The determination of mercury by non-flame atomic absorption and fluorescence spectrometry.

An isotopic dilution method has been developed for the determination of ²²⁶Ra and ²²⁸Ra in sea water and sediments with ²²³Ra as a yield tracer. An alternative procedure which obviates the need for ²²³Ra is demonstrated for sediments by the assay of ²²⁴Ra and ²²⁸Th which occur naturally in sediments. In addition, a direct method for β-counting ²²⁸Ra–²²⁸Ac is proposed. Radium, polonium, thorium and uranium isotopes and ²¹⁰Pb are coprecipitated from sea water with aluminum phosphate carrier. The radium and lead-210 are coprecipitated with lead nitrate in sediment leachings. All radium procedures utilize identical chemical isolation and the cathodic electrodeposition of radium. Subsequently, the α-radiation emitted by ²²⁶Ra, ²²³Ra and ²²⁴Ra is determined by pulse-height analysis: the ²²⁸Ra-²²⁸Ac and ²¹⁰Pb-²¹⁰Bi are measured by low background anticoincidence β-counting techniques. This method was used for samples containing 10^-11–0.5 · 10^-12 g of ²²⁶Ra and 10^-13–10^-15 g of ²²⁸Ra and gave a precision of 3–6% and 5–10% respectively, even though radium levels an order of magnitude less can be measured. The ²²⁶Ra method is applicable to all environmental samples, whereas ²²⁸Ra determinations are limited to applications where the ${}^{228}\text{Ra}{}^{226}\text{Ra}$ activity ratio is greater than 0.1. This method is especially attractive for studies of parent-daughter disequilibria.     

Improvements in the non-flame atomic fluorescence determination of mercury

A new non-flame atomic fluorescence system with a detection limit of 5 parts per trillion (p.p.t.) or 5 pg of mercury(II) has been developed. The relative precision is 5% or better above 50 p.p.t. Hg(II), and the dynamic range in terms of linearity is from 0–100 p.p.b. Hg(II). The system is useful for analysis of residual mercury levels in water at a rate of about thirty samples per h.     

Comparative study for aluminum determination in bone by atomic absorption techniques and inductively coupled plasma atomic emission spectroscopy

A comparative investigation was carried out on the suitability of atomic absorption spectrometry and inductively coupled plasma atomic emission spectroscopy for aluminum determination in bone. Both techniques give reliable results but the nitrous oxide-acetylene flame method was not found to be sensitive enough to accurately measure low aluminum content. A suitable method for sample treatment is also described. Quantitation of aluminum in bone from patients on regular hemodialysis is also done.     

Automated sample preparation for X-ray fluorescence, plasma emission and atomic absorption spectrometry

Summary There exists an important disparity between the high throughput of modern spectrometers for the analysis of mineral products and the weak means for the isoformation of samples. To fill this gap the French Iron and Steel Research Institute (IRSID), with the financial help of the European Community for Steel and Coal, has developed several instruments able to rapidly prepare samples for X-ray fluorescence, plasma emission and atomic absorption spectrometries. These three devices are able to prepare beads, solutions or both. Using high frequency heating, effective mixing during the fusion-dissolution process as well as a judicious choise of a number of parameters. The samples obtained are of such a quality that the preparation and measurement reproducibilities are often very similar.

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Automatische Probenvorbereitung für die Röntgenfluorescenz-, Plasmaemissions- und Atomabsorptions-SpektrometrieProbenvorbereitung mittels PERL'X-2, PLASMASOL und SOL'X

Zusammenfassung Es besteht eine große Ungleichheit zwischen dem hohen Probendurchsatz der modernen Spektrometer zur Analyse anorganischer Produkte und den unzureichenden Mitteln der Probenaufbereitung. Aus diesem Grund hat das französische Forschungsinstitut für Eisenhüttenwesen (IRSID) mit der finanziellen Hilfe der Europäischen Gemeinschaft für Kohle und Stahl einige Geräte entwickelt, die es erlauben, schnell Proben für die Röntgenfluorescenz, die mit Plasma angeregte optische Emission und die Atomabsorption aufzubereiten. Diese drei Geräte können Perlen, Lösungen, oder beide zugleich herstellen. Dank einer Hochfrequenzheizung, einer guten Durchmischung während der Aufschmelzung-Verdünnung und gezielt gewählter Parameter sind die erhaltenen Proben von einer solchen Qualität, daß die Reproduzierbarkeit von Aufbereitung und Messung in vielen Fällen nahezu gleich ist.

     

A comparative study of radioactivation,atomic absorption and spectrophotometric techniques applied to the determination of mercury in lead

A fairly simple radiometric method has been developed for the quantitation of microgram amounts of mercury in lead samples of different purity grades. It is mainly based on 3 steps; (i) the removal of most interfering cations with ferric hydroxide scavenger in the presence of a suitable masking agent, (ii) the separation of mercury as hydrated mercuric oxide from a highly alkaline medium, (iii) its distillation as mercuric chloride followed by precipitation as the sulfide. The method is reproducible and the results which show, in general, a standard deviation of ±4.29% are compared with those obtained by atomic absorption (4.48%) and spectrophotometric (13.13%) techniques.     

Evaluation of the solid sampling technique for the determination of aluminium in biological materials by atomic absorption and atomic emission spectrometry

Summary Results for the determination of aluminium in several biological materials by atomic absorption and atomic emission spectrometry using the solid sampling technique in connection with a constant temperature furnace are given. A comparison was made with a dissolution procedure and good agreement was generally obtained. With the solid sampling technique it was possible to calibrate against aqueous standards and to achieve a precision of better than 10% r.s.d. for NBS 1577a Bovine Liver and IAEA H-4 Animal Muscle, providing that the sample mass was greater than 1.3 mg and that the peak area was evaluated. Laboratory air and the solid sampling procedure were identified as possible sources of contamination.

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Auswertung der Feststofftechnik für die Bestimmung von Aluminium in biologischen Materialien durch AAS und AES

     

A sequential injection cold-vapor atomic absorption method for the determination of total mercury

A sequential injection (SI) method for the determination of mercury via cold vapor atomic absorption spectrophotometry is presented. The method differs from flow injection (FI) cold vapor methods for the determination of mercury because of the simplicity of the system required for the method: one pump, one valve, a gas-liquid separator, and an atomic absorption spectrophotometer equipped with a quartz cell. Under optimal conditions, the method has the following figures of merit: a linear calibration range of 1.0 to 20 microg L(-1); a detection limit of 0.46 microg L(-1); and a precision of 0.90% RSD (8 microg L(-1)). The procedure allows for a sampling rate of one injection per 80 s (excluding sample pretreatment). Results from the determination of mercury in water and fish specimens are also presented. The figures of merit of the method are compared to two other SI methods for the determination of mercury.     

A sequential injection cold-vapor atomic absorption method for the determination of total mercury

A sequential injection (SI) method for the determination of mercury via cold vapor atomic absorption spectrophotometry is presented. The method differs from flow injection (FI) cold vapor methods for the determination of mercury because of the simplicity of the system required for the method: one pump, one valve, a gas-liquid separator, and an atomic absorption spectrophotometer equipped with a quartz cell. Under optimal conditions, the method has the following figures of merit: a linear ¶calibration range of 1.0 to 20 μg L^–1; a detection limit of 0.46 μg L^–1; and a precision of 0.90% RSD (8 μg L^–1). The procedure allows for a sampling rate of one injection per 80 s (excluding sample pretreatment). Results from the determination of mercury in water and fish specimens are also presented. The figures of merit of the method are compared to two other SI methods for the determination of mercury.     

Liquid chromatographic--cold vapour atomic fluorescence spectrometric determination of mercury species

Solvent extraction, sonication, and microwave-assisted extractions in the presence of extraction agents (thioacetic acid, citric acid, cysteine, 2-mercaptoethanol, HCl + NaCl, etc.) were tested for the isolation of mercury species. A mixture of 6 M HCl and 0.1 M NaCl was selected as the most suitable extraction agent. The extraction efficiency was about 10% higher and the RSD below 3.3% when microwave-assisted extraction was applied instead of sonication. The liquid chromatography-cold vapour atomic fluorescence spectrometry (LC/CV-AFS) method was optimised and used for separation and determination of inorganic mercury cations and alkylated and arylated mercury species. Isocratic elution at a flow rate of 0.15 mL/min (with a mobile phase containing 0.05% 2-mercaptoethanol (pH = 5) and 7% methanol and with a stepwise increase of methanol content up to 100% MeOH in the 15th min) was used for separation of mercury species on a Hypersil BDS C18 RP column. The limits of detection of the LC/CV-AFS system were estimated as 0.2 microg/L (3%) for MeHg+, 0.07 microg/L (5.3%) for inorganic Hg, 0.06 microg/L (3.4%) for PhHg+, and 0.12 microg/L (4.4%) for EtHg with the corresponding RSDs at 5 microg/L (n = 10) given in parentheses. The concentrations (2-10 mg/kg fresh weight) of total mercury and methylmercury (90-99% of the total mercury) in selected fish obtained by HPLC/CV-AFS were in good agreement (absolute deviations 0.05 mg/kg) but more precise (RSDs <5.4% at 5 mg/L, n = 10) than those determined by GC coupled to an electron capture detector. The RSDs (3.1-8.2% and 4.1-9.0%) of the overall analytical procedure for the determination of total mercury (AMA 254) and methylmercury (HPLC/CV-AFS) were determined for intra-day and inter-day assays, respectively.     

Tungsten coil devices in atomic spectrometry: absorption, fluorescence, and emission.

In this work, tungsten coil (W-Coil) devices are used as atomizers for electrothermal atomization atomic absorption spectrometry (ETAAS), electrothermal atomization laser excited atomic fluorescence spectrometry (ETA-LEAFS), and electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES). For most cases in ETAAS and ETA-LEAFS, limits of detection (LODs) using the W-Coil are within a factor of ten of those observed with commercial graphite furnace systems. LOD for Cd by W-Coil AAS is 10 pg, while LODs for As, Se, Cr, Sb and Pb by W-Coil LEAFS are 950, 320, 1400, 330, and 160 fg, respectively. The compact W-Coil device makes it an ideal atomizer for portable atomic spectrometry instrumentation, especially when coupled with a miniature charge coupled device spectrometer. Alternatively, the atomizer can be used as an inexpensive, modular add-on to an existing commercial ICP-AES system; and the thermal separation of Pb with interference elements Al, Mn, and Fe is demonstrated.     

Comparative determinations of lead in soils by X-ray fluorescence, atomic absorption spectrometry, and atomic emission spectrometry

Summary Determinations of lead in different soil samples were carried out by X-ray fluorescence (XRF) (borate-glass fusion 13), atomic absorption spectrometry (AAS), and induced coupled plasma atomic emission spectrometry (ICP-AES) (aqua regia digestion). The concentration ranges in contaminated soils were 10 to 200 wt. ppm and 0.05 to 3.0 wt.%. The detection limit of XRF (5 ppm) is adequate; the precision of AAS (1%) is the best; but the relative accuracy of all three methods does not surpass 10%. This is because of errors in sampling and sample preparation, the latter being difficult to judge. Determinations with different methods and correlation analysis of the results are necessary.

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Vergleichende Bestimmung von Blei in Böden durch Röntgenfluorescenz, AAS und AES

Zusammenfassung Bleibestimmungen in verschiedenen Bodenproben wurden mit der RFA (Boratglas-Schmelze 13), AAS (Königswasser-Aufschluß) und ICP-AES (Königswasser-Aufschluß) durchgeführt. Die Konzentrationsbereiche waren 10 bis 200 Gew.-ppm und 0,05 bis 3,0 Gew.-% in kontaminierten Bodenproben. Die Nachweisgrenze der RFA (5 ppm) ist ausreichend; die Reproduzierbarkeit der AAS (1 %) ist die beste, aber die Richtigkeit der drei Methoden ist nicht besser als 10% relativ. Gründe dafür sind Fehler bei der Probenahme und bei der Probenvorbereitung; letztere sind schwer zu erkennen. Bestimmungen mit mehreren Methoden und Korrelationsanalyse der Resultate sind notwendig.

     

Simultaneous determination of arsenic, selenium, tin and mercury by non-dispersive atomic fluorescence spectrometry

A procedure is described for simultaneous determination of arsenic, selenium, tin and mercury in aqueous solution by non-dispersive atomic-fluorescence spectrometry. Radiofrequency-excited EDLs, 100% modulated in the kHz region, were used for atom excitation. Sodium tetrahydroborate was used as reductant and a hydrogen-argon miniflame as atomizer. In the optimized procedure, which uses 1 ml of sample, the limits of detection (three times the standard deviation of the blank) were 0.04, 0.08, 0.1 and 0.1 ng ml for arsenic, selenium, tin and mercury respectively. The linear dynamic range was greater than three decades for all analytes and the precision was better than 7% (typically 3%) for concentrations 1 ng ml . Results for mutual interference effects are reported. Copper, nickel, lead and cobalt interfered only with selenium (5 ng ml ), when present in at least 200-fold weight ratio to it. Using 5 ml of sample improved the limits of detection for selenium and arsenic (0.01 and 0.02 ng ml respectively), but at the expense of greater interference. Recovery from spiked natural water samples was better than 95% at the ng ml level, except for selenium in sea-water, when the recovery was only 85%. Determination of the four elements, including standard-addition and background measurements, requires about 10 min.     

A comparison of potentiometric,spectrophotometric and atomic absorption spectrometric methods for the determination of mercury in wastes

The potentiometric titration with dithiooxamide applied to mercury determinations in industrial wastes is compared with cold-vapour atomic absorption spectrometry and spectrophotometry with dithizone. The potentiometric method is shown to have adequate sensitivity and selectivity as well as economic advantages.     

The determination of mercury in air samples by flameless atomic absorption

A method is described for the determination of mercury in air by furnace atomic absorption. The porous graphite cups used ordinarily fail to adsorb mercury vapors from the air. When these same porous graphite cups are plated on the inner surface with a thin layer of gold the retention of mercury from an air sample passed through the cup is shown to be quantitative. The sensitivity of the analytical system is 3 × 10^?10 g which is equivalent to 0.6 $\text{μg}\text{m}{}^3$ for a 500 cm³ air sample. Relative S.D. is 11.2%. The method described should also prove useful for other types of flameless devices.     

Evaluation of new high-frequency discharge lamps for atomic absorption and atomic fluorescence spectrometry of cadmium,lead and zinc

High-frequency discharge lamps with a hollow electrode are successfully utilized as the spectral line sources for atomic absorption and atomic fluorescence spectrometry of cadmium, lead and zinc. The sensitivities for atomic absorption spectrometry are superior to those obtained with commercially available hollow-cathode lamps by factors of 1.5 (Cd), 1.4 (Pb) and l.6 (Zn). Detection limits for non-dispersive atomic fluorescence spectrometry with graphite furnace atomization are 1 × 10^-13 g (Cd), 3 × 10^-11 g (Pb) and 2 × 10^-13 g (Zn). The linear analytical range covers over four (Cd, Zn) and three (Pb) decades of concentration above the detection limits.     

Lead sulphide as a sorbent for the preconcentration of mercury from air and determination of mercury by atomic emission spectroscopy

Summary Lead sulphide, if prepared by precipitation reaction between lead acetate and sodium sulphide, both in aqueous solution, and adjusted to pH 1, has been shown to be an efficient absorbent for mercury vapour from air. After a portion has been used to collect mercury from a measured volume of air, it is packed into a hollow iron electrode and the mercury is determined by emission spectrography with a dc arc and photographic recording of the spectra from samples and standards. The limit of detection is about 0.1 g, and the relative standard deviation 9% at the 1 g level.

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Bleisulfid als Sorbent für die Anreicherung von Quecksilber aus Luft und Bestimmung von Quecksilber mittels Atomemissionsspektrographie

Zusammenfassung Bleisulfid, synthetisiert durch Fällungsreaktion zwischen wäßrigen Lösungen von Bleiacetat und Natriumsulfid (pH 1), erwies sich als sehr wirksames Adsorptionsmittel für Quecksilberdampf aus Luft. Der Kollektor, der eine bestimme Menge Quecksilber aus einem bekannten Volumen absorbiert hat, wird in eine Eisenhohlelektrode eingebracht und das Quecksilber durch Emissions-spektrographie (Gleichstrombogen, photografische Registrierung der Spektren) von Proben und Standards bestimmt. Die Nachweisgrenze liegt bei ungefähr 0,1 g und die relative Standardabweichung beträgt 9% bei 1 g Quecksilber.

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Presented as a poster at Euroanalysis V, Cracow, August 26–31, 1984     

Indirect atomic absorption and atomic emission spectrometric determination of antazoline,hydralazine and amiloride hydrochlorides and quinine sulphate

Ion-association complexes of antazoline HCl [I], hydralazine HCl [II], amiloride HCl [III] and quinine sulphate [IV] with [Co(SCN)₄]^2– and [Co(NO₂)₆]^3– were precipitated and the excess unreacted cobalt complex was determined. A new method using atomic emission and atomic absorption spectrometry for the determination of the above drugs in pure solutions and pharmaceutical preparations is given. The drugs can be determined in the ranges 0.3–3.0, 0.19–1.96, 0.3–3.0, and 0.78–7.82 mg/25 ml solutions of I, II, III, and IV, respectively, with mean relative standard deviations of 0.65–2.03 % and recovery values of 95.76–101.2% indicating high precision and accuracy.     

A critical review of atomic absorption, spectrochemical, and x-ray fluorescence methods for the determination of the noble metals--II

The review is a continuation of the initial reviews and covers the period of abstracting up to and including April, 1967. Work on the atomic-absorption determination of noble metals is also included.