The automated photometric determination of total fluorine in mineral exploration

An analytical method previously applied to the determination of fluorine in rocks and minerals would seem to be ideal for exploration samples such as soils, stream sediments and vegetation. The determination which utilises the Zr-xylenol orange complex is performed on acidified leachates following sodium carbonate fusion. This digestion technique is rapid, simple and amenable to batch sample processing. The method, which is applicable to samples containing from about 10 ppm to over 3% fluorine, is essentially interference free.     

2—（5—溴—2—吡啶偶氮）—5—二甲氨基苯胺与铂显色反应的研究及应用

研究了显色剂２ （５ 溴 ２ 吡啶偶氮） ５ 二甲氨基苯胺（５ Ｂｒ ＰＡＤＭＡ）与Ｐｔ（Ⅱ）的显色反应。结果表明,在乙醇存在下,１０～３２ｍｏｌ／ＬＨ３ＰＯ４介质中,试剂与Ｐｔ（Ⅱ）１５ｍｉｎ即形成稳定的紫蓝色配合物,并至少稳定２４ｈ。该配合物的最大吸收波长位于６２８ｎｍ处,表观摩尔吸光系数为８７３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１,其组成为ｎＰｔ（Ⅱ）∶ｎ５ Ｂｒ ＰＡＤＭＡ＝１∶１,Ｐｔ（Ⅱ）的质量浓度在０～１０ｍｇ／Ｌ符合比尔定律。所拟方法用于二次合金管理样及催化剂中铂的直接测定,结果与推荐     

Spectrophotometric Determination of Vanadium in Carbonaceous Shales (Stone Coal Ores) Using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

A selective and sensitive spectrophotometric method has been developed for determining the total amount of vanadium in carbonaceous shales (stone coal ores). The method is based on the reaction of vanadium(V) with the chromophore reagent 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of hydrogen peroxide. In a 0.072 mol l⁻¹ sulfuric acid medium, 5-Br-PADAP reacts with vanadium(V) to form a red-violet complex with a maximum absorption peak at 596 nm with an apparent molar absorption coefficient of the complex of 8.45 × 10⁴ l mol⁻¹ cm⁻¹. Beer's law was obeyed in the range 0–25 μg vanadium in 25 ml of solution, with a correlation coefficient of 0.9995. Interferences due to various non-target ions were also investigated and high quantities of other common inorganic ions were tolerable. The method involved the dissolution of the ore sample by Na₂O₂ fusion, followed by filtering of the alkali solution after which Fe(III), Cu(II), Ni(II) and Co(II) etc. were effectively separated from the solution by precipitation in a NaOH solution. Selectivity was increased with the use of EDTA as a masking agent. The vanadium in ore samples was determined with a relative deviation (RSD) between 0.20 and 0.76%, and has been successfully applied to the determination of vanadium-bearing stone coal ores. The results indicated that the accuracy of 5-Br-PADAP spectrophotometry is comparable with the ICP-AES method. The characteristics of the method, i.e., simplicity, selectivity, sensitivity and rapid calibration, make it specially suitable for routine analysis.     

Alpha-spectrometric determination of uranium and thorium in geological samples

Alpha-spectrometric technique is described as an independent method for determining micro-contents of U²³⁸ and Th²³². It is based on the comparison of alpha spectral activity of U²³⁸ and Th²³² in geological samples with that contributed by the U²³²·Th²²⁸ spike of known concentration. The experiment procedure consists of dissolving fine powdered samples with acid and adding a given amount of U²³²-Th²²⁸ spike. Uranium and thorium are then separated by ion exchange. After purification, each aliquot is mounted onto a separate stainless steel disk for measurement by alpha spectrometer, which consists essentially of a silicon surface barrier detector and a low noise amplification system connected to a multi-channel analyzer. After corrections for the background, tail and other factors, the desired U²³² and Th²³² concentrations can be calculated. The data obtained by the alpha-spectrometric method using U²³²-Th²²⁸ spike are compared with colorimetric determinations. Excellent agreement is obtained between the two sets of results. The coefficients of correlation are about 0.98 for U²³⁸ and 0.97 for Th²³². The accuracy of uranium and thorium analyses by this method depends primarily upon the counting statistics of U²³², U²³⁸ and Th²²⁸ and, to a certain extent, upon the calibration of U²³²-Th²²⁸ spike. Errors in uranium and thorium concentrations obtained by this method are generally within 2 to 5%.     

X-ray flurorescene (XRF) determination of trace rare-earth elements in geological samples using ion-exchange-resin membrane technique

Rare-earth elements in samples of geological interest were separated from other elements and concentrated onto ion-exchange membrane through ion-exchange procedures. The membrane was then used to determine the REE by X-ray fluorescence spectrography. In comparison with the traditional “thick-specimen” approach, the requirement of sample (REE oxides) in this method was reduced from 10 to 1 mg. Variable-internal-standard-quantification method was adopted to determine the relative concentrations of REE collected on the membrane. The area density of the sample was controlled at about 0.0003 g/cm², so that the matrix effect could be eliminated to a satisfactory extent. Interference calibration between the spectro-lines and the background determination was also improved, with the detection limit reaching 2.5×10^?6g.     

地质样品中铂族元素的分析测定方法

文中阐述并归纳了近年地质样品中铂族元素的分离、富集及测试方法方面的最新进展。铂族元素本身的超痕量性,要求实验过程中对空白值的控制,干扰元素的扣除和检测限的降低更为严格,同时要克服块金效应。文中对消解过程中常用的火试金法、酸溶、碱熔方法和卡洛斯管法(Carius tube),分离富集过程中的Te共沉淀和离子交换法,测试手段中的原子光谱法、中子活化法和等离子质谱法等方法的最新进展进行了总结。由于复杂的地质样品中PGE的浓度范围不一、赋存形式多样,要求在具体样品分析过程中灵活地搭配使用各种分离富集和检测方法,结合笔者所在实验室在实验过程中发现的问题,对各种不同类型地质样品中铂族元素的分离富集、样品处理及测定方法也进行了总结。     

对氨基二甲基苯胺比色法测定的地下水中硫化物 不确定度的评定

采用不确定度连续传递模型对对氨基二甲基苯胺分光光度法测定的地下水中硫化物的不确定度进行了评定,在标准曲线拟合这一关键步骤上采用双误差曲线拟合,并与最小二乘法的拟合结果进行比较。结果表明,对于含较高浓度硫化物的水样,由双误差拟合出来的结果比最小二乘法拟合的结果更为准确。在采用双误差曲线拟合对实际样品进行定量时,应选择合适浓度范围内的标准曲线,使测定浓度落在标准曲线的较高浓度部分,使结果更为准确、合理。     

对氨基二甲基苯胺比色法测定的地下水中硫化物不确定度的评定

采用不确定度连续传递模型对对氨基二甲基苯胺分光光度法测定的地下水中硫化物的不确定度进行了评定,在标准曲线拟合这一关键步骤上采用双误差曲线拟合,并与最小二乘法的拟合结果进行比较。结果表明,对于含较高浓度硫化物的水样,由双误差拟合出来的结果比最小二乘法拟合的结果更为准确。在采用双误差曲线拟合对实际样品进行定量时,应选择合适浓度范围内的标准曲线,使测定浓度落在标准曲线的较高浓度部分,使结果更为准确、合理。     

Laser ablation multicollector ICPMS determination of δ11B in geological samples

A method for the in situ single spot δ¹¹B characterisation of geological materials with laser ablation multicollector ICP mass spectrometry (LA-MC-ICPMS) has been developed. The mass spectrometer was equipped with both Faradays and multiple ion counters. Four samples with different B contents (12–31,400 ppm) and isotopic compositions (δ¹¹B are between −8.71 and +13.6‰) were analysed. Samples include the B4 tourmaline and 3 MPI-DING glasses (StHs6/80-G, GOR132-G and GOR128-G).All sources of B isotopic fractionation during the analysis (mass bias, laser-induced isotopic fractionation and detector efficiency drift) have been evaluated and quantified. Instrumental mass bias is the major source of fractionation, altering the original isotopic ratio up to 13%. Fractionation related to laser sampling and transport to the ICP was found to be very low (less than 0.0015% s⁻¹). Fractionation effects due to drift in ion counter efficiencies were found to be significant. Nevertheless, the “standard-sample-standard” bracketing approach could be used to correct for the above fractionation effects using NIST SRM 610 as external standard.With spot sizes of 60–80 μm in diameter, geologically meaningful results can be achieved on samples containing at least 10 ppm B, i.e., results with precisions that can discriminate between the different reservoirs on Earth. Data obtained with Faraday detectors on NIST SRM 610 and B4 tourmaline show high precision (down to 0.04‰, 1σ) and accuracy. Boron isotope ratios measured in the glass samples using multiple ion counting show significantly higher standard deviations (up to 2.5‰, 1σ), but they are very close to the values that can be expected from counting statistics. No significant variations with spot size or B contents were observed. Most of the values are within 1σ level of the reference values.The developed method was applied to a series of ashes from Mt. Etna erupted in 1995 having B contents between 14 and 20 ppm. The B isotope compositions of the ashes are between −4.8 and −10.7‰, with a weighted average value of −8.0 ± 1.9‰ (1σ).     

离子色谱法测定水样中S2-、SO2-3、SO2-4、S2O2-3

该种方法利用离子色谱仪的电导检测器与电化学检测器串联,十几分钟即可连续完成水中S2-、SO2-3、SO2-4、S2O2-3的测定,方法具有快速、高效、方便、灵敏、选择性好等特点.方法的检出限分别为S2-12.5μg/L;SO2-3 22.4μg/L;SO2-4 5.0μg/L;S2O2-3 5.0μg/L.相对标准偏差在1.5%～6.9%之间,能够满足水中S2-、SO2-3、SO2-4、S2O2-3四种阴离子分析测试的需要.     

1-(2-羟基-3,5-二硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯与铜的显色反应及应用

研究了新合成的１ － （２ － 羟基－ ３ ,５ － 二硝基苯基） － ３ － ［ ４ － （ 苯基偶氮） 苯基］ － 三氮烯（ ＨＤＮＰＡＰＴ） 试剂与铜的显色反应。在乳化剂ＯＰ存在下,ｐＨ１１ ．０ 的Ｎａ２Ｂ４ Ｏ７ － ＮａＯＨ 介质中,铜与ＨＤＮＰＡＰＴ 形成稳定的红色配合物,其组成比为１∶２ ,λｍ ａｘ ＝ ５４０ ｎ ｍ ,表观摩尔吸光系数ε５４０ ＝ １ ．７３ ×１０５ Ｌ·ｍｏｌ－ １·ｃｍ － １ ,铜的质量浓度在０ ～３６０ μｇ／ Ｌ符合比尔定律。方法应用于大米和面粉中微量铜的测定,结果与铜试剂法相符,５ 次测定的ＲＳＤ＜ ３ ％ 。     

电感耦合等离子体发射光谱法在地质样品分析中的应用进展

概述了电感耦合等离子体发射光谱法( ICP?AES)在测定技术方面的进展,强调该仪器测定条件对测定元素曝光强度的影响以及对测定中各元素分析谱线的选择和干扰元素的影响;介绍了ICP?AES测定技术在地质样品分析中的应用。测定土壤、岩石、水洗沉积物、矿石样品、植物样品和水样样品中的元素时,应根据样品性质的不同和测定元素的不同而采用不同的消解体系(酸溶法、碱熔法和微波消解法)。在测定土壤、岩石和水洗沉积物样品时,比较了不同消解体系各自的特点,同时也对比了采用不同消解体系时各元素的方法检出限,结果显示,酸溶法的检出限要明显优于碱熔法;在测定矿石样品时,对比了各元素在不同消解体系中的测定精密度,结果显示测定精密度均较好;总结了测定常见植物样品中无机元素的典型前处理方法以及ICP?AES测定水样中的元素全量和元素不同价态含量的方法。最后,对ICP?AES测定技术在地质行业的应用作了展望,相信ICP?AES还将在地质样品的分析中继续发挥作用。     

Sigioite : The oxidation mechanism in [M 2 3 + (PO4)2(OH)2(H2O)2]2 - structures

Summary The crystal structure of sigloite, Fe³ [(H₂O)₃OH] [Al₂(PO₄)₂(OH)₂(H₂O)₂]- 2 H₂O, triclinic, a 5.190 (2), b 10.419 (4), c 7.033 (3) Å, 105.00 (3), 111.31(3), 70.87 (3)°, V 330.5 (2) Å3, Z = 1, space group P , has been refined to anR index of 5.3% using 1713 observed (I > 2.5 1) reflections collected with graphite-monochromated MoK X-rays. Sigloite is isostructural with the laueite-group minerals. Corner-linked [A1₅] chains (: unspecified ligand) are cross-linked by (PO₄) tetrahedra to form a mixed corner-linked tetrahedral-octahedral sheet of composition [A1₂(PO₄)₂(OH)₂(H₂O)₂]²-. These sheets are linked by (Fe³⁺O₂(OH, H₂O)₄) octahedra and two (H₂O) groups that participate in a hydrogen-bonding network. Sigloite is the oxidized equivalent of paravauxite, Fe²⁺(H₂O)4[Al₂(PO₄)₂(OH)₂(H₂O)₂]-² H₂O, and detailed comparison of the two structures shows that the oxidation mechanism involves loss of hydrogen from one of the (H₂O) groups coordinating the Fe³⁺, and positional disorder of both the Fe³⁺ and (OH) and (H₂O) ligands.

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Siggloit: Der Oxidationsmechanismus in (M ₂ ³ ₊ (PO₄)₂(OH)₂(H2O)₂]²- Strukturen

Zusammenfassung Die Kristallstruktur von Sigloit, Fe³⁺ [(H₂O)₃OH] [Al₂(PO₄)₂(OH)₂(H₂O)₂].2 H₂O, triklin, a 5,190 (2), b 10,419 (4), c 7,033 (3) Å, 105,00 (3), 111,31 (3), 70,87 (3)°, V 330,5 (2) ų,Z = 1, Raumgruppe P , wurdefür 1713 beobachtete Reflexe (I > 2,5 I), die mit MoKa-Röntgenstrahlung (Graphit-Monochromator) gesammelt wurden, auf einen R-Wert von 5,3% verfeinert. Sigloit ist isotyp mit den Mineralen deer Laueit-Gruppe. Über Ecken verknüpfte [A1₅]-Ketten (: nicht spezifizierter Ligand) werden über (P0₄)-Tetraeder zu ebenfalls über Ecken verknüpfte Tetraeder-OktaederSchichten der Zusammensetzung [A1₂(PO₄)₂(OH)₂(H₂O)₂]²- verbunden. Diese Schichten werden über (Fe³⁺O₂(OH, H2O)₄)-Oktaeder und zwei (H₂O)-Gruppen, die amWasserstoffbrücken-Netzwerk beteiligt sind, verbunden. Sigloit ist das oxidierte Analogon zu Paravauxit, Fe²⁺(H₂O)₄[A1₂(PO₄)₂(OH)₂(H₂O)₂] - 2 H₂O; ein detaillierter Vergleich dieser beiden Strukturen zeigt, daß der Oxidationsmechanismus sowohl den Verlust eines Wasserstoffatoms (H₂O)-Gruppe, welche ein Fe³⁺-Atom koordiniert, als auch eine Fehlordnung der Punktlagen von Fe³⁺ und von den (OH) und (H₂O) Liganden bedingt.

     

Determination of hydrogen content in geological samples using elastic recoil detection analysis (ERDA)

The present study illustrates the interest of using the elastic recoil detection analysis (ERDA) method to characterize any geological sample matrix with respect to hydrogen. ERDA is combined with Rutherford back scattering (RBS) and particle induced X-ray emission (PIXE), allowing the simultaneous characterization of the matrix with respect to major and trace elements (Z > 15). Analyses are performed by mapping of a 4 × 16 μm² incident beam of ⁴He⁺ on large areas (50 × 200 μm²). The method is almost not destructive and requires no calibration with respect to well known hydrous samples. Hydrous and nominally anhydrous phases in contact with each other in the same sample may both be characterized. The depth of the analyses is limited to several μm beneath the surface, allowing tiny samples to be investigated, provided their sizes are larger than the incident beam. Our setup has been improved in order to allow H determination on a micrometric scale with a 5-15% relative uncertainty and a detection limit of 94 wt ppm H₂O. We present multi-elemental mappings on a large panel of samples: (1) natural and analogue synthetic glasses from Stromboli volcano (0.44-4.59 wt% H₂O), natural rhyolitic glasses (1466-1616 wt ppm H₂O); (2) magmatic rhyolitic melt inclusions from Guadeloupe Island (4.37-5.47 wt% H₂O) and their quartz host crystal (2020 ± 230 wt ppm H₂O); (3) nominally anhydrous natural (82-260 wt ppm H₂O) and experimentally hydrated (240-790 wt ppm H₂O) olivines; natural clinopyroxenes (159-716 wt ppm H₂O); natural orthopyroxenes (201-452 wt ppm H₂O); a natural garnet (90 wt ppm H₂O). Results show that ERDA is a strong and accurate reference method that can be used to characterize geological sample from various matrix compositions from high to low water contents. It can be used to calibrate other methods of microanalysis such as Fourier Transform Infrared Spectroscopy (FTIR) or secondary ion mass spectrometry (SIMS).     

用滤纸负载固相反射散射分光光度法测定银

探讨一种新的固相分光光度法——固相反射散射分光光度法，通过滤纸对银缔合物的分离富集，研究Ag与对二苯胺基卡叉若丹宁形成的缔合物在滤纸相的反射散射吸光度(Ag)，从而测定样品中的Ag。实验结果表明，在酸性条件下，Ag(Ⅰ)与若丹宁在表面活性剂介质中形成稳定的缔合物，可以被均匀地抽滤到滤纸相表面，该缔合物最大吸收波长(λ)为590nm；Ag(Ⅰ)质量浓度在O～12μg/25mL范围内，与吸光度呈线性关系；Ag的检出限为0．05μg/mLL，相对标准偏差(RSD)为4．3％。     

1-（2，6-二溴-4-硝基苯）-3-（4-硝基苯）-三氮烯光度法测定铜

建立了用 1 - ( 2 ,6-二溴 - 4-硝基苯 ) - 3- ( 4 -硝基苯 ) -三氮烯 (DBNPNPT)分光光度法直接测定铜矿及铝合金样品中铜的方法。在表面活性剂TritonX - 1 0 0的存在下 ,pH在 9.5～ 1 1 .5的Na2 B4O7-NaOH介质中 ,DBNPNPT与Cu2 +可生成黄色络合物 ,以 5 35nm为参比波长 ,45 0nm为测定波长的双峰双波长法进行测定 ,表观摩尔吸光系数可达 1 .1 1× 1 0 5L·mol- 1 ·cm- 1 ,Cu2 +的质量浓     

1—（2—羟基—3,5—二硝基苯）—3—4（4—苯基—2—噻唑）—三氮稀的合成及其与镍的显

合成了新试剂 1 - (2 -羟基 - 3,5-二硝基苯 ) - 3- (4-苯基 - 2 -噻唑 ) -三氮烯 ,研究了在表面活性剂TritonX - 1 0 0存在下 ,它与Ni2 的显色反应。结果表明 ,在 pH 6.0～ 7.5时 ,Ni2 与该试剂形成配合物 ,其最大吸收峰位于 51 5nm处 ,摩尔吸光系数为 1 .0 8× 1 0 5 L·mol- 1 ·cm- 1 。Ni2 在 0～ 0 .4mg/L内符合比尔定律。方法已用于矿物、合金、钢样中微量镍的测定 ,结果与原子吸收法相符 ,     

Electrical resistivity imaging over natural (in situ) geological samples using physical model studies

To understand the characteristic responses of natural geological samples, viz., black granite, green marble, and graphite sheet, and to have “an a priori” knowledge of their physical property through electrical resistivity imaging, the physical model laboratory setup has been established to conduct scale model studies over targets of finite dimensions and resistivities. The present experiment involves IRIS make SYSCAL Pro-96 measuring system using 48 electrodes with 2-cm interelectrode separation in the laboratory model tank. In the present communication, we have presented the 2D cross section images using Wenner, Wenner–Schlumberger, and dipole–dipole array configurations over the resistive (granite, marble) and conductive (graphite) sheets. In the case of resistive target (black granite sheet, green marble), the combined usage of dipole–dipole and Wenner–Schlumberger arrays provided more accurate measures on target parameters, i.e., the combined usage of both the arrays is preferable in searching high-resistive targets beneath the low-resistive ones over burden. The shape of the resistive target (green marble sheet) is inappropriate when the thickness of the target is greater than one half of the minimum array separation. As the thickness of the target increases, the signatures of the target become feeble, and hence, the shape of the resistive target is not properly reflected in the corresponding tomogram. The response over graphite sheet indicates that the true parameters of the target are not reflected in the cross section, and the existence of the low-resistive (high-conductive) target in the host medium (water) deviates the resistivity of the medium. The target parameters from the cross section using dipole–dipole array are somewhat correlated with true parameters in the case of thin targets at shallow depths. In the case of the sequence of layers of gravel–marble gravel–sand gravel simulated in a small model tank in the physical model laboratory, the thickness of the high-resistive marble layer beneath the low-resistive gravel layer is enhanced conspicuously because of the significant resistivity contrast between gravel and marble.     

The importance of second order activation in the determination of trace elements in geological samples by instrumental neutron activation analysis

This paper deals with the disturbance of INAA trace element determinations in rocks by second order activation. The degree of error in the determination of Gd by Eu in rocks is checked by experiments and compared with results of computer evaluations. The consequence of the Dy-interference for the determination of Ho was also calculated. Hints to avoid these interferences are given.     

4—（2—羟基—4—硝基苯偶氮）—1—苯基—3—甲基吡唑啉酮与钍的显色反应

在pH为 2～ 3的HAc介质中 ,4 - ( 2 -羟基 - 4 -硝基苯偶氮 ) - 1 -苯基 - 3-甲基吡唑啉酮 (HNAPMP)与钍反应生成 2∶1的稳定络合物 ,λmax=540nm ,ε=4 .96× 1 0 4L·moL- 1·cm- 1,Th质量浓度在 0～ 2 .8mg/L内符合比尔定律。方法用于钍钨合金中钍的测定 ,相对标准偏差 (n =5)小于 1 % ,加标回收率为 97%～ 1 0 2 %。