Optimized atomic absorption spectrophotometry of calcium in erythrocytes.

1987 ◽  
Vol 33 (11) ◽  
pp. 2004-2007 ◽  
Author(s):  
S Nomoto ◽  
S Shoji

Abstract We sought to establish optimum conditions for measuring calcium in erythrocytes by atomic absorption spectrophotometry. The conditions we selected are as follows. Wash one volume of fresh heparin-treated packed cells once with 30 volumes of isotonic buffered saline (pH 7.4) at a temperature somewhat exceeding 25 degrees C. Dilute the washed packed cells 10-fold with 12 mmol/L hydrochloric acid, and analyze the supernate for calcium. Measure the hematocrit of the washed packed cells, then analyze an aliquot of them for calcium, using a computer-readout type of flame or a non-flame atomic absorption spectrophotometer equipped with a pyrocoated graphite tube. The temperature program is 1000 degrees C for ashing [corrected] and 1800 degrees C for the atomizing cycle. Intraday and day-to-day reproducibility of the assay was 6.55% and 8.19%, respectively, at the mean concentration of calcium in the erythrocytes of healthy adults, which is 4.30 mumol/L.

1975 ◽  
Vol 21 (4) ◽  
pp. 537-543 ◽  
Author(s):  
Merle A Evenson ◽  
C Thomas Anderson

Abstract We describe a method of analysis for copper, cadmium, and zinc in a 15-mg (wet weight) sample of human liver by atomic absorption spectrophotometry. The sample is digested with nitric acid (1.0 mol/liter), evaporated, and dilute HNO3 (10 mmol/liter) added. The reconstituted acid mixture is injected into the graphite tube atomizer for analysis of Cu and Cd and aspirated into the airacetylene flame for measurement of Zn. The absorbance for each metal is suppressed with increasing pH. NaNO3, KNO3, KCl, and NaCl (e.g.) quench the Cd absorbance in acid solutions that contain no protein, but not in the presence of protein. Metal ions added to the predigestion human liver sample at 10% and 100% of the intrinsic metal concentrations were, respectively, 93% and 90% accounted for analytically in the case of Cu, 98% and 102% for Zn, and 101% and 93% for Cd. Analysis of a National Bureau of Standards' Bovine Liver Standard Reference Material yielded results corresponding to 99% (Cu), 112% (Zn), and 91% (Cd) of the mean expected concentrations of these metals. The between-run coefficient of variation for the bovine liver material was 6% for Cu, 9% for Zn, and 10% for Cd. For 16 histologically normal samples of human liver, the mean values were: Cu, 26; Zn, 293; and Cd, 6.0 nanograms of metal per milligram dry weight, in agreement with values published previously. The method can be easily and reliably applied to small samples of liver obtained by closed-needle biopsy.


1975 ◽  
Vol 21 (4) ◽  
pp. 588-590 ◽  
Author(s):  
Berlslav Momčilović ◽  
Bartholomeus Belonje ◽  
Bhagwan G Shah

Abstract Zinc in pooled human serum, diluted 10-fold with demineralized water, was determined by flame atomic absorption spectrophotometry. Recoveries of zinc added to the serum were calculated by use of standards prepared in water, physiological saline, synthetic serum, or dilute HNO3 (10 ml/liter). The flow rates were essentially the same (9.1 to 9.3 ml/min) for water, diluted synthetic serum or actual human serum, and diluted nitric acid. The mean apparent percentage recoveries (±SD) were the best (102.6 ± 2.5) when the standards were prepared in nitric acid; the values obtained when standards in water were used were too high (111.5 ± 3.9); those with standards prepared in physiological saline (92.0 ± 3.2) or synthetic serum (92.3 ± 2.5) were too low.


1983 ◽  
Vol 29 (3) ◽  
pp. 486-491 ◽  
Author(s):  
R Palm ◽  
R Sjöström ◽  
G Hallmans

Abstract This method for direct determination of Zn in cerebrospinal fluid (CSF) involves flame atomic absorption spectrophotometry with a pulse nebulizer technique. Standard solutions of Zn in 150 mmol/L NaCl were used. We could account for 88% of added standard with the method in individual samples from 10 patients and in pooled CSF. The method is acceptably precise, CVs in pooled CSF ranging from 4 to 12%. The mean CSF-Zn concentration for nine healthy men was 0.18 (SD 0.04) mumol/L and for nine healthy women 0.15 (SD 0.03) mumol/L, a statistically insignificant difference. These values are lower than those in previous reports, which may have been the result of contamination problems, nonatomic absorption, or nonstandardized sampling. In the healthy volunteers, the CSF-Zn concentration was positively correlated with serum-Zn, CSF-protein, and CSF-albumin concentrations, as well as with the CSF/serum ratio for albumin.


2019 ◽  
Vol 79 (5) ◽  
pp. 833-841 ◽  
Author(s):  
Kanokporn Supong ◽  
Parnuwat Usapein

Abstract Forms of copper that are highly soluble in aquatic environments are used as chemical reagents in a variety of industries, especially copper complexes. Wastewater containing copper complexes can be difficult to treat and analyse. Normally, flame atomic absorption spectrophotometry (FAAS) is a favourable technique for analysing metal ions in wastewater, but is less reliable for copper analysis owing to the influence of copper oxides. To solve this problem, it is necessary to adjust the atomization and delay times. The objective of this study was to use FAAS to accurately determine the quantity of complexed copper in synthetic wastewater, using increased atomization and delay times. The method showed excellent linearity in the copper standard concentration range of 1–5 mg L−1. The sensitivity of the analysis was 0.023 mg L−1. The percentage of recovery and the relative standard deviation were 85.02% and 0.75%, respectively. The experimental results demonstrated that the estimation of uncertainty from preparation of working standard, repeatability uncertainty, instrument deviation, calibration curve and recovery uncertainty were 8.2 × 10−4, 4.49 × 10−4, 7.21 × 10−4, 21.25 × 10−4, and 98.19 × 10−4, respectively. Overall, the results showed the suitability of the FAAS method for determining copper in synthetic wastewater.


1984 ◽  
Vol 67 (1) ◽  
pp. 186-187
Author(s):  
Teresa M Serra ◽  
J F Vale Serrano

Abstract Lead was determined in the presence of whole multiples of the P/Ca ratio found in Portuguese canned fish by flame atomic absorption spectrophotometry with and without using an ashing aid. Under our experimental conditions, use of the ashing aid eliminates P and Ca interference. Results with real samples, spiked with 1, 2,3, and 4 ppm lead, are presented and statistically treated.


1978 ◽  
Vol 24 (9) ◽  
pp. 1485-1490 ◽  
Author(s):  
J E Gorsky ◽  
A A Dietz

Abstract Aluminum, generally considered non-essential and non-toxic, may accumulate in toxic amounts in the brain in cases of chronic renal failure. We describe a procedure for its analysis in biological fluids by atomic absorption spectrophotometry with a graphite furnace. No sample preparation is required and the procedure is sensitive at the appropriate concentrations. A sample of serum or urine is pipetted into the interior of the graphite tube, where it is sequentially dried, charred, and atomized. Precautions for sample handling are discussed and instrument settings are defined. Precision and accuracy of the method are evaluated, as are the effects of salts, protein content of serum, and specific gravity of urine. Serum of 23 persons who were not consuming aluminum-containing antacids contained 28 +/- 9 (SD) microgram of Al per liter (1.02 +/- 0.33 mumol/liter).


1983 ◽  
Vol 66 (1) ◽  
pp. 130-134
Author(s):  
Robert R Brooks ◽  
Janine A Willis ◽  
John R Liddle

Abstract Instrumental parameters and other variables were studied to establish the optimum indicators for determination of selenium by atomic absorption spectrophotometry using the hydride generation procedure with cold-trapping. Optimum conditions were established by consideration of the following variables: volume of reaction solution, acid concentration in the reaction mixture, lapse of time after last addition of borohydride, method of addition of borohydride, carrier gas flow rates, position of source beam in the flame cell, oxidation state of selenium, and effect of drying the cold trap between successive determinations. This latter procedure greatly improved the reproducibility of the technique (from ±28% to ±2%. The limit of detection was about 2 ng selenium.


1991 ◽  
Vol 74 (5) ◽  
pp. 812-814 ◽  
Author(s):  
Philip J Oles ◽  
Wanda M Graham

Abstract Food matrixes were digested by treatment with nitric acidsulfuric acid-hydrogen peroxide mixtures and heating with a commercially available microwave apparatus. The digests were analyzed for sodium, potassium, magnesium, iron, calcium, zinc, copper, and manganese content by flame atomic absorption spectrophotometry. A total of 3 digestion programs were adopted for a variety of food matrixes. Microwave digestion times of 30-45 mln were normally sufficient for obtaining clear digests compared to hot plate digestion times of 8-12 h. Precision for microwave digestion of most nutrients was equal to or better than that of hot plate digestion. Microwave digestion gave comparable results for the nutrient elements. National Institute of Standards and Technology reference materials were analyzed for nutrient content after microwave digestion and the results compared favorably with the certified values. A laboratory breakfast cereal control sample with a history of over 20 separate hot plate digestions was prepared using the microwave technique. Results for the 8 elements were within ±7% of the hot plate digestion values. Predlgestlon spikes were recovered from several food matrixes with no effects resulting from Incomplete digestion of samples.


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