Isotopic analysis of7LiOH samples by SSMS

A methodology for the isotopic determination of lithium in enriched⁷LiOH.2H₂O samples by SSMS is described. The photoplate emulsion calibration curve was not used. The accuracy of the results was checked against the analysis of LiOH.2H₂O with natural isotopic composition, and it was found that the result obtained was accurate within 5% with respect to the published natural value. The accuracy was improved using an enriched in⁷Li reference sample. The technique was applied to the analysis of batches of⁷LiOH.2H₂O to be used in a nuclear power reactor to control the pH in the water cooling system.SSMS: Spark Source Mass Spectrometry.     

A photoplate calibration technique applied to the determination of hafnium in zirconium by SSMS

A photoplate calibration procedure is suggested for spark source mass spectrometry /SSMS/ with photoplate detection. The technique uses the Churchill two-line method applied to the two stable isotopes of copper. The calibration curve thus obtained is split into fragments and each fragment is approximated by a polynomial. The method was applied for the quantitative determination of Hf as impurity in zirconium sponge obtained from a pilot plant dedicated to the depletion of the hafnium content in zirconium by fractional crystallization.     

Control of the10B/11B isotopic ratio in H3BO3 samples by SSMS

The¹⁰B/¹¹B isotopic ratio in the H₃BO₃ presented in the liquid moderator of a nuclear reactor is used as monitor of the performance of the reactor during the first year of operation. Usually this determination is performed by TIMS due to its high precision. An alternate technique to thermal ionization mass spectrometry /TIMS/ for the determination of the¹⁰B/¹¹B isotopic ratio by SSMS is presented. The modifications introduced in the general analytical method produced very good results. Furthermore, the relative standard deviation was 5% against the typical value of 10–20%.SSMS: spark source mass spectrometry.     

Determination of the sulphur content of geological samples by X-ray fluorescent analysis

Summary The sulphur content of ultramafic and basic rocks is determined by X-ray fluorescent analysis with pressed powder pellets. A commonly marked cellulose powder and wax are taken as diluent. Two analysing crystals, PET and graphite, are compared. The linear calibration curve reaches from 50 ppm to 1.0 weight-%, with a detection limit of 90 and 45 ppm, respectively. If the standard rock is of nearly the same matrix as the examined samples, no calculated matrix correction is necessary.

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Schwefelbestimmung in geologischen Proben durch Röntgenfluorescenz-Analyse

Zusammenfassung Eine Methode zur röntgenfluorescenzanalytischen Schwefelbestimmung an ultrabasischen und basischen Gesteinen wird beschrieben. Die Messung erfolgt an Preßtabletten mit handelsüblichem Cellulosepulver oder Wachs als Verdünnungsmittel. Zwei Analysatorkristalle, PET und Graphit, werden verglichen. Die lineare Eichkurve umfaßt den Konzentrationsbereich zwischen 50 ppm und 1 Gew.-% S. Die Nachweisgrenze liegt bei 90 bzw. 45 ppm, je nach verwendetem Kristall. Bei annähernd übereinstimmender Matrix von Standard- und Analysenprobe ist eine rechnerische Matrixkorrektur nicht erforderlich.

     

Calculation of the real PCB content in environmental samples

Summary All individual polychlorinated biphenyls (PCB's) present in human milk and in butter were quantified. For calibration, a technical PCB mixture of known composition was used. The real total PCB concentration was determined by the addition of concentrations of the individual components. In human milk the calculated content was 50% and in butter 40% lower than values obtained by the usual calculation based on evaluation of some higher peaks of technical PCB mixtures.In addition, the approximate metabolization rates of the individual PCB components were calculated by comparison with the pattern of a technical PCB mixture (Clophen A 60).

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Berechnung der wahren PCB-Gehalte in UmweltprobenII. Ermittlung des PCB-Gehaltes von Frauenmilch und Butter

Zusammenfassung Sämtliche in Frauenmilch und in Butter vorkommenden Komponenten des Gemisches der polychlorierten Biphenyle (PCB) wurden quantitativ bestimmt. Die Eichung erfolgte dabei mit Hilfe eines technischen PCB-Gemisches von bekannter Zusammensetzung. Der wahre Gesamtgehalt an PCB, berechnet durch Addition der Einzelwerte war bei Frauenmilch um 50%, bei Butter 40% niedriger als die Konzentrationen, die sich nach der sonst üblichen Berechnungsweise durch Bezug auf einige hohe Peaks technischer PCB-Gemische ergeben.Außerdem wurden die annähernden Abbauraten der einzelnen PCB-Komponenten im Vergleich zu einem technischen PCB-Gemisch (Clophen A 60) berechnet.

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Dedicated to Prof. Dr. L. Acker on the occasion of his 70th birthday

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Part I: Fresenius Z Anal Chem 314:545 (1983)     

Precise simultaneous determination of zirconium and hafnium in silicate rocks,meteorites and lunar samples

A precise, sensitive and rapid analytical technique has been developed for the simultaneous determination of Zr and Hf in natural silicate matrices. The technique is based on radiochemical neutron activation analysis and employs a rapid fusion dissolution of the sample and simultaneous precipitation of the Zr−Hf pair with p-hydroxybenzene arsonic acid in an acidic medium. The indicator radionuclides,⁹⁵Zr and¹⁸¹Hf, are counted with a pair of high resolution Ge(Li) detectors and the⁹⁵Zr activity is corrected for the contribution from U fission. The chemical yields of the radiochemical separation are based on Hf carrier, which quantitatively carries both Zr and Hf. The yield is determined by reactivation of the processed samples and standards with a²⁵²Cf isotopic neutron source and by counting the 18.6 sec half-life^179mHf. The sensitivity, precision and accuracy of the procedure are demonstrated by replicate analyses of several standard rocks, meteorites and lunar samples which exhibit a wide range of Zr and Hf abundances.     

Calibration strategies for quantifying the Mn content of tooth and bone samples by LA-ICP-MS

There is a growing interest in using biomonitoring of tooth and bone specimens to assess human exposure to manganese (Mn). Information on historical exposure to Mn can be obtained through micro-spatial analysis of such specimens by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The principal aim of this study was to compare several calibration strategies for determining Mn content in tooth and bone by LA-ICP-MS including: (a) a six-point calibration curve based on synthesized hydroxyapatite (HA) materials, and single-point calibrations based on (b) NIST SRM 1400 Bone Ash, (c) NIST SRM 1486 Bone Meal, and (d) NIST SRM 612 Trace Elements in Glass. Performance was similar between different ICP-MS platforms (quadrupole ICP-MS, dynamic reaction cell ICP-MS, and sector field ICP-MS). Data based on calibration using the ⁵⁵Mn count rate were compared to that based on using the ⁵⁵Mn/⁴³Ca count rate ratio to obtain results as the Mn mass fraction. Reasonable performance was obtained by calibration using either SRM 612 or SRM 1400, in combination with the ⁵⁵Mn/⁴³Ca count rate ratio and using either the synthesized HA standards or SRM 1400 as calibrators, combined with ⁵⁵Mn count rate. By contrast, calibration based on SRM 1486 resulted in a systematic low bias. While there are several options for quantifying the Mn content of tooth and bone using LA-ICP-MS, users should be aware of the potential for strong matrix effects that may affect results. Overall, determining the ⁵⁵Mn/⁴³Ca count rate ratio, rather than the mass fraction, may represent a better approach for reporting the content of Mn in tooth and bone by LA-ICP-MS.     

Determination of hafnium in zircaloy clad by means of INAA

Three reactions are described for the analysis of small concentration of Hf in zircaloy clads used for BWR and PWR reactor. One of the measurements is based on the measurement of short-lived^179mHf /18.7 sec/. The method is fast, selective, highly sensitive, non-destructive and has a detection limit of 1.3 ng for Hf.     

Determination of sulphur content in drill core samples by backscattered beta-particles and gamma-ray absorption

A relatively simple method of sulphur determination in drill cores of calcium carbonate matrix is described. The method is based on the combination of measurements of backscattered beta-particles and transmitted low energy gamma-radiation intensities. The transmitted gamma-radiation measurement corrects the errors of sulphur determination caused by the varying strontium sulphate and silicon dioxide content. The method has been tested on 170 samples. It was estimated that the standard deviation of sulphur determination does not exceed 2.5% of sulphur. The apparatus for routine absorption measurement is also described.     

X-ray determination of traces of hafnium in zirconium metal or traces of zirconium in hafnium metal after separation by ion exchange

A method is proposed for the determination of traces of hafnium in zirconium metal or zirconium in hafnium metal. The trace metals are first separated from the matrix metals on an ion-exchange column and then determined by X-ray analysis.     

Direct analysis of inorganic anions in samples with high salt content by capillary zone electrophoresis

Trace-level inorganic anions in seawater are separated efficiently by capillary zone electrophoresis using direct UV detection. The carrier electrolyte is 50 mM borate at pH 9.3 and contained 1.5M NaCl. This buffer solution is adopted to prevent interference from high concentrations of the chloride ion in seawater. No electro-osmotic flow reverser is used to shorten the analysis time. The experimental conditions such as the concentration of NaCl in the carrier electrolyte, capillary inner diameter, applied current, and temperature are optimized. Linear plots are obtained in the concentration range of 0.1 to 20 microg/mL. The quantitation limits of the anions are in the order of 0.02 to 0.1 microg/mL. The proposed method may be applicable to the determination of inorganic anions in other environmental samples and effluents of a power plant.     

Internal correction of hafnium oxide spectral interferences and mass bias in the determination of platinum in environmental samples using isotope dilution analysis

A method has been developed for the accurate determination of platinum by isotope dilution analysis, using enriched ¹⁹⁴Pt, in environmental samples containing comparatively high levels of hafnium without any chemical separation. The method is based on the computation of the contribution of hafnium oxide as an independent factor in the observed isotope pattern of platinum in the spiked sample. Under these conditions, the ratio of molar fractions between natural abundance and isotopically enriched platinum was independent of the amount of hafnium present in the sample. Additionally, mass bias was corrected by an internal procedure in which the regression variance was minimised. This was possible as the mass bias factor for hafnium oxide was very close to that of platinum. The final procedure required the measurement of three platinum isotope ratios (192/194, 195/194 and 196/194) to calculate the concentration of platinum in the sample. The methodology has been validated using the reference material “BCR-723 road dust” and has been applied to different environmental matrices (road dust, air particles, bulk wet deposition and epiphytic lichens) collected in the Aspe Valley (Pyrenees Mountains). A full uncertainty budget, using Kragten’s spreadsheet method, showed that the total uncertainty was limited only by the uncertainty in the measured isotope ratios and not by the uncertainties of the isotopic composition of platinum and hafnium. Figure Simultaneous correction of hafnium oxide spectral interferences and mass bias in the determination of platinum in environmental samples using isotope dilution analysis Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

顺序注射光度滴定法测定食醋和饮料的总酸度

以溴百里酚蓝(BTB)为指示剂,NaOH溶液(含指示剂)为滴定剂,应用顺序注射光度滴定法测定了食醋和饮料的总酸度。乙酸在0.20～2.00mol/L、柠檬酸在3.29×10-3～1.67×10-2mol/L范围内其浓度的对数分别与(未反应碱区带的)吸收信号的峰面积成反比例关系,测定方法的相对标准偏差(RSD)分别为HAc<3.0%、柠檬酸<1.3%,采样频率为30样/h,对市售食醋及饮料样品检测的结果与国家标准方法(酸碱滴定法)一致。     

Study of mixed chelates of hafnium by solvent extraction

The extraction of mixed chelates of hafnium using furoyltrifluoroacetone and thenoyltrifluoroacetone has been studied from chloroform, toluene and carbon tetrachloride media. Equilibrium constants as well as stabilisation constants have been calculated. An attempt has been made to interpret the data on the basis of regular solution theory.     

Solvent extraction of hafnium(IV) by N-benzoyl-N-phenylhydroxylamine

The extraction of hafnium(IV) tracer by N-benzoyl-n-phenylhydroxylamine (BPHA) from 1M perchloric acid has been investigated and stability constants have been calculated for the complexes Hf(BPHA)(i)((4-i)+) (i = 1cdots, three dots, centered4). It was found that variation of perchlorate concentration in the range 0.5-2.0M at constant acidity has no effect on the distribution of hafnium.     

Determination of zirconium and hafnium in solution by X-ray fluorescence spectrometry

The samples were introduced into the XRF spectrometer in ordinary flat bottom polyethylene bottles for the estimation of Zr or Hf in presence of one another in solution. By using high voltage (50 kV) and high current (50 mA) least limits of detection obtained were an order of magnitude better than other conventional analytical techniques. Relations of intensity to concentration in various concentration ranges have been determined and the results are compared with those of other analytical techniques.     

Determination of microelement content in the samples from the cycle of intensive poultry breeding

The results of analysis of 15 samples of meat, eggs, feed and water used in the cycle of intensive poultry breeding are given in the paper. Twenty chemical elements such as: Sm, Lu, Eu, Hf, Ce, Yb, Cr, La, Br, Sb, Cs, Sc, Fe, Co, Na, Ta, Tb, Zr, Rb and Zn have been quantitatively determined in all the samples by nondestructive neutron activation analysis. Qualitative determination of K, Ca, Ru and Au was also performed in some samples.