Direct Current Plasma Emission Spectrometry Research Articles

Selective Dissolution of Electrodeposited Zn-Ni Alloy Coatings

SUMMARYThe corrosion of Zn-Ni alloy coatings in pure and NaHCO, containing Nad solutions was investigated under open circuit potential conditions. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques were applied for the alloy surface characterisation, while direct current plasma emission spectrometry was used for test solution and corrosion product film analysis. It has been established that Zn dissolves preferentially leaving a top layer slightly enriched with Ni. However, this layer does not act as a barrier layer for the further corrosion attack. The presence of NaHCO3, in NaC! solution causes a reduction in the corrosion rales of Zn-Ni alloy and the thickness of corrosion product (oxide) film, as well as affecting the ratio of the soluble and insoluble fractions of ionised Zn and Ni and the development of the surface morphology. In a pure NaCl solution Zn-Ni corrosion occurred with surface roughening, while in the presence of NaHCO3 the process was accompanied by surface smoothing.

Silicon assays in women with and without silicone gel breast implants--a review.

During the past 5 years, as the failure properties of silicone gel breast implants have emerged, there has been considerable interest in measuring the levels of silicone and silicon in blood, serum, breast milk, and body tissues. Assays have been done in control patients without implant exposure, and in patients with silicone gel implants in an attempt to predict implant failure. Nuclear magnetic resonance measurements of silicone compounds have not been helpful because of their low sensitivity of detection. However, all compounds containing the element silicon, which includes silicone, have been measured accurately. Modern techniques, such as electrothermal atomic absorption spectrometry, direct-current plasma emission spectrometry, and inductively coupled plasma emission spectroscopy have allowed precise measurement of silicon in body fluids and tissues. Using these techniques, recent studies have demonstrated consistent levels of silicon in the blood and plasma of control women without exposure to implants. In one study, plasma silicon was shown to be 140 +/- 10 ng per milliliter. In four other studies, serum silicon levels in control patients were the following: mean, 130 +/- 70 ng per milliliter; mean, 170 +/- 100 ng per milliliter; median, 100 ng per milliliter (range, 30-209 ng per milliliter); and 10 to 250 ng per milliliter. Three independent studies have shown that women with silicone gel implants have higher blood and serum silicon levels than control subjects, but their values were still within the range of control subjects. One study has shown that the mean silicon level in breast milk was not significantly different between 15 implant patients and 34 control patients. The measurement of silicon in control breast tissue has shown consistent results in three different studies, with most tests varying from <0.2 to 2.2 microg per gram dry weight. Three studies have shown that capsules from women with silicone gel breast implants had markedly elevated silicon levels compared with control breast tissue. Median silicon levels varied from 9,980 to 14,390 microg per gram dry weight. There was no significant difference in capsule silicon level between intact and ruptured implants or associated with implant duration in situ or year of implantation. Four studies have shown that capsules from saline implants had elevated levels of silicon compared with control tissue, but their silicon levels were much lower than those of gel implants. The median levels of silicon in the capsules of these studies were as follows: 7.7, 71.5, 198, and 1,100 microg per gram dry weight. Based on current knowledge, because of the large variability among patients, the use of silicon measurements in blood, serum, breast milk, or implant capsule tissue has no clinical role for the effective monitoring of implant leakage in women with silicone gel breast implants.

Observations on Determination of Dysprosium in Labeled Digesta Samples by Near Infrared Spectroscopy

The objective of this work was to determine whether the Dy content of ruminal digesta samples labeled by pulsedosing intra-ruminally with Dy-labeled forages could be determined by near infrared reflectance spectroscopy. Ruminal grab samples were obtained from four steers. Equal numbers of alfalfa and orchardgrass samples were collected at 17 times (0 to 165h) after dosing and analyzed (total of 272 samples). Dysprosium was determined by direct current plasma emission spectrometry. Spectra were obtained by scanning ground samples on a scanning monochromator. Calibrations for Dy (0 to 349.5ppm; mean = 44.5ppm) were carried out using both step-wise and partial least squares regressions. Wavelength selections using step-wise regression included characteristic Dy wavelengths and resulted in R2 and standard error of analysis of ∼.9 and ≥20ppm, respectively. Partial least squares regressions, although more robust, were not significantly better. Sample ashing to increase relative Dy concentrations did not improve the results. Further investigations indicated that interference by Co marker, also present in the samples, was a problem. Although near infrared reflectance spectroscopy is capable of determining Dy in labeled forages, further work is needed to increase its accuracy.

Determination of boron in high-purity silica using direct current plasma emission spectrometry

The method involves decomposition with hydrofluoric acid-nitric acid in the presence of mannitol in a simple closed Teflon PFA vessel and subsequent evaporation of silica without detectable losses of boron. The boron is determined by direct current plasma emission spectrometry. The detection limit is 0.76μg g −1. The possible losses of boron resulting from evaporation of the solution to dryness were investigated.

Silicon measurement in serum and urine by direct current plasma emission spectrometry

Elemental silicon, present as soluble silicic acid in serum and urine, has been measured by direct current plasma emission spectrometry. The method is precise and accurate, yields a standard curve that is linear up to 1000 mumol/L, and requires only a simple dilution in 10 mL/L HNO3. No spectral or background interferences have been observed from serum or urine; the absolute detection limit for silicon was 0.5 mumol/L. Silicon concentrations in serum increase by up to 20-fold in patients with chronic renal failure on hemodialysis, an increase apparently related to dietary silicon intake. No relationship with aluminum was observed in hemodialysis patients, with or without aluminum toxicity. In the undialyzed patient with chronic renal failure, the concentrations of silicon in plasma increased with decreasing glomerular filtration rate. This increase may protect renal-failure patients from possible aluminum toxicity by promoting formation of the relatively inactive aluminosilicate complex. Silicon concentrations in urine of healthy individuals exceed their serum concentrations by 20- to 100-fold. Silicon excretion in patients with renal stones was not different from that in healthy controls and showed no relationship with calcium and (or) oxalate excretion.

A Simple Purge System for Determination of Sulfur Using the Direct-Current Plasma

A significant limitation to the use of the direct-current plasma (DCP), for sulfur analysis is the inability of the echelle spectrometer system to operate effectively at wavelengths below 190 nm. This difficulty arises because the spectrometer is not calibrated below 190 nm, and because the intensities of these short wavelengths are severely attenuated by the echelle's prism. For these reasons, the determination of sulfur, which has strong emission in the 180–183 nm region, is not routinely performed by DCP emission spectrometry.

Quantification of toxic-chemicals in selected human-populations

the pg/mL range with in-line preconcentration [5]. During the development of this method at NBS, the factors investigated included: composition of the eluents, interference due to impurities in the delivery liquid and the possible means of eliminating them with a laboratory-packed trap column, and a comparison of suppression efficiencies between two types of suppressors. This method was used for the determination of Mg2 and Ca2 in SRM 2694, Simulated Rainwater, with precisions and accuracies better than 2% relative [5]. The frontier for ion chromatography is transition metal analysis with ongoing research along many fronts. New resins are being introduced and are being coupled to exotic detectors. The era of hyphenated techniques is burgeoning with ion chromatography showing up as the front-end separation method of choice. Recent work at NBS has coupled ion chromatography with direct current plasma emission spectrometry for the determination of phosphorus in copper-based alloys [6]. Future challenges for ion chromatography will be to enhance further its capabilities through improved speed, sensitivity, and resolution. Speciation of metals as a function of oxidation state and complexation will be an important goal. Innovative resins and a new generation of detectors will have to be developed. Fundamental research into the retention mechanisms leading to the separation will be essential. In conclusion, ion chromatography has proven itself an invaluable tool to analytical chemistry. Its ultimate advantages will lie in its versatility and its capacity for ultra-trace analyses with minimal contamination and total automation.

Determination of phosphorus in copper-based alloys using ion-exchange chromatography and direct-current plasma emission spectrometry

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of phosphorus in copper-based alloys using ion-exchange chromatography and direct-current plasma emission spectrometryM. S. Epstein, W. F. Koch, K. S. Epler, and T. C. O'HaverCite this: Anal. Chem. 1987, 59, 24, 2872–2876Publication Date (Print):December 15, 1987Publication History Published online1 May 2002Published inissue 15 December 1987https://doi.org/10.1021/ac00151a009RIGHTS & PERMISSIONSArticle Views53Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (664 KB) Get e-Alerts Get e-Alerts

The determination of samarium, europium, gadolinium and dysprosium in uranium products by direct-current plasma emission spectrometry

Samarium, europium, gadolinium and dysprosium were separated from uranium-containing materials by means of solvent extraction with Alamine 336, followed by cation-exchange. The elements were determined in the sub-ppm range by means of direct-current plasma atomic-emission spectrometry.

Determination of trace amounts of molybdenum in plant tissue by solvent extraction-atomic-absorption and direct-current plasma emission spectrometry

Methods are presented for determination of molybdenum in plant tissue by flame and graphite-furnace atomic-absorption spectrometry and direct-current argon-plasma emission spectrometry. The samples are digested in HNO 3-H 2SO 4-HC1O 4 mixture, and Mo is separated and concentrated by chelation and extraction. Three organic solvents (methyl isobutyl ketone, di-isobutyl ketone and isoamyl alcohol) and two ligands (8-hydroxyquinoline and toluene-3,4-dithiol) were studied. The procedure were tested on pine needle and birch leaf samples.

Comparison of three techniques to determine al content in micro‐samples of plant material

Abstract Comparisons are made of three methods of Al analysis in micro‐samples (≤ 100 mg) of plant material. Direct current plasma emission spectrometry (DCP), graphite furnace atomic absorption spectrometry (GFAAS), and pyrocatechol violet (PCV) all gave comparable results for the plant materials analyzed. The importance of adequate sample dissolution of digested samples prior to analysis by PCV was strikingly apparent. Our results indicate that to insure complete formation of reactive Al species to complex with the dye that a combination of 12 N HCl and a 1 hr heat treatment at 70°C in a steam bath is necessary. Residue decomposition of materials with HF acid resulted in more apparent Al only by DCP analysis. Contribution of the residue to the total Al content varied between 7 and 14%.

Enhancement Errors in the Determination of Platinum Group Metals in Alumina-Based Matrices by Direct-Current Plasma Emission Spectrometry

Direct-current plasma emission spectrometric analysis of platinum group metals in solutions from automobile catalyst shows significant enhancement of analyte values Addition of a lithium buffer does not remove the interference The only matrix constituents in these solutions were aluminum and magnesium, both of which were found to cause enhancement in the determination of platinum, palladium, and rhodium A buffer consisting of 3500 mg/L lithium and 2500 mg/L lanthanum removed the enhancement effect of both magnesium and aluminum on these metals 8-hydroxyquinoline also reduced the degree of interference due to aluminum, although not as efficiently as lanthanum, indicating that formation of compounds in the dc plasma is a possible source for the observed interference

Plasma emission spectrometry: measurement of calcium, phosphorus and chromium in metabolic balance studies.

Direct-current plasma emission spectrometry determines food calcium and phosphorus, faecal calcium and chromium, and urinary calcium and phosphorus accurately, precisely and rapidly without acid digestion or dry ashing. Food and faeces are homogenised, diluted and aspirated directly into the plasma. The method makes metabolic balances swifter and less labour-intensive; it enables the use of chromium sesquioxide as an inert marker, for perchlorate digestion is avoided. Both plasma emission (-9.9%) and a dry ashing procedure (-13.5%) give lower values for food phosphorus than those derived from food tables.

Chemical composition of Piceaabies and Pinussylvestris seeds under subarctic conditions

Seeds produced by 50 Piceaabies L. and 50 Pinussylvestris L. trees near the timberline in eastern Finnish Forest Lapland were collected in late winter 1973–1981, counted, and analysed chemically (specially developed procedure with direct-current plasma emission spectrometry (DCP-AES)). Seed yields, their 1000-grain weights, and their quality varied considerably from year to year in both species, P. abies having good seed yields less often than P. sylvestris (only one good yield during the study period). The mean number of seeds produced by P. abies correlated positively with their 1000-grain weights; in P. sylvestris it did not. The nitrogen, crude fat, sugar, phosphorus, and magnesium contents correlated positively with the corresponding 1000-grain weights, suggesting that these constituents occur mainly in the endosperm and (or) embryo(s) of a seed. The crude fibre and calcium contents, however, correlated negatively with the 1000-grain weights, implying that they occur mainly in the testa. The sodium content did not increase or decrease with increasing 1000-grain weight. The composition of seeds with the same 1000-grain weight but representing yields of different years might also vary. The crude protein proportion in the P. abies seeds produced in different years varied from 9.4 to 19.3%, crude fat varied from 11.0 to 40.2%, and phosphorus varied from 0.30 to 0.83%; the corresponding ranges for P. sylvestris seeds were 10.9–30.9, 7.2–33.5, and 0.42–0.98%, respectively. Some aspects of defensive strategies of sympatric pine and spruce stands under hostile conditions at the timberline are discussed.

Elemental analysis of estuarine sediments by lithium metaborate fusion and direct current plasma emission spectrometry

Elemental analysis of estuarine sediments by lithium metaborate fusion and direct current plasma emission spectrometry

Application of atomic absorption and plasma emission spectrometry for environmental analysis

The application of flame atomic absorption (FAAS), electrotehrmal atomic absorption (ETAAS), inductively coupled plasma emission (ICP), and direct-current plasma emission spectrometry (DCP) for the determination of major, minor, and trace elements in Urban Particulates (SRM 1648), Wear Metals in Oil (SRM 1084 and 1085), and Simulated Solid-Waste Leachates is described. Interference were encountered in the determination of the trace elements in SRM 1648 by ETAAS; however, these interferences were alleviated using a 1% solution of ammonium dibasic phosphate as a matrix modifier. The concentration of elements in SRM 1084 and 1085 and the simulated solid-waste leachates were significantly above the detection limits by FAAS or ICP and no analytical difficulty was encountered.

Determination of boron in glass by direct current plasma emission spectrometry

Determination of boron in glass by direct current plasma emission spectrometry