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PubMedDate not supplied

Determination of lead in wine by graphite furnace atomic absorption spectrophotometry: interlaboratory study.

An interlaboratory study of a graphite furnace atomic absorption spectrophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to minimize matrix effects between standards and samples. Six wine test materials were prepared and sent to participants as 12 blind duplicate or split level samples. There was good agreement between results obtained from participants and target values (24-279 micrograms/L) obtained with an inductively coupled plasma-mass spectrometry method. The precision of the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard deviations ranged from 3 to 17%. Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for official purposes.

Food Analysis↗

PubMed1984

Determination of zinc in erythrocytes, granulocytes and serum by flame atomic absorption spectrophotometry.

Zinc was determined in granulocytes, erythrocytes and serum by flame atomic absorption spectrophotometry. Using a Teflon sampling cup, the sample volume for a single granulocyte zinc determination was reduced to 100 microliter. Zinc in serum and erythrocytes was measured by aspirating the sample at a rate of 5 ml/min. The total volume of blood used was 23-28 ml. The intra-assay coefficient of variation of the method for granulocytes was 0.01 and of the method for serum and erythrocytes 0.018. The corresponding inter-assay coefficient of variation was 0.037 and 0.03, respectively. Recovery of zinc determined by the method of aspirating the small volume (100 microliter) was 103% and by the method of aspirating 5 ml/min 97%. The coefficient of correlation between the two methods was r = 0.9968.

Adult↗

PubMed2001

Nutritional zinc balance in extremely low-birth-weight infants.

BACKGROUND: Zinc is important for metabolism, cell growth, immunity, and defense against oxygen radicals. Extremely low-birth-weight (< 1000 g) infants have higher nutritional needs, but information on zinc is scarce. The authors performed nutritional balances in 10 infants with birth weights of 500 to 999 g and who were fed with fortified human milk. METHODS: The authors collected infant feces, urine, and blood and human milk samples during 72 hours at 7 and 12 weeks of age. Zinc concentration was measured by inductively coupled plasma-mass spectrophotometry, atomic emission spectrophotometry, and instrumental neutron activation analysis. RESULTS: Mean (SD) intake via human milk was 379 (+/- 373) microg x kg(-1) x d(-1) during both balances. Urinary excretion was high at 7 weeks of age, decreased to half at 12 week, and was negatively correlated (P < 0.01) with weight gain. Mean absorption was slightly positive at 7 weeks of age but zero or negative in most infants at 12 weeks of age. Retention was negative in all infants at both observation periods, except in one infant during the second balance. Clinical zinc deficiency developed in one infant at 12 weeks of age. CONCLUSIONS: Zinc balances in extremely low-birth-weight infants are highly variable and usually negative. Controlled trials are needed to assess need for and benefits and risks of zinc supplementation.

Feces↗

PubMed1982

Alternative method for quantitative enzyme histochemistry of muscle fibers. Application of photographic densitometry combined with atomic absorption spectrophotometry.

The present study examines the use of photographic densitometry combined with atomic absorption spectrophotometry for the quantitation of enzyme activities (SDH and ATPase) in fresh frozen sections of rat tibialis anterior muscles. The technique eliminates some difficulties which are inherent in other methods. The reliability of the technique was found to be in the 98% range; the results were precise for all samples studied. The use of SDH to separate muscle fibers into "types" was found to be totally inaccurate since a full spectrum of activities was observed. ATPase activities could separate easily into two groups, but a continuum of ATPase activities was observed in the fast-twitch fibers. The simultaneous use of both enzymes was capable of separating the FG, FOG and SO fibers; however, variation within a single type was considerable and a great deal of information was lost when using any classification system. The continuum of SDH activities indicates the motor units are arranged as a spectrum of fatigue-resistant contractile units. The range of ATPase activities observed is comparable to ranges of motor unit contraction times emphasizing the importance of this enzyme in the regulation of contraction speed.

Adenosine Triphosphatases↗

PubMed1976

Digestion of fish samples for mercury determination by flameless atomic absorption spectrophotometry.

Methods of digestion of fish samples for mercury determination by flameless atomic absorption spectrophotometry have been investigated. Digestion in Teflon bombs, Kjeldahl flasks, or borosilicate test tubes gives comparable precisions and mercury recoveries. Because of their cost and effect in limiting productivity, Teflon bombs were considered unnecessary for analysis of fish samples. Experiments with cooked and uncooked fish samples have confirmed that no appreciable loss of mercury occurs during baking 30 min at 170 degrees C.

Fish Products↗

PubMedDate not supplied

Merging zones standard addition technique for determination of copper in beer by flow injection atomic absorption spectrophotometry.

A flow injection system for determination of copper in beer by atomic absorption spectrophotometry by the standard additions method is described. The manifold, based on the merging zone technique, prevents the burner head from clogging, as observed with the conventional reference method. With 5 standard additions, results are comparable with those of the reference method. Relative deviations were less than 5.8%, precision was better than 6.4%, and sampling rate was about 30 samples/ h. A less precise, less accurate, but faster procedure (75 samples/h) is possible with only 2 standard additions. The detection limit was 5 micrograms/L.

Beer↗

PubMed1996

Determination of zinc fractions in human blood and seminal plasma by ultrafiltration and atomic absorption spectrophotometry.

A simple and reliable method is described which combines ultrafiltration technique with atomic absorption spectrophotometry to determine the Zn fractions in human blood plasma and seminal plasma. Ultrafiltrable, loosely bound, and firmly bound Zn can be measured using this method in the presence or absence of ethylenediaminetetraacetic acid (EDTA). The YMT membranes for the ultrafiltration must be rinsed thoroughly before use. In contrast to Zn in blood plasma, a large part of Zn in the seminal plasma was found to be ultrafiltrable. This method can be applied to study the physiologically active part of Zn in body fluids related to various disease states.

Adult↗

PubMed1976

Determination of oxalic acid in urine by atomic absorption spectrophotometry.

A method is described for determination of oxalic acid in urine using atomic absorption spectrophotometry. The concentration of urinary oxalic acid is calculated by using the difference between two determinations of calcium: first, the excess of calcium in the supernatant after precipitation as calcium oxalate at pH 5, and second, the total calcium determined at pH less than 1 (endogenous and added). Analytical parameters (pH of precipitation, temperature, calcium and oxalate added, precipitation time, interfering substances) were studied with the aid of [14C]oxalic acid. A constant recovery of 95% of total oxalic acid allows the use of a correction factor. The accuracy and reproducibility of the method make it useful for routine determination of urinary oxalic acid.

Evaluation Studies as Topic↗

PubMed1975

Determination of beryllium, cadmium, and tellurium in animal tissues using electronically excited oxygen and atomic absorption spectrophotometry.

A method using electronically excited oxygen for destruction of organic matter and atomic absorption spectrophotometry for the determination of beryllium, cadmium and tellurium in animal tissues is presented. Samples are solubilized in dilute aqua regia after being subjected to an oxygen plasma, low-temperature (less than 190 degrees C) ashing system for 20 to 30 hours. Recovery data from spiked NBS freeze-dried bovine liver indicate a quantitative determination for the three elements. Limits of detection in micrograms of element per milliliter of solubilized sample solution are: beryllium, 0.05; cadmium 0.05; and tellurium, 0.50. Beryllium, cadmium, and tellurium assay data are reported for the fresh tissues of albino rats exposed to inorganic chemicals by oral or intraperitoneal routes. The tissues analyzed include: adrenal, brain, femur, heart, kidney, liver, lung, mesenteric lymph node, pancreas, prostate, seminal vesicle, spleen, testicle, and tracheal-bronchial lymph node.

Adrenal Glands↗

PubMed2001

[Simultaneous determination of trace cadmium and arsenic in grains using atomic absorption spectrophotometry].

Simultaneous determination of two components in single wavelength using interferencing effect and atomic absorption spectrophotometry assisted by simulated annealing-back propagation of error-artificial neural networks algorithm was realized, and simultaneous determination of trace cadmium and arsenic in grains was studied. The results obtained are satisfactory. The recoveries found by standard addition method are 91%-98% and 87%-92% respectively. Relative standard deviations for 7 times of determinations are all less than 4%. This method is fast and simple.

Arsenic↗

PubMed1989

Direct determination of lead in urine by flameless atomic absorption spectrophotometry with platform atomisation.

A direct method of urinary lead assay by flameless atomic absorption spectrophotometry is described for routine use in the clinical laboratory. It employs a simple sample pre-treatment procedure preceding automated analysis. Reproducibility, linearity and recovery were satisfactory without the need of standard addition. Mean and reference intervals of normal urine were similar to values reported in the literature.

Humans↗

PubMed1977

Determination of plasma and erythrocyte lithium concentrations by atomic absorption spectrophotometry.

We describe a method for determining plasma and erythrocyte lithium concentrations by atomic absorption spectrophotometry. Plasma and hemolyzed whole-blood are diluted and analyzed, with use of a lithium hollow-cathode lamp, at 670.8 nm. Erythrocyte lithium concentrations are calculated indirectly from the hematocrit. The standard deviation for a 0.43 mmol/liter pool of whole blood, run daily over 11 months, was +/-20 mumol/liter (CV=5.1). The lithium concentration of a lyophilized pool assayed periodically over the same period (n=127) was 1.84+/-0.05 mmol/liter (CV=2.7%). The relatively low erythrocyte/plasma lithium ratio and the microhematocrit centrifugation force (9600 to 13 600 X g) make corrections for trapped plasma insignificant. Problems with matrix matching and viscosity are overcome by using a plasma pool standard for calculations. Values for erythrocyte lithium concentrations were unchanged in samples stored at room temperature up to 24 h. Hemolysis appears to be of possible clinical significance. This method is useful as a routine clinical laboratory procedure for monitoring patients with affective disorders, who are undergoing therapy with lithium.

Erythrocytes↗

PubMed1990

[Study on the determination of zinc in plasma after oral administration of licorzin by atomic absorption spectrophotometry and the pharmacokinetics of zinc in healthy volunteers].

A rapid, accurate and sensitive atomic absorption spectrophotometry was established for the determination of zinc in plasma after oral administration of licorzin to healthy volunteers. The plasma sample diluted with de-ionized water (1:1) was determined directly. A 5% glycerol solution was used as the solvent of zinc standard solution. The recovery of the proposed method was 97.3 +/- 4.3%. The precisions (CV%) of within-day and day-to-day were less than 5%. The pharmacokinetics of zinc in healthy volunteers after oral administration of 2.5 g licorzin was studied. The results showed that an one-compartment model (Ka = K) was found in 10 healthy volunteers. The pharmacokinetic parameters were as follows: Ka = K = 0.380h-1, Tmax = 2.7h, V = 33.03 L, T1/2 = 1.9h.

Adult↗

PubMed1984

Comparison of diluents for serum magnesium estimation by atomic absorption spectrophotometry.

In order to determine the optimal diluent for the determination of Mg by atomic absorption spectrophotometry, the following diluents were tested: deionized water, 0.1 mol/l HCl, 2.5 g/l SrCl2, 1.8 g/l LaCl3, 17.7 g/l LaCl3, half-saturated 8-hydroxyquinoline (oxine), 40 g/l trichloroacetic acid (TCA)/17.7 g/l LaCl3, and 100 g/l TCA/0.1 mol/l HCl. The calibration curves, obtained on the same day, were passed through the origin in the form of linear regressions. The variances about the calibration curves did not differ significantly (p greater than 0.05), while the calibration slopes for the diluents differed significantly (p less than 0.001). A standard serum solution was analyzed with the use of the eight diluents and the mean results did not differ significantly (p greater than 0.05). The % coefficient of variation varied from 0.8 to 2.0 and the percent recovery ranged from 95.5 to 102.5. The 99% confidence interval (CI) ranged from 0.02 to 0.09. Since conventional CIs do not take into account the random error of the calibration curve, the inverse CI were also calculated for each diluent. On both the conventional estimates and on the inverse CI, strontium chloride gave the best results, but only marginally in view of the interassay variability of approximately 1%.

Calibration↗

PubMed1998

Direct determination of selenium in human blood plasma and seminal plasma by graphite furnace atomic absorption spectrophotometry and clinical application.

Direct determination of selenium (Se) in body fluids by graphite furnace atomic absorption spectrophotometry (GFAAS) may suffer from problems like severe background, matrix effects, preatomization losses, and spectral interferences. In this study we evaluate critically the influence on the accuracy of the direct determination of Se in blood plasma and seminal plasma by GFAAS, and propose a simple, rapid, and accurate method, suitable for routine clinical analysis. The method for blood plasma is mainly based on studies by the use of matched matrix and a Pd-Ni modifier, but for seminal plasma only a Pd modifier is required. The method developed was also applied to study the Se distribution in plasma protein fractions of patients with hepatocellular carcinoma. The Se in plasma of patients was significantly lower than that of the controls. The distribution pattern of Se in blood plasma fractions of patients was also different from that of the controls.

Adult↗

PubMed1977

Analysis of foods for arsenic and selenium by acid digestion, hydride evolution atomic absorption spectrophotometry.

A method based on acid digestion, hydride evolution atomic absorption spectrophotometry for estimating microgram and submicrogram quantities of As and Se in foods was developed and evaluated. Samples up to 3 g dry weight were digested with HNO3-HCIO4-H2SO4. As and Se in aliquots of the digests were reduced with NaBH4 to volatile hydrides, using laboratory-constructed and commercially available generators. As and Se were estimated by transient signal atomic absorbance measurements as the hydrides were decomposed in an Ar-H2-entrained air flame. Recoveries of inorganic As and Se added at levels of 0.1-1.0 microgram/g to a variety of foods ranged from 70 to 125%. Analyses of several standard reference samples indicated the method is capable of recovering native analytes. Detection limits for the determinative step and the method as a whole were as low as 5 and 25 ng, respectively, for both elements.

Arsenic↗

PubMed1986

Copper in seminal plasma: comparison of two processing methods for atomic absorption spectrophotometry.

Fifty-three randomly selected seminal plasma samples were assayed for copper by atomic absorption spectrophotometry. All the samples had undergone two accepted processing methods--wet oxidation and dilution. The results were compared, and a highly significant difference was seen (p less than 0.001). The dilution method gave the better reading and was simpler in processing. The author recommends the dilution method for elemental study in seminal plasma by using atomic absorption spectrophotometry.

Copper↗

PubMed1989

Determination of Na and K in the rat lens by atomic absorption spectrophotometry.

A new procedure is described for determination of sodium and potassium in rat lenses with atomic absorption spectrophotometry. Samples were prepared by soaking of the ground or the intact lens in deionized water. For potassium determinations HNO3 dissolution was also tried. Deionized water or CsCl aqueous solution was adopted for dilution for measurement. At absorbances up to 1.0 absorbance unit only measurements on HNO3 dissolved lenses diluted in deionized water were compatible with a linear absorbance function. At absorbances below 0.2-0.3 absorbance units all combinations were in agreement with a linear absorbance function. Grinding of the lens was found to increase the variability but did not change the level. HNO3 dissolution did not increase the level. Dilution with CsCl increased the sensitivity and decreased the variability. A schedule is proposed for determination of sodium and potassium in which lens samples are obtained by soaking in deionized water. Aqueous solution of CsCl is suggested for dilution.

Animals↗