Colorimetric determination of nitrogen oxides in gas mixture and of nitrite ions in solution of benzidine and m-phenylenediamine

A hot-wire flowmeter was evaluated for clinical applicability. 1) Calibration with a syringe could be done if emptying duration was 1-15 s. 2) Outputs linearly decreased with decreasing concentration of N2 in O2. Outputs with CO2 in O2 and N2O in O2 represented nonlinear convex relationships with varying concentrations of CO2 and N2O. Correction for each gas mixture to be measured is required. 3) Outputs linearly decreased with decreasing barometric pressure. 4) Stability assessed with a piston respirator was excellent (within +/- 2% of syringe volume) after 15 min warmup time. However, daily calibrations are recommended in clinical situations. 5) Nebulization, if not excessive, was acceptable if the expired gas was measured at the mouth. 6) Hot-wire burning, which occurred when it was partially in contact with materials whose specific heat differed with air, was successfully protected with a simple shutoff circuit. 7) The possibility of producing nitrogen oxides by the catalytic action of the platinum hot-wire was denied by colorimetric determination. Interchangeability and sterilizability of transducers and improved mechanical strength with platinum-rhodium alloy are also discussed.

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A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

Gastroenterology ◽

10.1016/s0016-5085(59)80003-2 ◽

1959 ◽

Vol 36 (2) ◽

pp. 193-201 ◽

Cited By ~ 46

Author(s):

Julius A. Goldbarg ◽

Esteban P. Pineda ◽

Benjamin M. Banks ◽

Alexander M. Rutenburg

Keyword(s):

Enzymatic Activity ◽

Colorimetric Determination ◽

Health And Disease ◽

Urine Serum

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Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i7.6703 ◽

2013 ◽

Vol 12 (7) ◽

pp. 460-465

Author(s):

Sameer Amereih ◽

Zaher Barghouthi ◽

Lamees Majjiad

Keyword(s):

Drinking Water ◽

Detection Limit ◽

Complex Formation ◽

Molar Absorptivity ◽

Colorimetric Determination ◽

Zirconium Complex ◽

Reliable Determination ◽

Percentage Recovery ◽

Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

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Colorimetric Determination of Amoxicillin in Pure and some Pharmaceutical Formulations Via Reaction with Potassium Permanganate as Oxidant Reagent

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.2.2 ◽

2019 ◽

Vol 10 (02) ◽

Author(s):

Abbas Shebeeb Al-kadumi ◽

Sahar Rihan Fadhel ◽

Mohammed Abdullah Ahmed ◽

Luma Amer Musa

Keyword(s):

Potassium Permanganate ◽

Pharmaceutical Preparations ◽

Pharmaceutical Formulations ◽

Atomic Emission ◽

Basic Medium ◽

Photometric Method ◽

Colorimetric Determination ◽

Spectrophotometric Methods ◽

Label Claim

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.

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