Continuous-flow determination of serum inorganic phosphate with a single reagent--the vanadomolybdate method re-evaluated.

1977 ◽  
Vol 23 (7) ◽  
pp. 1275-1280 ◽  
Author(s):  
H Baadenhuijsen ◽  
H E Seuren-Jacobs ◽  
A P Jansen
Keyword(s):  
Acid Medium ◽  
Inorganic Phosphate ◽  
Room Temperature ◽  
Visible Range ◽  
Color Development ◽  
Optimum Reaction ◽  
The Stability ◽  
Serum Inorganic Phosphate ◽  
Tungsten Lamp

Abstract The merits of the vanadomolybdate method in the determination of inorganic phosphate are highly underestimated with regard to the simplicity of the method and the stability of both the reagents and the color that is formed. The absorption curve of the phosphovanadomolybdate complex, with its maximum at 335 nm, extends into the visible range of the spectrum. This permits measurements with inexpensive tungsten-lamp colorimeters. On-stream dialysis is best done in a nitric acid medium, 0.15 mol/liter. Paralleled by the change in the H2PO4-/H3PO4 ratio, appreciable protein binding and poor dialysis efficiency are seen at lower acid concentrations (pH greater than 1.0). Optimum reaction-mixture concentrations of vanadium and molybdenum appeared to be respectively 0.2 and 5 mmol/liter up to 3 mmol of phosphate per liter, in a final acid medium of 0.2 mol/liter, concentrations considerably lower than those used in some studies published earlier. Color development with the stable combined reagent is complete after only 20 s at room temperature and the color is stable for at least 2 h. Figures on precision and accuracy demonstrate the reliability of the method.

Error introduced by specimen handling before determination of inorganic phosphate concentrations in plasma and serum.

1976 ◽  
Vol 22 (11) ◽  
pp. 1909-1911 ◽  
Author(s):  
J E Carothers ◽  
N M Kurtz ◽  
J Lemann
Keyword(s):  
Coefficient Of Variation ◽  
Inorganic Phosphate ◽  
Room Temperature ◽  
Processing Technique ◽  
Healthy Adults ◽  
Blood Sampling ◽  
Specimen Handling ◽  
Evacuated Tubes ◽  
Serum Inorganic Phosphate

Abstract Values for serum inorganic phosphate (Pi) concentrations in groups of healthy adults vary widely, the coefficient of variation ranging from 10 to 15%. We undertook to determine in 23 healthy adults whether part of this variation could be accounted for by (a) drawing blood in syringes vs. evacuated tubes (b) the time between blood sampling and separation of serum or plasma, and (c) the prevention of clotting. Values were unaffected by a, decreased significantly with time at room temperature between blood sampling and separation of cells in both serum and plasma, and were significantly lower in plasma than in serum. The group coefficient of variation for Pi averaged 13% and was uninfluenced by the blood-processing technique.

scholarly journals Indirect spectrophotometric determination of gentamicin and vancomycin antibiotics based on their oxidation by potassium permanganate

2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany
Keyword(s):  
Acid Medium ◽  
Potassium Permanganate ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Subsequent Determination ◽  
Optimum Reaction ◽  
Acid Orange Ii ◽  
Sulphuric Acid Medium

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.

Simple Manual Procedure for Determination of Serum Triglycerides

1975 ◽  
Vol 21 (6) ◽  
pp. 768-770 ◽  
Author(s):  
Jose Mendez ◽  
Barry Franklin ◽  
Harry Gahagan
Keyword(s):  
Quality Control ◽  
Calibration Curve ◽  
Room Temperature ◽  
Extraction Procedure ◽  
Serum Triglycerides ◽  
Modified Method ◽  
Color Development ◽  
Significant Difference ◽  
Control Samples

Abstract We describe a modified method for determining serum triglycerides (triacylglycerols), which is based on the heptane extraction procedure of Gottfried and Rosenberg [Clin. Chem. 19, 1077 (1973)] with the stable saponification, oxidation, and color development reagents of Neri and Frings [Clin. Chem. 19, 1201 (1973)]. This modified method eliminates one heating step, reduces saponification time to 5 min, absorbances are read at room temperature, and the calibration curve is linear to 3.0 g/liter. A sample comparison between the proposed method and the automated Block and Jarrett [Am. J. Med. Technol. 35, 1 (1969)] procedure showed no significant difference (r = 0.98). The coefficient of variation (47 duplicate samples) for the modified method was 6.3%. Further validation was obtained from analysis of quality-control samples; the proposed method gave equivalent values.

scholarly journals Стабильность функциональных характеристик прозрачных электродов на основе трехслойной структуры ZnO : Ga/Ag/ZnO : Ga

2022 ◽  
Vol 48 (2) ◽  
pp. 51
Author(s):  
А.Ш. Асваров ◽  
А.К. Ахмедов ◽  
А.Э. Муслимов ◽  
В.М. Каневский
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Room Temperature ◽  
Layer Structure ◽  
Visible Range ◽  
Practical Application ◽  
Transparent Conducting ◽  
Average Transmittance ◽  
The Stability

Since to the stability of the functional properties of a transparent conducting three-layer structure ZnO:Ga/Ag/ZnO:Ga is important for practical application, we studied its long-term durability and thermal stability in air environment. It has been demonstrated that after prolonged interaction with the air environment at room temperature (~ 1000 h) and further heat treatment in air at temperatures up to 450 ° C (up to 10 h), the three-layer structure retains its integrity and is characterized by a low sheet resistance Rs = 2.8 Ω/sq at average transmittance in the visible range Tav of 82.1%.

Automated determination of urinary Na+, K+, chloride, inorganic phosphate, urea, and creatinine without sample dilution, with the "RA-XT".

1989 ◽  
Vol 35 (3) ◽  
pp. 481-483
Author(s):  
P D Fesus ◽  
M Pressac ◽  
F Braconnier ◽  
P Aymard
Keyword(s):  
Continuous Flow ◽  
Inorganic Phosphate ◽  
Room Temperature ◽  
Flow Analysis ◽  
Continuous Flow Analysis ◽  
Sample Dilution ◽  
Automated Determination

Abstract We describe how concentrations of chloride, urea, inorganic phosphate, and creatinine in urine can be measured directly, without manual sample dilution, in a discrete analyzer (the Technicon "RA-XT"). These methods were accurate for concentrations of chloride up to 280 mmol/L, urea up to 500 mmol/L, inorganic phosphate up to 50 mmol/L, and creatinine up to 30 mmol/L. CVs are less than 3% nd results correlate well with those obtained by continuous-flow analysis (SMA-II). All these reagents are stable at room temperature for three weeks. Analyses are easy to perform and infrequent calibration is required.

A New Simple Semimicro Method for Colorimetric Determination of Urea

1963 ◽  
Vol 9 (1) ◽  
pp. 102-108 ◽  
Author(s):  
J J Coulombe ◽  
L Favreau
Keyword(s):  
Acid Medium ◽  
Rapid Method ◽  
Room Temperature ◽  
Colorimetric Determination ◽  
Red Color ◽  
Color Complex ◽  
Blood Filtrate ◽  
Diacetyl Monoxime

Abstract A new simple and rapid method for quantitative semimicro determination of blood urea is presented. Diacetyl monoxime and thiosemicarbazide form in acid medium with urea a red color complex with a maximum adsorption at 530 mµ stable at room temperature and requiring 0.2 ml. of 1:10 blood filtrate.

scholarly journals The effect of selected substances on the stability of standard solutions in voltammetric analysis of ascorbic acid in fruit juices

2019 ◽  
Vol 17 (1) ◽  
pp. 655-662
Author(s):  
Radosław Kowalski ◽  
Artur Mazurek ◽  
Urszula Pankiewicz ◽  
Marzena Włodarczyk-Stasiak ◽  
Monika Sujka ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Room Temperature ◽  
Nutritive Value ◽  
Fruit Juices ◽  
Optimum Concentration ◽  
Voltammetric Analysis ◽  
The Stability ◽  
Standard Solutions

AbstractThe objective of the study was to identify suitable additives stabilizing standard solutions of ascorbic acid (AA) that would not cause interference in the analytical process with the use of voltammetry in the determination of the AA content in food products. In addition, the effect of various conditions of storage of selected fruit juices and drinks on the concentration of vitamin C was studied. The study demonstrated that AA degradation was inhibited the most effectively by tartaric acid and its optimum concentration was set to 200 mg L-1. Analysis of selected fruit juices stored in various temperature conditions confirmed that an elevation of temperature and extension of the time of storage caused a decrease in the content of vitamin C in the analyzed samples, while closing the packages caused a limitation of the changes in concentration of this vitamin. On the basis of literature data and of the results obtained in the present study it can be concluded that fruit juices should be stored at a temperature lower than room temperature to retain their nutritive value.

THE MICROCOLORIMETRIC DETERMINATION OF INORGANIC PHOSPHATE IN PLASMA AND URINE: I. QUANTITATIVE INVESTIGATION OF PRESENT COMMON PROCEDURES II. A SENSITIVE AND STABLE METHOD FOR PLASMA, SERUM, AND URINE

1949 ◽  
Vol 27e (5) ◽  
pp. 265-274 ◽  
Author(s):  
John R. Polley
Keyword(s):  
Inorganic Phosphate ◽  
Color Stability ◽  
Stable Method ◽  
Quantitative Investigation ◽  
Sodium Potassium ◽  
Factors Affecting ◽  
Color Development ◽  
The Common ◽  
Serum And Urine

A quantitative investigation of the common colorimetric procedures used for determining inorganic, phosphate was made to determine the factors affecting the sensitivity and color stability. A method is presented that is accurate to within ± 2% and is sufficiently sensitive to give quantitative color development with less than 1 γ of phosphorus. The color produced is quite stable for colorimetry. The method has been adapted to the determination of phosphorus in 0.1 or 0.02 ml. of plasma, serum, or urine or in the protein-free filtrate residue from the determination of sodium, potassium, calcium, and chloride in 0.4 ml. of plasma.

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