Determination of 237Np and Pu isotopes in large soil samples by inductively coupled plasma mass spectrometry

A new method for the determination of (237)Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of (237)Np and Pu isotopes by ICP-MS. (238)U can interfere with (239)Pu measurement by ICP-MS as (238)UH(+) mass overlap and (237)Np via (238)U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1×10(6). Alpha spectrometry can also be applied so that the shorter-lived (238)Pu isotope can be measured successfully. (239) Pu, (242)Pu and (237)Np were measured by ICP-MS, while (236)Pu and (238)Pu were measured by alpha spectrometry.     

磷酸三丁酯萃淋树脂色层分离电感耦合等离子体质谱法测定富稀土样中微量铀和钍

研究了磷酸三丁酯萃淋树脂色层分离,电感耦合等离子体质谱法测定富稀土样中微量铀、钍的方法。样品经消解后,以磷酸三丁酯萃淋树脂为固定相、8 mol/L硝酸为流动相过柱分离,样品中的大部分稀土元素随流动相流出,而铀和钍则被固定相吸附,用去离子水洗脱后,再用电感耦合等离子体质谱仪测定。铀、钍的检出限分别为0.06,0.16μg/L,测定结果的相对标准偏差均小于10%(n=5),加标回收率为98%~105%。对稀土矿石标准物质进行测定,测定值与推荐值相符。该法操作简便,测定结果可靠,适于富稀土样中微量铀、钍的测定。     

应用离子色谱离线螯合及ICP-MS测定海水中多种痕量元素

简要介绍如何构建和运用离子色谱离线螯合系统结合ICP-MS方法分析海水中的痕量元素.     

Group separation of trace rare-earth elements by countercurrent chromatography for their determination in high-purity calcium chloride

A method has been developed for the separation of the entire group of rare-earth elements from high-purity calcium chloride by countercurrent chromatography, and subsequent determination of the elements by ICP-MS. A solution of diphenyl[dibutylcarbamoylmethyl]phosphine oxide in chloroform (0.5 mol L(-1)) has been chosen as reagent for the extraction and preconcentration of trace rare-earth elements from aqueous 5% CaCl2 solution, 3 mol L(-1) in HNO3 and 0.1 mol L(-1) in HClO4. The analytes are back-extracted into a small volume of water and the aqueous eluate is subjected to ICP-MS measurements. The performance characteristics of the procedure developed have been checked by use of the standard addition technique and a real CaCl2 sample (Merck product) has been analyzed. The results obtained demonstrate the applicability of countercurrent chromatography to the determination of ultratrace elements.     

Rapid determination of 237Np and Pu isotopes in water by inductively-coupled plasma mass spectrometry and alpha spectrometry

A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of ²³⁷Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry. ²³⁸U can interfere with ²³⁹Pu measurement by ICP-MS as ²³⁸UH⁺ mass overlap and ²³⁷Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4?C6 h, and can also be used for emergency response. ²³⁹Pu, ²⁴²Pu and ²³⁷Np were measured by ICP-MS, while ²³⁶Pu, ²³⁸Pu, and ²³⁹Pu were measured by alpha spectrometry.     

Flow-injection chemiluminescence determination of chlorinated isocyanuric acids

A rapid and sensitive flow-injection chemiluminescence method is described for the determination of dichloro- and trichloroisocyanuric acids based on the chemiluminescence produced during their reaction with luminol in alkaline medium. The effects of analytical and flow-injection variables on these chemiluminescence systems and determination of both oxidants are discussed. The optimized method yielded 3sigma detection limits of 8x10(-8) and 5x10(-8) mol L(-1) for the sodium dichloroisocyanurate and trichloroisocyanuric acid, respectively. The optimum conditions were found to be as follows: NaOH, 1x10(-1) mol L(-1); luminol, 5x10(-3) mol L(-1); KI, 2x10(-3) mol L(-1) and flow rate, 3.5 mL min(-1).     

Determination of (236)U and transuranium elements in depleted uranium ammunition by alpha-spectrometry and ICP-MS

It is well known that ammunition containing depleted uranium (DU) was used by NATO during the Balkan conflict. To evaluate the origin of DU (the enrichment of natural uranium or the reprocessing of spent nuclear fuel) it is necessary to directly detect the presence of activation products ((236)U, (239)Pu, (240)Pu, (241)Am, and (237)Np) in the ammunition. In this work the analysis of actinides by alpha-spectrometry was compared with that by inductively coupled plasma mass spectrometry (ICP-MS) after selective separation of ultratraces of transuranium elements from the uranium matrix. (242)Pu and (243)Am were added to calculate the chemical yield. Plutonium was separated from uranium by extraction chromatography, using tri- n-octylamine (TNOA), with a decontamination factor higher than 10(6); after elution plutonium was determined by ICP-MS ((239)Pu and (240)Pu) and alpha-spectrometry ((239+240)Pu) after electroplating. The concentration of Pu in two DU penetrator samples was 7 x 10(-12) g g(-1) and 2 x 10(-11) g g(-1). The (240)Pu/(239)Pu isotope ratio in one penetrator sample (0.12+/-0.04) was significantly lower than the (240)Pu/(239)Pu ratios found in two soil samples from Kosovo (0.35+/-0.10 and 0.27+/-0.07). (241)Am was separated by extraction chromatography, using di(2-ethylhexyl)phosphoric acid (HDEHP), with a decontamination factor as high as 10(7). The concentration of (241)Am in the penetrator samples was 2.7 x 10(-14) g g(-1) and <9.4 x 10(-15) g g(-1). In addition (237)Np was detected at ultratrace levels. In general, ICP-MS and alpha-spectrometry results were in good agreement.The presence of anthropogenic radionuclides ((236)U, (239)Pu,(240)Pu, (241)Am, and (237)Np) in the penetrators indicates that at least part of the uranium originated from the reprocessing of nuclear fuel. Because the concentrations of radionuclides are very low, their radiotoxicological effect is negligible.     

Application of high-surface-area ZrO2 in preconcentration and determination of 18 elements by on-line flow injection with inductively coupled plasma atomic emission spectrometry

A flow-injection analysis (FIA) system incorporating a micro-column of ZrO2 has been used for the development of an on-line multi-element method for the simultaneous preconcentration and determination of Al, Bi, Cd, Co, Cr, Cu, Fe, Ga, In, Mn, Mo, Ni, Pb, Tl, V, Sb, Sn, and Zn by inductively coupled plasma atomic emission spectrometry (ICP-AES). The conditions for quantitative and reproducible preconcentration, elution, and subsequent on-line ICP-AES determination were established. A sample (pH 8) is pumped through the column at 3 mL min(-1) and sequentially eluted directly into the ICP-AES with 3 mol L(-1) HNO3. With a sample volume of 100 mL and an elution volume of 1 mL signal enhancement 100 times better than for conventional continuous aspirating systems was obtained for the elements studied. The reproducibility (RSD %) of the method at the 10 ng mL(-1) level in the eluate is acceptable - less than 8% for five replicates. Recoveries between 95.4% and 99.9% were obtained for the elements analysed. ZrO2, with a specific surface area of 57 m2 g(-1) and a capacity of approximately 5 mg g(-1) for the elements studied, was synthesized by hydrolysis of ZrCl4. The preconcentration system was evaluated for several simple synthetic matrices, standard water samples and synthetic seawater. The effect of foreign ions on the efficiency of preconcentration of the elements studied was investigated. The application of a micro-column filled with high-surface-area ZrO2 and flow injection inductively coupled plasma atomic emission spectrometry enables preconcentration and simultaneous determination of 18 elements at low concentrations (ng L(-1)) in different water samples.     

ICP–OES法测定八氧化三铀中杂质元素钨

以ICP–OES法测定八氧化三铀中杂质元素钨。采用浓HNO3–浓HCl、浓HNO–HF、3 mol/L HNO3三步酸溶方案,利用CL–TBP萃淋树脂将铀基体分离,淋洗液基质为3 mol/L HNO3,淋洗液流速为1 mL/min。弃去最初2 mL死体积淋洗液后接收10 mL,分离回收率平均值为95.93%,线性方程为y=539.71x+16.6,相关系数r2=0.999 7,4水平样品测定结果的相对标准偏差为0.39%~3.12%(n=6)。用该方法对标准物质进行测定,测定结果在参考值范围内。     

Molecularly imprinted on-line solid-phase extraction combined with flow-injection chemiluminescence for the determination of tetracycline

A molecularly imprinted polymer solid phase extraction (MISPE) method combined with flow-injection chemiluminescence (FI-CL) for the determination of residual tetracycline (TC) in fish samples is presented. The molecularly imprinted polymer (MIP) of TC was synthesized and particles of this MIP were packed into a polytetrafluoroethylene (PTFE) tube, which was connected into the sampling loop of an eight-way injection valve and served as the MISPE column for on-line selective adsorption of TC. The eluent (CH3CN : HNO3 (0.01 mol L(-1)) = 4 ratio 1, v ratio v) was used for extracting the adsorbed TC, which could be detected by its good enhancing effect on the CL reaction between Ce(iv) and rhodamine B. The CL intensity is linear to TC concentration in the range from 4 x 10(-9) to 4 x 10(-7) g mL(-1). The detection limit is 1 x 10(-9) g mL(-1) (3 sigma) and the relative standard deviation is 2.4% (n = 9). The conditions of preconcentration, extraction and CL reaction were carefully studied. The selectivity experiment shows that the selectivity and sensitivity of the CL method could be improved greatly when MIP was used as a recognition material in SPE. However, the MISPE column interacted indiscriminately with oxytetracycline (OTC) with a 49 +/- 2% binding. An intermediate differential pulsed elution (DPE) step using 3% acetic acid as eluent was employed to remove OTC and other interfering substances. The proposed MISPE-CL method has been applied successfully to the determination of TC in fish samples. At the same time, the binding characteristics of the polymer to tetracycline were evaluated by batch and dynamic methods.     

高效液相色谱法测定吲哚美辛控释胶囊的血药浓度和生物利用度

采用ＯＤＳ柱,甲醇－稀磷酸溶液（７６２４）为流动相,２６０ｎｍ为检测波长,建立了测定血浆中吲哚美辛浓度的高效液相色谱法,并测定了吲哚美辛控释胶囊炎痛康的血药浓度。结果表明,血浆中吲哚美辛浓度在０．１２５～５．０ｍｇ／Ｌ范围内线性关系良好（ｒ＝０．９９９６）,检测限６２．５μｇ／Ｌ（Ｓ／Ｎ＝３１）,平均回收率为１００．４％,日内和日间ＲＳＤ均小于５％。１１位受试者单剂量口服炎痛康后的相对生物利用度为１０２．３８％。     

Neptunium determination by inductively coupled plasma mass spectrometry (ICP-MS)

The determination of neptunium-237 (²³⁷Np) traditionally has been performed by alpha spectrometry or neutron activation analysis. These methods are labor intensive and require several days for completion. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a possible alternative for²³⁷Np determinations. This paper describes the analytical method developed for samples that have significant levels of uranium present. The lower reporting limits achievable by ICP-MS are competitive with the counting methods, but the real advantage for this laboratory lies in the lower cost and faster turnaround time provided by ICP-MS.     

贵金属元素电化学分析研究VI.黄原酸钠纤维素酯富集,分离锇,钌样品中的银及其阳极溶出伏安法测定

Cellulose xanthate cotton was used for enrichment and separation of Ag from bulk Os and Ru from 0.65 mol HNO3/L solution The adsorbed Ag was eluted with 8-10 4M HNO3. Submicrogram quantity of Ag can be enriched and separated from the cotton with a recovery of 98%. Trace Ag was determine on glass carbon electrode by anodic stripping voltammetry in the electrolytic system of 0.1 mol KSCN/L-0.2 mol HNO3/L-2.5 mol CyDTA/L. The linear range between the concentration and the peak current of Ag is 10-11 to 10-7 g/mL. The detection limit reaches 10 parts per trillion for 10 min electrolysis. The relative standard deviation is 4.2% for Os sample with 6 replicate detns. The results agree with those obtained by atomic absorption spectrometry.     

Speciation of Cr(III) and Cr(VI) in potable waters by using activated neutral alumina as collector and ET-AAS for determination

The speciation of Cr(III) and Cr(VI) has been performed by using activated neutral alumina as adsorbent. Both species were quantitatively adsorbed on a small column filled with neutral alumina. The adsorbed Cr(III) was eluted with 4 mol L(-1) HNO(3) and Cr(VI) with 1.0 mol L(-1) ammonia solution. Recoveries of Cr(III) and Cr(VI) were 99% and 100%, respectively. Using ET-AAS for Cr determination the limit of detection in the sample was 0.01 microg L(-1). The combined procedure is fast and sensitive. It can be applied for routine analysis of water samples at sub-microg L(-1) levels with a relative standard deviation (RSD) of 2-10% (three determinations).     

Sensitive redox speciation of neptunium by CE–ICP–MS

Capillary electrophoresis (CE) was used to separate the neptunium oxidation states Np(IV) and Np(V), which are the only oxidation states of Np that are stable under environmental conditions. The CE setup was coupled to an inductively coupled plasma mass spectrometer (Agilent 7500ce) using a Mira Mist CE nebulizer and a Scott-type spray chamber. The combination of the separation capacity of CE with the detection sensitivity of inductively coupled plasma mass spectrometry (ICP-MS) allows identification and quantification of Np(IV) and Np(V) at the trace levels expected in the far field of a nuclear waste repository. Limits of detection of 1?×?10^-9 and 5?×?10^-10 mol L^-1 for Np(IV) and Np(V), respectively, were achieved, with a linear range from 10^-9 to 10^-6 mol L^-1. The method was applied to study the redox speciation of the Np remaining in solution after interaction of 5?×?10^-7 mol L^-1 Np(V) with Opalinus Clay. Under mildly oxidizing conditions, a Np sorption of 31% was found, with all the Np remaining in solution being Np(V). A second sorption experiment performed in the presence of Fe²⁺ led to complete sorption of the Np onto the clay. After desorption with HClO₄, a mixture of Np(IV) and Np(V) was found in solution by CE–ICP–MS, indicating that some of the sorbed Np had been reduced to Np(IV) by Fe²⁺.     

球状苯基纤维素填料在低压疏水制备色谱分离天然菠萝酶中的应用

通过将苯环接技于球状大孔纤维素白球的方法,得到一类以大孔球状纤维素为基质的大型流水性工业色谱填料,并研究了其分离天然菠萝酶的色谱条件。色谱代化条件为：流动相100mL,含1．5mol／L（NH4）2SO4,0.1mol／LNaAc－HAc（pH4．8）缓冲液;洗脱液3OmL．含67mmol／LNaOH,50mmol／LNa2CO3－NaHCO3缓冲液（pH10.28）;流速1．0mL／min。在此条件下使用该填料10mL分离提纯天然菠萝酶,可得到大于120％的活性回收率。     

微波消解-ICP/MS测定烤烟中微量元素含量

以3 mL HNO3和2 mL H2O2的混合消解液对烟草样品进行微波消解,采用电感耦合等离子体质谱测定了烤烟中的Mn、Zn、Cu、Se、N i、Co、Cr、As、Cd、Pb 10种微量元素的含量.结果表明：方法的检出限均低于0.02μg/g,各元素测定的RSD（n=5）均小于3%,样品加标回收率为97.35%-101.30%.方法消耗试剂少,快速准确,适合烟草中多种微量元素的同时测定.     

Simultaneous determination of Cd, Cu, Mn, Ni, Pb and Zn in nail samples by inductively coupled plasma mass spectrometry (ICP-MS) after tetramethylammonium hydroxide solubilization at room temperature: comparison with ETAAS

A simple method is described for the determination of Cd, Cu, Mn, Ni, Pb and Zn in nails by using inductively coupled plasma mass spectrometry (ICP-MS) or electrothermal atomic absorption spectrometry (ETAAS). Prior to analysis, 10-20 mg of nail samples were accurately weighed into (15 mL) conical tubes. Then, 1 mL of 25% (w/v) tetramethylammonium hydroxide (TMAH) solution was added to the samples, incubated at room temperature overnight and then further diluted to 10 mL with 1% (v/v) HNO(3). After that, samples were directly analyzed. Rhodium was used as internal standard for ICP-MS analysis. Method detection limits (3 s, n=20) were 0.1, 3.0, 1.0, 4.5, 1.5, 5.0 ng g(-1) for Cd, Cu, Mn, Ni, Pb and Zn, respectively for ICP-MS, and 24, 26, 30, 143, 130 and 1000 ng g(-1), respectively for ETAAS. The key issue addressed here is the elimination of the acid digestion prior to analysis. Moreover, with the use of the proposed method there is a considerable improvement in the sample throughput comparing to the traditional methods using microwave-assisted acid sample digestion prior to analysis. For validation purposes, six ordinary nail samples were solubilized and then directly analyzed by ICP-MS and ETAAS, with no statistical difference between the two techniques at 95% level on applying the t-test.     

Microwave digestion methods for the determination of trace elements in brain and liver samples by inductively coupled plasma mass spectrometry

Two microwave digestion systems (open-focused and closed-pressurized) were tested for the mineralization of human brain and bovine liver (NIST SRM 1577a) as dissolution steps prior to the determination of 16 trace elements (Bi, Cd, Co, Cs, Cu, Fe, Hg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn) by inductively coupled plasma mass spectrometry (ICP-MS). Digestion parameters (mass of sample, digestion mixture, and power/time steps) were optimized using temperature and pressure sensors. Digestions with the open-focused microwave system require larger volumes of conc. HNO(3) and 30% H(2)O(2) than digestions with the closed-pressurized system. Both systems produce correct results for the bovine liver samples. The concentrations obtained for the digests of the open-focused system tend to be less precise than the concentrations from the "closed-pressurized" digests. Because the "open-focused" digests must be diluted to 50 mL to bring the acid concentration to 0.7-2.0 mol/L required by the ICP-MS (closed-pressurized digests need to be diluted to only 20 mL), the detection limits for the system with the open-focused digestion are higher than for the system with the closed-pressurized digestor. The open-focused digestor cannot handle more than 150 mg brain tissue, whereas the closed-pressurized system can mineralize 470 mg. The latter method gave better results with brain tissue than the open-focused system. The preparation of brain tissue as reference material for the determination of trace elements in brain samples is described.     

Optimization of extraction chromatography separations of trace levels of actinides with ICP-MS detection

The separation of trace level actinides has been evaluated on extraction chromatography columns. Detection of the actinides was achieved through the use of an inductively coupled plasma MS (ICP-MS). The columns that we tested were prepared from a commercial TRU resin. The separation of the actinides was optimized for several parameters including particle size, column length, packing pressure, and eluent flow rate. We also examined the possibility of reducing or eliminating oxalic acid in the eluents in order to improve the performance of the mass spectrometer. We were able to separate a mixture of five actinides ((232)Th,( 238)U,( 237)Np, (239)Pu,( 243)Am) in less than 4 min. This work has application to rapid bioassay as well as for automated separations of actinide materials.