bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a rapid technique for the determination of precious metals in geological materials based on an aqua regia leach
Authors: Gowing C J B , Potts P J
Published: November 2013

Analysis of aqua regia extracts have been made by both graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma mass spectrometry (ICP-MS) with a view to developing a rapid, simple, and inexpensive technique for the determination of
gold and the platinum-group elements (PGE) in exploration samples. Although selective extraction by aqua regia is expected to leave the sample matrix largely unattacked, resultant solutions still contain high levels of Fe, Ni, Cu, Zn, Mg, and As, which produce significant interferences when the
solutions are analyzed directly by GFAAS. To overcome these difficulties a simple solvent extraction procedure was investigated in which Au and the PGE are selectively complexed with triphenyl phosphine, then extracted from the aqueous phase into 1,2-dichloroethane. Results will be presented to
demonstrate residual interference effects, the optimization of the furnace heating programme for organic solutions and the recovery efficiency of the solvent extraction process. Routine direct analyses of diluted aqua regia solutions were found to be possible by ICP-MS. The procedures developed for
the correction of drift effects and the calibration against aqueous standards will be described. These procedures have been applied to: a. a wide range of reference materials, b. a series of samples that had been preanalyzed by nickel sulphide-fire assay, c. two new chromitite reference samples,
CHR-Pt+ and CHR-Bkg, in an appraisal of sample homogeneity. Results will be presented to characterize the overall recovery efficiency of the aqua regia leach procedure and to assess the realistic capabilities of the technique for samples of varying matrix and PGE mineralogy.
Impact of ICP-MS on geoanalysis
Authors: Hall G E M
Published: November 2013

The extremely variable composition of geological materials, particularly that of rocks and soils, poses an immense challenge to the accurate and precise multielement determination of trace and ultra-trace level constituents. Hence, it is not surprising that
numerous geoanalytical laboratories leapt with both feet into ICP-MS in its early days, with promises of such features as simple spectra with few interferences, wide linear dynamic range, and detection limits in solution in the order of 0.01-0.1 ngþml-1. Inevitably, we have since learned to temper
enthusiasm with caution, as fundamental and applied studies of matrix-induced interferences have evolved. However, new doors have been opened in geoanalysis by this technique whose ultimate power is yet to be fully exploited. Undoubtedly two of the most significant achievements to date lie in the
determination of two groups of elements: precious metals and the REEs. The collective determination of Au and the PGEs (Pt, Pd, Rh, Ru, Ir, Os) by commercial laboratories has been the sole domain of NAA. Application of ICP-MS in this field offers the advantages of superior sensitivity for Pt, Pd,
and Ru and rapid turnaround time without the necessity of lengthy decay periods. This technique has also found a niche in the determination of Au, Pt, and Pd following Pb fire assay where previously ICP-AES and AAS have dominated. As in other applications the critical factor affecting detection
limits is the purity of the reagents used, not the sensitivity of ICP-MS. Biogeochemical exploration for Pt and Pd has now become a practical tool, owing to the reasonable quantity of sample required to attain adequate detection levels. This technique now reigns supreme in its proven ability to
determine all REEs down to 1 ngþg-1 if a separation step is incorporated into the procedure. This capability together with abundance level detection of high field strength elements (e.g. Nb, Hf, Ta) is greatly facilitating tectonic interpretation studies. The application of surface and ground waters
in geochemical exploration is yet to be thoroughly evaluated but the ability of ICP-MS to analyze waters directly and adequately for many trace elements assures it a key role. Research into the introduction of gaseous hydrides into the ICP mass spectrometer is currently active in an effort to
improve detection limits over those offered by ICP-AES. These comprise some of the accomplishments reviewed in this presentation. Progress in the use of alternative sample introduction techniques and calibration strategies is also discussed.
Commercial appliations of neutron activation analysis
Authors: Hoffman E L
Published: November 2013

The theory behind instrumental neutron activation analysis (INAA) will be discussed. Various applications of INAA to exploration geochemistry will be described. The advantages and disadvantages of the technique will be shown and the role of INAA amidst other
instrumental techniques described. Cost, turnaround time, ultrasensitivity for certain elements, the nondestructive nature of analysis, and the high precision and accuracy of analyses have combined to make INAA an indispensable method for multielement analysis on virtually all geological matrices.
Humus, vegetation, heavy minerals, lake bottom sediments, as well as rocks and soil analysis by INAA are some of the major applications of the method. As many as 60 elements can routinely and easily be determined by INAA.
An alternative method of sample preparation for X-ray fluorescence analysis of rocks
Authors: Izquierdo G , Guevara M
Published: November 2013

The present work deals with the adaptation of a method for sample preparation in the determination of the ten major elements in rocks, using a Siemens SRS 200 spectrometer. Initially the analysis was carried out employing lithium tetraborate glasses; due to the
lack of materials such as platinum crucibles, furnaces, automatic polishing machines, and even reagents, we decided to look for another method of sample preparation. In order to reduce time and materials cost, compact discs made of high purity wax and powdered rock were prepared, in such proportion
to obtain a full and hard disc. So, depending on the composition of the rocks, it was necessary to increase the amount of wax, thereby resulting in the undesirable effect of high dilution of samples. Another method tested was the preparation of discs from powdered cellulose and rock. This method was
adopted since it offers some advantages such as low dilution and low cost; it is possible to determine all elements in the same pellet with a short preparation time. To prove the effectiveness of this method compared to that based on fusion, two series of the same geochemical reference standards
were prepared both ways. Calibration curves were generated by least-squares linear regression. In order to evaluate the reproducibility of these two methods, duplicates of several samples were prepared, some being geochemical standards and others geological materials analyzed by different
laboratories. Preliminary data show that accurate and precise results can be obtained by either of the two preparations. Additional analysis will be done to confirm that cellulose pellets do provide an alternative method of sample preparation for the XRF analysis of rocks.
Application of plasma spectrometry (ICP-AES, ICP-MS) to the analysis of sediments: an evaluation study using standard reference materials
Authors: Jarvis I , Jarvis K
Published: November 2013

Increased interest in the geochemistry of sedimentary samples by geologists and environmental scientists has led to the release of a range of new sedimentary standard reference materials (SSRM). Many of these standards, however, remain relatively poorly
characterized when compared with established igneous rock reference materials. Lack of characterization is a result of a number of factors, including: (a) sediments vary considerably in composition and most differ greatly from igneous rocks; (b) few geochemical laboratories specialize in sediment
analysis, and therefore few have instruments which have been calibrated for this type of material; (c) many trace elements occur at low levels in sediments, and consequently are difficult to determine by most routine analytical techniques; (d) many SSRMs have been released relatively recently and
have not yet been characterized by a sufficiently large number of laboratories and/or techniques. We have used a combination of inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ICP-mass spectrometry (ICP-MS) to study the compositions of a range of generally available SSRMs:
Geological Survey of Japan (JSd-1, JSd-3 stream sediments; JCh-1 chert; JLk-1 lake sediment; JSl-1, JSl-2 slates; JDo-1 dolomite; JLs-1 limestone), National Institute of Standards and Technology, U.S.A. (1c argillaceous limestone; 88b dolomitic limestone), National Research Council of Canada
(BCSS-1, MESS-1, PACS-1 marine sediments), United States Geological Survey (MAG-1 marine mud; SCo-1 Cody shale; SGR-1 Green River shale) and University of Liege (AWI-1 shale; CCH-1 limestone; DWA-1 dolomite; PRI-1 psammite; SBo-1 schist). Samples were prepared in triplicate by three independent
techniques: (1) fusion with lithium metaborate and digestion in dilute HNO3; (2) digested in sealed microwave vessels using HF, HNO3, and HClO4 acids, evaporation, and dissolution in dilute HNO3; and (3) grinding with agate beads in a Na4P2O7 suspending agent. The first two preparations were
analyzed by solution nebulization ICP-AES and ICP-MS; samples prepared by the third method were analyzed by slurry nebulization ICP-MS only. The advantages and disadvantages of ICP-AES and ICP-MS for major and trace element analysis will be discussed, and procedures will be suggested for the routine
determination of a wide range of elements in sedimentary materials by plasma spectrometry.
Review of literature (accepted, certified, concensus) values of standard reference materials with consideration of geochemical relationships
Authors: Jenner G A , Longerich H P , Jackson S E , Fryer B J
Published: November 2013

There is an increasing number of rocks and minerals being made available to geochemists, for use as calibration standards and reference materials. Considerable effort is expended in compiling, analyzing, and distributing the analytical data collected on these
materials. One aspect of the data evaluation, which is clearly neglected is consideration of the "geochemical" behaviour of the elements. Geological processes most often follow a set of "rules", based upon crystallography, chemical bonding, and solid-liquid-gas equilibria, which maintain certain
relationships between elements on primitive mantle normalized diagrams þ integrating lanthanide, alkali metals, alkaline earth, Group IV, and Group V elements. It is possible to use these geochemical rules in evaluating data for the reference materials. One of the advantages of ICP-MS is that it
provides extensive coverage of many of the important geochemical groups. Use of this feature, in conjunction with knowledge of the "geochemistry" of the reference materials, makes it possible to evaluate not only the ICP-MS data, but the recommended values as well. We will present data, particularly
for the newer USGS basalt standards, which clearly illustrate deficiencies in the literature data.
Use of geochemical reference standards in a quality control/quality assurance program
Authors: Johnson W M
Published: November 2013

A discussion is given of the role played by Geochemical Reference Standards in establishing and maintaining a Quality Control/Quality Assurance program in a commercial geochemical/assay laboratory. The discussion includes the development of internal standards and
their certification with respect to internationally recognized standards. The discussion relates to standards used for geochemical trace analysis, ore grade assays and the analysis of concentrates for establishing the values of shipments. The source, preparation, and storage of the various types of
internal standards developed is also covered.
Derivation of recommended values from compilations: an opinion
Authors: Kane J S
Published: November 2013

In the July 1989 special issue of Geostandards Newsletter, Govindaraju indicated that a minimum of 40 analytical results, arrived at by at least four independent methods, are needed to derive working values or recommended concentrations, and that the working
values are improved when derived from an even larger data set. To make the needed data more readily available, he suggests the desirability of annual updates for geochemical reference sample databases. It is the purpose of this opinion piece to comment on these issues. First, the need for 40 or more
analytical results to derive working values is a direct contradiction to the National Institute of Standards and Technology (NIST) approach in producing standard reference materials (SRMs). NIST certifies the elemental concentrations in SRMs, based on agreement between results from a minimum of
three independent methods of analysis. Recently, the United States Geological Survey adopted a similar criterion in deriving recommended values for the shale reference sample, SDO-1 (1989). Consensus values published by Gladney et al. (1987) do not differ significantly from original certified
values, despite being based on as many as 50 independent results. Admittedly, the Gladney et al. (1987) compilation provides information on many elements not covered in the earlier certification program, and is, in this sense an improvement. However, the fact that consensus values for 19 elements in
NBS coal SRM 1632, for example, are based on five or fewer literature values, and an additional 12 values are based on six to ten results, is itself a contradiction to the Govindaraju statement that 40 or more analyses are required for appropriate derivation of working values. It indicates the
futility of annual updates to improve the quality of recommended concentrations, since even these few results were obtained only over twelve years. Comparison of Flanagan's (1976 and 1984) original compilations for USGS geochemical reference samples with those published later by Gladney and
Roelandts (1988a, b) similarly leads to the conclusions that 1) good working values can be derived from fewer than 40 laboratory results, providing all are obtained under stringent quality control, and 2) annual\ updates of compilations are likely to be redundant for all but a few
elements.
The current status of geoanalysis at the IRMA
Authors: Li J
Published: November 2013

The Institute of Rock and Mineral Analysis (IRMA) was founded in 1978 on the basis of the Beijing geological laboratory of the Chinese Ministry of Geology and Mineral Resources established in 1952. The institute itself is an exclusive research center of
geoanalysis in China and takes full responsibilities for conducting: (1) development of new analytical techniques and methods for geoanalysis; (2) study, preparation, and analysis of geological reference materials; (3) analysis of complicated and difficult geological samples; and (4) technological
services. IRMA now has a qualified staff of some 140 scientists and technicians and owns various analytical instruments for carrying out routine analysis and analytical method development. This talk will briefly present the current status of geoanalysis at the institute and the achievements of
development research over the past years in the areas of arc source emission spectrometry, laser ablation ICP-ES, ICP-OES, ICP-MS, AAS, XRF as well as spectrophotometry and polarography.
RI-TOFMS analysis for trace elements in geological materials
Authors: Ma W -Y , Hui Q , Wen K -L , Xu X -Y , Chen D
-Y
Published: November 2013

The direct and efficient detection of the concentration and the isotopic abundance of some trace elements, particularly the precious metals and the rare-earths, in geological materials is of great interest in geochemical exploration. This challenge has not been
fully met using traditional techniques because of a lack of sensitivity. In recent years, a new method þ Laser Resonance Ionization Time-Of-Flight Mass Spectrometry (RI-TOFMS) þ has been investigated to solve this problem satisfactorily. The principal advantages are its high sensitivity and
selectivity, as well as the possibility of direct analysis for trace constituents in various samples without appreciable matrix effects. We have been achieving the direct determination of Au and PGEs in geological materials with detection limits below 1 ppb; this work will be
described.
BANKAN-the batch of computer programs to accumulate and process elemental analyses of geological materials
Authors: Martynov K V
Published: November 2013

Having obtained an immense quantity of analytical data every geochemist needs a computer program to accumulate and process this information; BANKAN helps you in this purpose. The bank of analyses consists of an unlimited quantity of informational blocks
("notes"). It is created as sequential mode file(s) on hard disk or diskette. Every "note" has an arbitrary structure (Table 1), determined by the user, and saved to file altogether with inputted data. The "note" consists of: 1) string variable þ name of "sample"; 2) arrays of string variables
("lists") þ descriptions of "sample"; 3) arrays of string variables þ the names of analyzed "minerals"; 4) arrays of string variables þ the names of analyzed "elements" in each "mineral"; 5) arrays of numeric variables þ the means of element contents in "minerals" ("analyses"). BANKAN includes three
BASIC-programs. The first one (INTO) is designed to create the "note" structure, i.e., to determine the quantity and dimensions of arrays ("list", "minerals", "elements"), and to name them. Besides that, this program is used to input data. The second program (SORT) helps to locate all "notes" having
certain signs. These signs are the names of "lists" and their contents, the names of "minerals" and "elements". The third program (OUT) is employed to look through each "note" (sequentially or in the search regime, using the name of "sample"), to process the numeric data and to create a file(s) for
printing. The processing of data includes: 1) the calculation of additional relationships (stoichiometric coefficients, mole fractions, etc.), which are determined by the user; 2) looking through "analyses" on a plot (up to 8 plots simultaneously), the axes of the plots are determined by the user;
and 3) statistic processing. The last one includes calculations of the middle means, confidence intervals, standard deviations, variational coefficients, and the matrix of correlation coefficients. Statistic characteristics are calculated for Student's distribution with a confidence probability of
0.95. Initial and calculated data could be seen on a screen and saved to file(s) for printing as a convenient table. The programs are suitable for BASIC-interpreters as well as for BASIC-compilers. Colour graphics are used in these programs. BANKAN's users have the possibility to keep in compatible
form an immense quantity of analyses of geological samples and their descriptions.
The challenges in managing a geoanalytical laboratory in Zimbabwe
Authors: Nyampingidza E , Tindwa R M
Published: November 2013

In Zimbabwe, most instruments and reagents required for analysis are imported, therefore an analytical laboratory is greatly affected by lack of foreign currency, as is any other establishment in the country. When the foreign currency is made available for such
use, the waiting period for the importation of these vital requirements can be unbearable, from 6 months to 18 months or more for an instrument to be delivered. Meanwhile, both research and routine analytical work suffer. Although a great deal of import substitution is taking place, locally
manufactured equipment is often of very poor quality and one would be correct to call them substandard (e.g., heating mantles, electric furnaces, etc.). The equipment breaks down so often that perhaps, in the long run, one would rather wait patiently for the imported items. Lack of modern
instruments is a problem facing the whole country. Except for atomic absorption spectrophotometers, instruments such as the inductively coupled plasma emission spectrometer or the electron microprobe are obsolete. To acquire spare parts for such instruments becomes a mammoth task for any laboratory
manager. Coupled with the shortage of instruments, is the shortage of well trained staff who can execute competently the tasks given to them and few technicians are trained to operate instruments such as the X-ray fluorescence spectrometer, the electron microprobe, or the scanning electron
microscope. Service and repair of such instruments is still carried out by technicians from the respective parent companies who supply these instruments. This service is quite expensive, up to Z$1000 per day. These and many other problems make the whole job of managing a geoanalytical laboratory in
Zimbabwe a bigger challenge to a chemist than most people realize. Despite all these setbacks, one is still expected to produce good, accurate results on international standards, since even a small developing country like Zimbabwe sells its minerals at the London Metal
Exchange.
ICP emission spectroscopy with ultrasonic nebulization-application to waters and soils
Authors: Nygaard D D , Bulman F , Alavosus T
Published: November 2013

Ultrasonic nebulization has been applied primarily to the analysis of relatively clean waters for purposes of environmental monitoring. In this application, it improves ICP detection limits by approximately an order of magnitude. In addition, accuracy and long
term stability of the technique have been shown to be sufficient to meet quality control requirements such as those employed by the U.S. EPA Contract Laboratory Program. However, performance of ultrasonic nebulization is suspect on more complex samples. It is reputed to be more strongly affected by
matrix variation than standard pneumatic nebulizers, and memory effects are reportedly more severe. This paper explores the possibility of expanding ultrasonic nebulization into soils analysis. It includes a systematic study of the effects caused by matrix elements and by acids used in sample
preparations. Sensitivity enhancement is examined as a function of sample matrix, and memory effects are quantified.
Objective evaluation of precision requirements for geochemical analysis using analysis of variance
Authors: Ramsey M H , Thompson M , Hale M
Published: November 2013

The pursuit of high precision in geochemical analysis has no inherent limit. An appropriate analytical precision requirement can be set, however, by comparing the "analytical variance" with the two other sources of variance in geochemical data. The purpose of a
geochemical survey is to give a description of the geochemical variation of a region. This can be expressed in terms of the natural "geochemical variance" of the area. The information content is diminished by the two processes of measurement: the act of taking a sample adds a random error with
"sampling variance"; and the act of chemical analysis adds another random error with "analytical variance". In order to optimize the analytical variance for cost-effectiveness rather than simply to minimize it, all three variances must be estimated. This requires that the traditional analytical
quality control scheme be extended to include the total measurement process, rather than only the "analytical" portion. Such a Total Analytical Quality Control Scheme (TAX) requires some duplication of field samples and the duplicate analysis of each field duplicate. The Analysis of Variance (ANOVA)
is then used to separate the three components of the total variance. For a clear description of the natural geochemical variance the combined sampling and analytical variances for the data should comprise, say not more than 20% of the total variance. If this figure is exceeded then these
extraneous variances should be reduced. The decision as to whether this reduction requires improved sampling variance or analysis variance can also be made from this ANOVA. As a general rule, the analytical variance should comprise not more than 5% of the total variance. If, on the other hand,
the analytical variance is less than 0.5% of the total variance then needless expense has been incurred and the natural geochemical variation can be adequately described with less precise methods of analysis. Similar arguments can e applied to sampling variance. For the analytical geochemist the
combination of TAX and ANOVA can therefore provide a realistic target for analytical precision. For the field geochemist they provide a quantitative tool for the design of geochemical surveys. They allow the optimization of both sampling and chemical analysis for a given terrain to reveal
geochemical patterns at minimal expense.
Matching analytical capabilities to client requirements
Authors: Rao V K
Published: November 2013

In mineral exploration, the client requirements of geoanalysis are for the purpose of (i) locating the target areas and (ii) for detailed exploration. For the former, a vast number of samples are required to be analyzed as rapidly, accurately, and economically as
possible for the principal elements. Simple chemical methods are being replaced by instrumental techniques like XRF, ICP, and AAS. For detailed exploration, drill core and exploratory mining samples are analyzed for the principal, rare, and deleterious elements. Elaborate chemical and spectral
methods are employed to meet the requirements. Mineral analysis is carried out by XRD, DTA, and microscopic methods.
Determination of major, trace, and rare-earth elements in six Japanese rock standards
Authors: Rathi M S , Khanna P P , Saint N K , Mukherjee P K R
Published: November 2013

Six new Japanese geological reference materials (JA-2, JG-2, JG-1a, JP-1, JB-1a, and JF-1a) were analyzed for 28 elements (Si, Al, Ca, Mg, Na, K, Fe, Ti, Mn, P, Ba, Cu, Cr, Co, Ce, Dy, Li, La, Ni, Nb, Nd, Rb, Sr, V, Y, Yb, Zr, and Zn). Since these materials have
been released only recently, the values reported for major as well as trace elemental concentrations are not well characterized (Govindraju, Geostandards Newsletter Special Issue, 1989). The analysis of the samples was carried out over a period of 30 days with at least ten repetitions each using
different techniques like XRF (energy dispersive) ICP-AES, AAS, and flame photometry. Accuracy and precision in the analytical data were monitored using well established USGS, CRPG, and NBS certified rock standards. The results obtained for elements measured by more than one method were found to be
consistent among themselves. In most of the cases our analytical data agree with the consensus values for these standards to within +/- .5 to 3 relative per cent for major elements and +/- 2 to 10 relative per cent for trace elements. The new values proposed in the present work, with few exceptions,
are in good agreement with the values reported in literature and should be useful in a compilation of recommended values for these new standards.
Rhenium as a neutron flux monitor in the neutron activation analysis of large mass geological samples for gold and other elements
Authors: Robertson R , Stuart D C
Published: November 2013

In recent years, some commercial laboratories have routinely determined gold and many other elements in large mass exploration samples using neutron activation analysis. The sample masses taken, typically in the range 5-50 g, are in keeping with the sample sizes
traditionally used in fire assay. In order to keep throughput high and irradiation costs low, it is common to irradiate 10 to 20 samples together in 5 cm diameter by 30 cm long bundles in positions at the periphery of reactor cores. In these positions, axial and radial neutron flux gradients and
neutron spectrum variations must be well accounted for if good analytical data are to be produced. There are many properties desirable in a good neutron flux monitoring system for the above outlined purpose. This poster paper describes one system which has been found very effective in the analyses
of hundreds of thousands of samples over a five year period. The system is based on the use of the element rhenium incorporated in a self-adhesive label which is attached to each sample. The procedure used for rhenium doping of the carrier labels is outlined. Neutron flux profiles of irradiation
positions as determined through activities induced in Re-185 and Re-187 in two different reactors in both thermal and epi-cadmium positions are presented. The responses of Re-185 and Re-187 are compared with the responses of over twenty elements of analytical interest, covering examples of elements
whose activations are closely tracked by one or other of the rhenium isotopes with changing neutron spectrum shape, and examples of other elements whose activations are not so well tracked. The list of elements includes gold, antimony, arsenic, chromium, lanthanum, scandium, silver, sodium,
tantalum, tungsten, uranium, thorium, and zinc. The merits of simultaneous gamma counting of a rhenium flux monitor and associated sample with data acquisition into the same spectrum are discussed. The usefulness of this procedure in controlling sample counting geometry and rate related counting
losses is indicated. Experience with the occurrence of rhenium in the samples themselves, which would tend to discourage simultaneous spectral acquisition, is also outlined.
Determination of the combined water (H2O+) in 41 geological reference samples by an infrared absorption method
Authors: Saikkonen R J
Published: November 2013

The combined water (H2O+) in 41 geological reference samples was determined by an infrared absorption method. After combustion at 1100oC without flux, samples were analyzed with the LECOo moisture analyzer RMC-100. In this method the dry sample is loaded into a
resistance furnace, H2O+ is driven from the sample with nitrogen gas and is passed through the infrared cell, where water vapour absorbs IR energy at a specific wavelength. This wavelength is selectively passed through a filter to an IR sensor, where the concentration of H2O+ is detected as an
energy level. The signal is amplified, rectified, and digitized. The data are sampled twice a second and after linear corrections the data are integrated to find the water concentration. The result is displayed as weight per cent. The IR cell linearization was checked with rock standards and G-2,
MRG-1, BE-N, PCC-1, and UB-N were used as the calibration standards. The method is capable of determining H2O+ at level 0.01 þ 14% if the sample weight is 0.5 g. The sample calibration should be done at the start of each day and in-house reference samples should be analyzed periodically to
confirm proper operation of the instrument. In routine work, where samples contain H2O+ at the level given above, the calibration of the instrument with one rock standard is sufficient. The present results were in generally good agreement with published data. The coefficients of variation follow the
general trend of large coefficients for samples containing the least amount of the constituent and of small coefficients for samples containing the greatest amount (BIR-1: H2O+ = 0.10%, CV = 15%; BX-N: H2O+ = 12.26%, CV = 2%). The detection limit, defined as three times the standard
deviation of 20 blank determinations was 0.004% H2O+. The practical detection limit of the method is about 0.01% H2O+, and the time required for each determination is not more than 10 minutes.
Prompt gamma neutron activation analysis of SRMS at the McMaster Nuclear Reactor in 1990 and the future prospects
Authors: Shaw D M , Smith P L C
Published: November 2013

The 2 Mw McMaster Nuclear Reactor has operated a thermalized neutron beam with a dedicated prompt gamma neutron activation analysis (PGNAA) system for about six years, for determination mostly of B, but also for Gd, Sm, and H. The horizontal neutron beam is
filtered through silicon and sapphire, giving a flux of 6 x 107nþcm-2þs-1 with a Cd ratio >100 at the sample position, 250 cm from the reactor core. Samples are irradiated in Teflon or polyethylene capsules which can hold up to 7 g of powder and gamma rays are received in an Aptec 12%
efficient intrinsic Ge detector connected with standard multichannel counting equipment. The usual peaks are: B 478 keV, Gd 182 keV, Sm 334 and 439 keV, H 2223 keV. The blank signals from an empty capsule correspond to sensitivity limits of: B 0.4 þg, Gd 0.2 þg, Sm 0.4 þg, H 100 þg. The system is
calibrated using appropriate pure chemicals, deposited from solution in a base of silica powder. Precision is monitored by repeat measurements and averages 3-5% (1 standard deviation) for all four elements, except for concentrations near the detection limits. Accuracy is surveyed by including
two or more SRMs in each analysis batch. In most cases our results of repeated analysis of many SRMs show agreement with results from other laboratories, using other methods. If present plans can be carried out, the reactor will be retrofitted with a new core, using the so-called MAPLE design. This
will increase the power to 12 Mw and, in addition, the enhanced thermal neutron flux will be generated using a methane cold source. The sensitivity of PGNAA will increase by several orders of magnitude.
Analysis of standard reference materials for thallium, gallium and indium
Authors: Vaive J E , Hall G E M
Published: November 2013

At present, there are few methods available for the determination of Tl, Ga, and In in geological materials at or below the average crustal abundance level. A method capable of determination down to 10 ppb for all three elements has been developed at the
Geological Survey of Canada. The samples are decomposed using a multiacid (HCl-HF-HClO4-HNO3) `total' decomposition procedure, extracted in a suitable form into MIBK and analyzed by graphite furnace atomic absorption spectrometry. Palladium is used as a matrix modifier to remove gas phase
interferences which would result in significantly higher detection limits. This methodology was evaluated by the analysis of international standard reference materials and results presented here compare favourably with accepted values.
Applications of inductively coupled plasma mass spectrometry (ICP-MS) to geoanalysis
Authors: Yin N
Published: November 2013

ICP-MS has received special attention from geoanalysts due to its unique features, namely, high detection power, simple spectra, and rapid isotopic ratio capability. However, real-world geoanalysis has shown that there are certain limitations preventing this
technique from giving full play to its advantages. These limitations, in many cases, relate to sampler orifice clogging with relatively low dissolved solids and signal suppression/enhancement in the presence of relatively low contents of matrix elements. Moreover, sample dissolution procedures
conventionally used also pose limitations on achieving the best possible analytical results. A VG PlasmaQuad system was installed in the Institute of Rock and Mineral Analysis in 1986 and is now in routine use for geoanalysis. This talk will summarize geoanalytical applications which have been
developed at this institute and present analytical data of trace elements and lead isotopic ratios for various geological samples and standard reference materials.
The determination of major and trace elements in geological materials samples by XRF
Authors: Zhai Q
Published: November 2013

Eight major elements and 14 traces have been determined by pressed pellet XRF using an ARL 8680 SIM/SEQ X-ray spectrometer. Samples are ground to less than 200 mesh and pressed into pellets using a paraffin-boric acid mixture as adhesive. Corrections are made for
overlapping spectra on Ba, Y, Zn, and Th; the Compton scattered line is used as internal standard to improve accuracy. Matrix effects are corrected for by the use of the Traill-LaChance equation or the Lucas-Tooth equation. Analysis of the pressed rock or sediment powder pellet for 22 elements
requires about nine minutes of machine time; 130 samples can be analyzed in 24 hours. Tables 1 and 2 show the accuracy and precision, respectively, obtained by this method.
A new catalytic polarographic system for the determination of trace amounts of tungsten and its application in geoanalysis
Authors: Dan D , Re J
Published: November 2013

A new catalytic polarographic system for the determination of trace amounts of tungsten is described. It is found that tungsten-MBT (2-mercaptobenzothiazole) gives a sensitive catalytic hydrogen wave at -1.10 V (vs. SCE) in strongly acid medium. The linear
relationship occurs between peak height and tungsten concentration over the range of 0.004-1.4 þg/mL W in a solution of 0.9 M H2SO4- 2% NaCl- 0.01 þg/mL MBT. The influence of foreign ions on the wave has been examined. The experiments show that the method is rapid, simple, sensitive, and has a
wide linear range. The method is suitable for the analysis of samples in a wide variety of matrices, and has been applied to determining trace amounts of tungsten in six Chinese stream-sediment reference standard materials with satisfactory results without any separation. The relative error found is
from 3.7% to 13.7%. The properties of the catalytic polarographic wave have been investigated.
Implications of sampling statistics in using slurry sample introduction for atomic absorption spectrometric analysis of geochemical reference samples
Authors: Kane J S , Xu Z
Published: November 2013

A number of investigators have used slurry sample introduction for the atomic absorption spectrometric analysis of a variety of materials. A unique application of the method, however, is evaluation of the degree of homogeneity of reference samples. For
geochemical samples, the expected analytical error attributable to subsampling from mineral mixtures can be calculated from grain size and component mineral densities, following the approach of Ingamells. This paper presents these calculations for a number of elements in specific geochemical
reference samples for which known mineralogy predicts inhomogeneous distribution of analytes. Measurements are made for Cr in the reference dunite, DTS-1, and for a number of elements in the certified reference sulphide ore, MP-1a, at two different subsample weights, using slurry atomization atomic
absorption spectrometry. The experimental and calculated sampling parameters are compared, and the feasibility of using the slurry technique for establishing homogeneities and sampling constants of geochemical reference samples is demonstrated.
An on-site method for measuring aluminum speciation in shallow well water samples from areas exposed to acid deposition
Authors: Meranger J C , Lett R E , Pickering T
Published: November 2013

An on-site procedure involving filtration and ion exchange has been developed to study aluminum speciation in water samples collected from shallow wells. Immediately following collection the samples are mixed continuously with Chelex 100 ion exchange resin for
eight hours. At intervals during the mixing cycle subsamples of the water are taken, preserved with acid, and later analyzed for aluminum by graphite furnace atomic absorption spectrophotometry. The method has been applied to an examination of Al chemistry in the water from shallow wells in rural
areas of eastern Canada where there is evidence of exposure to the impact of acid deposition. The results show that in weakly acid wells much of the Al remains in polymeric form whereas in more strongly acid waters (below pH 5.8) the Al is predominantly in an easily extractable monomeric
form.
The challenges in managing a geoanalytical laboratory in Zimbabwe
Authors: Nyampingidza E , Tindwa R M
Published: November 2013

In Zimbabwe, with most of the instruments and reagents required for analysis being imported, an analytical laboratory, like any other establishment in the country, is greatly affected by lack of foreign currency. When the foreign currency is obtained, the waiting
period for the importation of an instrument can be from 6 to 18 months or more. Meanwhile, both research and routine analytical work suffer. The instruments available in most cases are obsolete and replacements are either too late in coming or never come at all because nobody produces them any more.
Lack of instruments is a problem facing the whole country. The other problem is the shortage of well trained staff who can competently execute the tasks given to them. These and many other problems make the job of managing a geoanalytical laboratory in Zimbabwe a bigger challenge to a chemist than
the analysis itself.
Quantitative SIMS analyses of REEs in silicate minerals: choice of the standard for natural and glassy matrix
Authors: Ottolini L , Bottazzi P , Vannucci R
Published: November 2013

Five silicate samples þ three hornblendes and two kaersutites þ were chosen to test the empirical approach to calibration curves (working curves) and relative sensitivity factors in the quantitation of rare-earth elements (REE) in amphiboles, by means of
Secondary Ion Mass Spectrometry (SIMS). The measurements were carried out with a Cameca IMS 4F ion microprobe, using a moderate energy filtering (-80 V offset), from the maximum of the energy distribution, with an energy window of 25 eV, in order to eliminate complex ion interferences. One of the
two kaersutites, investigated both as a crystal mineral and a fused glass pellet, did not reveal evident systematic effects due to matrix structure; La and Ce seemed to ionize better in glass (crystal/glass intensity ratios ranging from 0.90 to 0.91), an opposite trend occurring for heavy REEs
(e.g., 1.06 for Dy and 1.11 for Yb). The tested inhomogeneity of the other samples prevented the addition of more experimental data and no simple explanation seems available at this point. Relative sensitivity factors from our present investigation were successively compared with those calculated
from an ensemble of mafic-ultramafic international rock standards fused in glasses (differences are about 18% for Nd and Sm, 2% for Eu), and with those obtained from natural minerals, namely clinopyroxene and garnet (differences of 23% for Sm and <1% for Er). It is
concluded that relative sensitivity factors from fused glasses of amphiboles can be employed in the REE analysis of natural amphiboles (which are naturally more inhomogeneous). They could also be tentatively used in the analysis of silicates, over a wide compositional range, especially for heavy
REEs, when suitable standards are not available.
Advantages of the fundamental algorithm in quantitative XRF analysis
Authors: Rousseau R M
Published: November 2013

A modern theoretical method using the Fundamental Algorithm to correct for matrix effects in X-ray fluorescence (XRF) analysis is described. This powerful quantitative method combines the practical flexibility of influence coefficient concepts and the theoretical
exactness of the fundamental parameter technique. This method is in full agreement with the treatment of the physics as proposed by Sherman and can be applied to the analysis of any sample type. It offers the maximum of accuracy limited only by the quality of sample preparation. The special
calibration procedure associated with the Fundamental Algorithm is explained. This procedure allows the matching of theoretical formalism to experimental data of each individual laboratory. Finally and obviously, this approach requires a computer program to be applied. Some important guidelines are
given to help XRF analysts to select the XRF program appropriate to their needs.
Physical properties of Canadian kimberlites, Somerset Island, Northwest Territories, and Saskatchewan
Authors: Katsube T J , Scromeda N
Published: November 2013

Physical properties (density, magnetic susceptibility, electrical resistivity, porosity, formation factor, surface resistivity) were measured on 26 Canadian kimberlite samples for information required in exploration of kimberlite-hosted diamond deposits.
Following previous studies on fewer samples and parameters, this paper provides a more complete set of measurements to link geophysical parameters to geological characteristics. Results suggest that porosity is a major factor controlling density, formation factor and electrical resistivity of these
kimberlites, with additional factors of significance influencing resistivity. There are indications of porous kimberlites being altered, and nonporous ones being fresh. Magnetic susceptibilities seem unrelated to other parameters. Archie's coefficients may show characteristics unique to kimberlites.
This is primarily a documentation of physical properties of some kimberlite samples. Continuing studies on quantitative relationships between mineralogy (primary and secondary), petrographic textural type (crater, diatreme, or hypabyssal facies), and physical properties are expected to provide
geophysical signatures unique to kimberlites.
Potassic magmatism in the Milk River area, southern Alberta: petrology and economic potential
Authors: Kjarsgaard B A
Published: November 2013

Potassic rocks of Eocene age known as the `Sweet Grass Intrusives' outcrop as hypabyssal (dykes, plugs) intrusive rocks as well as extrusive rocks (agglomerates, lahars) in the Milk River area of southern Alberta. These rocks represent the northernmost extension
of the 69-27 Ma Montana alkaline province. Combined whole-rock major and trace element chemistry, mineralogy, and mineral chemistry studies demonstrate that these rocks are minettes and that they are similar to other minettes (Highwood and Bearpaw mountains) from the Montana alkaline province.
Minette pyroclastics at the Coulee 29 vent complex are the only known preserved extrusive rocks in the Sweet Grass area (Montana or Alberta). The economic potential (diamonds, gold, PGE) is considered to be low.
Caring during clinical practice: Midwives’ perspective
Authors: Chokwe Mmajapi E. , Wright Susan C.D.
Published: November 2013

Background: Caring forms the core of nursing and midwifery. Despite caring being an important emotional aspect of midwifery and nursing, there are general public complaints about uncaring behaviour in midwifery. Therefore, there is a need to explore caring from midwives’ point of view with the hope of identifying solutions and recommendations for midwifery practice. Furthermore, the study aimed to stimulate debate and discussion about the caring behaviour of midwives.Objective: To explore caring during clinical practice as perceived and experienced by midwives.Method: The study was contextual, exploratory and qualitative. The participants were midwives working in state and private hospitals in Tshwane, South Africa where BTech II and III midwifery learners were allocated for work integrated learning (WIL). Data collection was carried out through self-report using a questionnaire and focus group. Questionnaires were distributed to 40 midwives at private and state hospitals in Tshwane. This was followed by two focus group sessions to ensure that data is enriched. The hermeneutic interpretiveapproach was used to analyse data, and analysis continued until saturation.Results: Themes of caring and uncaring related to patient care and midwives emerged. The findings illustrated that the midwives had excellent theoretical knowledge of caring, but some of them did not display caring behaviour during clinical practice.Conclusion: Some of the midwives did not display caring behaviour. Implication for practice was provided based on the research findings. Recommendations included measures of improving caring behaviours during midwifery practice.