被引:1,自引:0,他引:1
本文采用短吸附柱(10×60mm,充填高度24mm)研究了非离子性吸附树脂AmberliteXAD-4从水溶液中对16种金属元素的氢氧化物,二硫代氨基甲酸衍生物的配合物和二甲酚橙配合物的吸附行为。难溶金属化合物在树脂上的吸附率与溶液pH值的关系与采用活性碳作吸附剂的情况十分相似。而含有亲水基团的二甲酚橙螯合物不被树脂吸附。对吸附于树脂上的痕量元素的洗脱以及采用火焰原子吸收光谱法测定丙酮富集液中的金属元素问题也进行了讨论。 相似文献
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《Spectrochimica Acta Part B: Atomic Spectroscopy》2005,60(1):125-129
A new method has been developed for the determination of trace rare earth elements (REEs) in water samples based on preconcentration with a microcolumn packed with multiwalled carbon nanotubes (MWNTs) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimum experimental parameters for preconcentration of REEs, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been investigated. The studied REEs ions can be quantitatively retained by MWNTs when the pH exceed 3.0, and then eluted completely with 1.0 mol L−1 HNO3. The detection limits of this method for REEs was between 3 and 57 ng L−1, and the relative standard deviations (RSDs) for the determination of REEs at 10 ng mL−1 level were found to be less than 6% when processing 100 mL sample solution. The method was validated using a certified reference material, and has been successfully applied for the determination of trace rare earth elements in lake water and synthetic seawater with satisfactory results. 相似文献