Flameless Atomic Absorption Method Research Articles

PROSPECTS FOR THE USE OF ORGANIC DRIED PHYSALIS IN THE PRODUCTION OF FLOUR CONFECTIONERY

The article examines the consumption properties and prospects of using dried organic physalis in the production of flour confectionery products. The research object is dried physalis TM “Navitas”. The energy value of this product is 110 kcal/100 g. The fat content is 1 g/100 g; carbohydrates – 20 g/100 g; proteins – 2 g/100 g. Using atomic absorption spectrophotometry on a C-115 PK atomic absorption spectrophotometer, it was established that the potassium content in 100 g of the product is 543 mg, the phosphorus content is 43 mg/100 g. The content of other trace elements is limited. Thus, 100 g of dried organic physalis satisfies the need for potassium per day by 23.16%. Among all vitamins, physalis contains the most vitamin C – 11.7 mg/100 g. Physalis meets the needs of vitamin C by 16.71% and vitamin PP – by 18.50%. Vitamins of group A and B in the product are contained in a limited amount. To study the content of toxic elements in the product, generally accepted methods were used: copper, zinc, lead and cadmium were determined by the atomic absorption method, arsenic by the colorimetric method, mercury by the flameless atomic absorption method. The level of all toxic elements is below the permissible limits. Cadmium was not detected in organic physalis. Such data may indicate the safety of the product. The author has developed a recipe for a new cake made from organic raw materials “Grechanyk”, which contains dried physalis at the rate of 54 kg/t of product. Further research will be aimed at studying the consumer properties of the developed product.

Measurement of endogenous lithium levels in serum and urine by electrothermal atomic absorption spectrometry: A method with potential clinical applications

A highly sensitive flameless atomic absorption method has been adapted for the determination of endogenous trace lithium levels in serum and urine. With ammonium nitrate as the only matrix modifier, serum levels of Li as low as 0.03 μmol/liter are measured accurately and there is no requirement for standard additions. The need for background correction during analysis was clearly established, and tungsten and Zeeman-effect background corrections were compared. The tungsten correction offered superior sensitivity and linearity of standards. Recoveries in urine and serum average 94.8 ± 7.7 and 95.3 ± 6.1% (±SD), respectively. The endogenous serum Li levels were 0.16 ± 0.08 μmol/liter for normal subjects dwelling in the Denver metropolitan area. The mean 24-h excretion rate was 5.24 ± 1.4 μmol/day. The mean fractional excretion of endogenous Li (clearance Li/clearance creatinine) was 23.2 ± 3.0%, a value similar to values published for exogenously administered Li and measured by conventional methods.

Nephrotoxic effect of gold sodium thiomalate in rats--ultrastructual observations using electronmicroscopy and X-ray energy dispersive analysis

The purpose of this study is to demonstrate renal injuries by gold sodium thiomalate (G) with ultrastructual changes and gold deposition in kidney tissue using X-ray energy dispersive analysis (XEDA). Twenty-five mg of G containing 12.1 mg of Au was injected into rats intraperitoneally. The rats were divided into 5 groups. Group 1 was sacrificed 6 hours after the injection of G, and group 2 after 24 hours, group 3 after 72 hours and group 4 after 144 hours. Group 5 consisted of the control-rats which were provided with injections of saline. Gold contents in kidneys, liver, lungs and spleen were measured using the flameless atomic absorption method. XEDA was also performed in order to confirm the gold deposition in tissue. Among the organs, only the kidney showed remarkable changes with increased weight. Group 1 already showed marked azotemia which reached to the maximum level in group 3. The amount of gold content in the organs did not change significantly in spite of a marked reduction of serum gold concentration among the 4 groups. Histological examinations revealed marked degeneration and necrosis of pars recta in proximal tubules, although no prominent abnormalities of glomeruli could be observed. Using an electron microscope, many electron dense particles in lysosome were noticed, mainly in proximal tubules. We also found these particles in lysosome of glomerular epithelial cells. Using XEDA, these electron dense particles were demonstrated to be gold, since characteristic energy of gold was found. In conclusion, the kidney was shown to be the most accumulative organ of gold. G caused acute extensive necrosis of proximal tubules. Gold was demonstrated as electron dense particles in lysosomes mainly in proximal tubules, but also partly in glomeruli. Therefore, it was confirmed that a large amount of G had a strong nephrotoxic effect in rats.

Regional distribution of lead, zinc, iron and copper in suckling and adult rat brains

The flameless atomic absorption method was applied to reveal regional differences in heavy metals between suckling and adult rat brains. The lead concentration in the suckling brains were considerably different from those in the adult rats. The levels of lead concentration in the cerebrum and cerebellum of the normal suckling rats were 3–4 times higher than those of adult rats. Iron concentrations in the cerebrum of the suckling brains were approximately half those in the adult brains. Zinc and copper concentrations in medulla from the suckling rats were higher than those in the same region from the adult rats.

Establishment of normal values in adults for zinc protoporphyrin (ZPP) using hematofluorometer: correlation with normal blood lead values.

Zinc protoporphyrin (ZPP) values were analyzed with a hematofluorometer on 395 non-occupationally lead exposed subjects. Blood lead (B-Pb) determinations were concurrently carried out with an extraction procedure using flameless atomic absorption method. Applying Hoffman's Statistical Analysis with a logarithmic transformation, a normal range for ZPP (a mean of 23 microgram/dL) was established with 40 microgram ZPP/dL on the upper limit of the 95% probability range. A value of 54 microgram ZPP/dL has been found to be a suitable cutoff value above which one generally finds B-Pb values greater than 40 microgram/dL. For B-Pb values (less than 40 microgram/dL) and ZPP values in our normal range, there was essentially no correlation. However, for elevated values of both, a correlation coefficient of 0.87 was found for log ZZP versus B-Pb. ZPP values for males appeared to increase with increasing age.

Flameless atomic-absorption determination of gold in geological materials

Abstract Gold in geologic material is dissolved using a solution of hydrobromic acid and bromine, extracted with methyl isobutyl ketone, and determined using an atomic-absorption spectrophotometer equipped with a graphite furnace atomizer. A comparison of results obtained by this flameless atomic-absorption method on U.S. Geological Survey reference rocks and geochemical samples with reported values and with results obtained by flame atomic-absorption shows that reasonable accuracy is achieved with improved precision. The sensitivity, accuracy, and precision of the method allows acquisition of data on the distribution of gold at or below its crustal abundance.

Flameless atomic-absorption determination of impurities in high-purity silver after extractive separation of the matrix

A flameless atomic-absorption method has been developed for analyzing high-purity silver for its As, Bi, Cd, Co, Cr, Cu, Fe, Ir, Mn, Mo, Ni, Pb, Pd, Rh, Sb, Se, Te and Zn content. Optimum determination conditions have been found for all these elements. A mutual effect of microelements has been studied; to eliminate this effect, buffering with copper sulphate (5 mg/ml) has been used. The effect of silver on the atomic absorption of the impurities has also been investigated. Extractive concentration of silver with O-isopropyl-N-methylthiocarbamine has been used to rule out the matrix effect and to reduce the detection limits. Palladium has been determined with a separately weighed amount of the sample. The detection limits of the microelements are 1×10−6 to 2×10−9%.

An investigation of a flameless atomic-absorption method for determination of aluminium, calcium, iron and magnesium in sewage sludge

The methods currently used for the determination of aluminium, calcium, iron and magnesium in sewage sludge are time-consuming. A rapid flameless atomic-absorption procedure, utilizing homogenization of diluted samples as the only pretreatment, has been compared with wet and dry analytical methods followed by flame atomic-absorption analysis, in a statistically designed experiment. Low-sensitivity (secondary absorption) lines have been used for the flameless analysis. The flameless atomic-absorption method described is better than all the other methods tested, with the exception of the nitric—perchloric—hydrofluoric acid digestion procedure. The time saved is substantial and the method could be used advantageously for routine analysis.

Use of Background Correction to Improve the Accuracy of the Selective Reduction Method for Determining Methyl Mercury in Fish

Background correction is used with a previously published flameless atomic absorption method for the concurrent determination of inorganic and methyl mercury. The use of background correction simplifies the procedure, but, more importantly, eliminates errors in mercury readings due to broad band absorption by other volatile compounds produced during the determination.

Flameless atomic-absorption determination of phosphorus using ZrC coated graphite atomizer tubes

A flameless atomic-absorption method for determination of phosphorus is developed, employing zirconium treated graphite tubes. The great improvement of the sensitivity with these tubes eliminates the necessity of adding La(NO3)3. The sensitivity does not vary from tube to tube and its maximal value is attained within the first 2–3 firings. The atomization signal is practically the same within the range of 2,600–2,800° C when the rise of the temperature is high (> 1,500° C/s). The best signal to noise ratio is obtained at 2,600° C. The detection limit is 0.05 ppm with injection of 50 μl. The method is applied to the analysis of a standard steel sample.

Problems in mercury determination in environmental samples

A marked decrease in parts per billion levels of mercury from distilled and natural waters during storage is discussed. Radioactive mercury ( 203 Hg) was added to distilled water, pond water, and seawater, and the loss of activity from the solutions was measured and compared to that of 65 Zn added to the same media. Behavior of inorganic and organic mercury is also examined using 203 HgCl 2 , and CH 3 203 HgCl. The specific behavior of Hg is mainly ascribed to three factors: vaporization, adsorption to the surface of containers and/or penetration through the walls, and susceptibility to biological activities in natural waters. Highly sensitive Hg analysis was therefore required for determining the low levels of Hg in natural waters. It was achieved by adopting the long quartz absorption cell to the cold-vapor flameless atomic absorption method. The sensitivity increases linearly with increasing cell length and the highest detection limit, 0.02 ng of Hg, was obtained when a 150-cm cell was used. Some precautions to eliminate a loss or change in the concentration of Hg in natural waters are stated.

Determination of Trace Metals in Cigarette Smoke by Flameless Atomic Absorption Spectrometry

Abstract A flameless atomic absorption method has been developed which permits the quick determination of the levels of trace metals in cigarette smoke. The total particulate matter (TPM) was collected by electrostatic precipitation and dissolved in methanol before analysis. In order to trap the last remaining traces of metals, the gas phase was passed through microporous filters which were analysed direct. The sensitivity of this method for the metals studied (Zn, Pb, Cd, Ni) is good in both the particulate and gas phase samples, with the sole exception of Ni in the gas phase. Results obtained by the flame and flameless methods are compared.

Epidemiological Experience with the Magos' Reagents in the Determination of Different Forms of Mercury in Biological Samples by Flameless Atomic Absorption

Total mercury was determined by the introduction of CdCl/sub 2/ in the presence of SnCl/sub 2/ to break the mercury to carbon bond with subsequent reduction of Hg/sup 2 +/ to Hg/sup 0/ which is determined by a flameless atomic absorption method. Inorganic mercury is determined in the absence of CdCl/sub 2/, and the organic mercury is calculated by the difference between total and inorganic mercury. The preparation of samples of whole blood, hair, urine, tissue, fish, and sediment samples is described in detail. Results obtained by this cold vapor atomic absorption method are shown to be in good agreement with results obtained for mercury content of samples analyzed by gas chromatography, proton microprobe, and x-ray fluorescence.

Determination of platinum in ores by a combined fire-assay and flameless atomic-absorption method

A combined fire-assay and flameless atomic-absorption procedure for the determination of platinum in ores is described. Silver beads obtained by cupellation are dissolved in aqua regia and made up to standard volume with 6 M hydrochloric acid, then 50-μl aliquots are injected into a carbon tube. From 0.5 to 5 ppm platinum can be determined with a precision of approximately 5%. The procedure tolerates other platinum metals and gold in the amounts present in the ores analysed.

Mercury content in several species of marine fish.

A survey was conducted to determine the total mercury content in fish available on the market or fished in the port of Genoa (Italy). Determinations were made with a variation of the flameless atomic absorption method. The tinned tuna showed high levels of mercury in Parathunnus obesus and Tunnus thynnus fished in the Mediterranean. Neothunnus macropterus and Katsuwonus pelamis had lower levels than in the same species of fresh fish. Mercury contents of tinned anchovies, sardines and mackerel were highest in Engraulis encrasicholus fished in the Adriatic sea and the lowest in the Clupea sardina compared to an average amount in Scomber scomber.

Investigations of reactions involved in flameless atomic absorption procedures : Part I. Application of high-temperature equilibrium calculations to a multicomponent system with special reference to the interference from chlorine in the flameless atomic absorption method for lead in steel

In order to study the interference from chlorine in the flameless a.a.s. method for lead in steel, high-temperature equilibrium calculations were applied to a system containing Fe, Pb, C, Cl, S, H, O, N and Ar. The temperatures as well as the input amounts of elements considered could be varied over a wide range, and a survey of the most important parameters governing the system was thereby obtained. The results indicate that a sample must be ashed in the presence of a sufficiently large amount of hydrogen and at a temperature of about 900 K in order to remove the chlorine from the graphite tube. Otherwise, the volatile lead chlorides PbCl 2, and PbCl are formed, which results in a decreased signal from lead.

Environmental Hygienic Studies on Mercury Compounds. I. Selective Determination of Methylmercury and Inorganic Mercury by Steam Distillation and Flameless Atomic Absorption Spectrophotometry

Selective determination of methylmercury and inorganic mercury in various samples by steam distillation and flameless atomic absorption method was established. This method is based on the following facts : (1) Alkylmercury chlorides are distilled by steam distillation in hydrogen chloride solution added with sodium chloride, while inorganic mercury remains in the distillation flask. (2) In sodium hydroxide solution containing a cupric ion, both methylmercury and inorganic mercury compounds (in this case, distillate contains only methylmercury compound) are reduced by tin (II), while in sulfuric acid solution, only inorganic mercury compound is reduced by tin (II). (3) The atomic mercury generated by mercury compounds absorbs the mercury resonance line at 253.7 nm. This method eliminated the most serious troubles in the determination of methylmercury such as the formation of a emulsion at benzene extractin, particulary in biological samples. The recovery rates of methylmercury and inorganic mercury contained in blood and placenta are 90-95% and 100-105%, respectively. This method was found to be applicable to various materials such as blood, animal organs, fish, and water and solid of river or lake bed.

Measuring picogram amounts of aluminum in biological tissue by flameless atomic absorption analysis of a chelate.

We describe a flameless atomic absorption method for aluminum determination in ethylenediaminetetraacetate extracts of biological tissues. Picogram quantities can be detected, and the technique appears to be more sensitive than other methods of aluminum determination used for biological samples. The extraction simplifies the method and virtually eliminates contamination with extraneous aluminum during the analysis. The extraction method might be useful for separating various other trace elements from biological tissues before analysis.

Determination of platinum, palladium, and lead in biological samples by atomic absorption spectrophotometry.

A flameless atomic absorption method for the coextraction of platinum and palladium from biological and environmental samples by high molecular weight amine (HMWA) is given. Also, methods for lead determination in biological samples by use of extraction flameless analysis and direct aspiration-flame analysis are reported. A study of lead contamination of Vacutainer tubes is given.

Determination of Platinum, Palladium, and Lead in Biological Samples by Atomic Absorption Spectrophotometry

A flameless atomic absorption method for the coextraction of platinum and palladium from biological and environmental samples by high molecular weight amine (HMWA) is given. Also, methods for lead determination in biological samples by use of extraction flameless analysis and direct aspiration-flame analysis are reported. A study of lead contamination of Vacutainer tubes is given.