نتایج جستجو برای: flame photometry
تعداد نتایج: 28795 فیلتر نتایج به سال:
The use of flame photometers has greatly simplified and expedited the estimation of sodium and potassium. Calcium is one of the elements which it is possible to determine by flame photometry, but little advantage has been taken of this fact in biological work for a number of reasons. The concentration of calcium in extracellular fluids is usually less than that of potassium ; a given quantity o...
Received for publication 12 July 1968. ashed in a muffle furnace at 600'C for at least three hours. Of the acid ammonium sulphate, 10 ml, and 30 ml of water are added to the ashed sample, and after warming to dissolve soluble material the contents are decanted with washing into a 50 ml centrifuge tube, the BaSO4 being washed into the tube as far as possible. The tube is centrifuged for 5 min, t...
Overall laboratory reproducibility for the Ames Seralyzer and plasma potassium test strips was less than 4% within the plasma reference range; and linearity extended from 2.1 to 10.2 mmol/l. Neither bilirubin nor lipaemia interfered in the analysis and selectivity for potassium over sodium was 450:1. Laboratory comparison with automated flame photometry and an indirect ion selective electrode s...
We present an improved Na+-selective liquid membrane electrode for measurement of Na+ concentrations in both undiluted serum and urine. The values for urinary Na+ obtained with the ion-selective electrode agree well with those obtained with the flame photometer. The correlation gives a standard residual deviation of +/- 2.7 mmol/L over the Na+ range of 25-280 mmol/L. In serum, this direct poten...
This is a kinetic assay for measuring K+ in serum, based on the activation of pyruvate kinase (EC 2.7.1.40) by K+. We eliminated interference from Na+ and NH4+ ions, which also activate this enzyme, by including Na+-binding and NH4+-consuming reagents in the reaction mixture. The assay was developed with and evaluated in the Cobas Fara centrifugal analyzer (and has been used in other kinetic an...
liVEETHODS of magnesium deternmination immbiologic fluids constitute an extensive literature. Magnesium ammonium phosphate precipitation (1), complexometric titration (2, 3), photometry (4, 5), fluorometry (6, 7), atomic absorption (8-11), and flame emission photometry (1214) have been employed for serum analysis. “Normal” ranges reported by these methods have been repeatedly tabulated (15-16) ...
We evaluated the performance of the lithium ion-selective electrode (ISE) in the Du Pont Na/K/Li analyzer. Lithium concentrations in 106 serum samples from patients being treated with lithium were measured in duplicate with the ISE and by flame photometry. The slope of the regression line for the two methods was 1.004 with a standard error of the estimate of 0.049 mmol/L (x = flame photometry, ...
The development of ion-selective electrodes (ISEs) for electrolyte measurements necessitates a re-evaluation of the biological and clinical interpretation of a result. In pathological situations (e.g., hyperlipidemia and hyperproteinemia) direct potentiometry is the method of choice for ion measurements in blood. However, the "plasma water effect" exists also in normal samples, requiring new re...
The variety of different anticoagulants used for blood samples has increased, but there is still need for a suitable anticoagulant for the routine estimation of sodium and potassium by flame photometry. So far the only satisfactory substance for this purpose has been the expensive calcium heparin (King and Wootton, 1956). Disodium sequestrene (Proescher, 1951 ; Hadley and Larson, 1953) and dipo...
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