The Determination of Traces of Nickel(II) By Solid State Spectroscopy

1975 ◽  
Vol 53 (3) ◽  
pp. 311-313 ◽  
Author(s):  
Douglas Earl Ryan ◽  
Jiri Holzbecher
Keyword(s):  
Detection Limit ◽  
Solid State ◽  
Light Absorption ◽  
Large Excess ◽  
Foreign Ions ◽  
Co Precipitation

Traces of nickel (II) are determined by measurement of light absorption in the solid state after co-precipitation with a large excess of α-benzildioxime. The detection limit is 0.2 µg Ni and nickel can be recovered even from 1000 ml sample volumes (i.e. < 1 ng/ml can be determined). Only a few foreign ions interfere.

The Determination of Traces of Bismuth by Solid State Luminescence

1974 ◽  
Vol 52 (10) ◽  
pp. 1942-1944 ◽  
Author(s):  
D. E. Ryan ◽  
H. Rollier ◽  
J. Holzbecher
Keyword(s):  
Detection Limit ◽  
Solid State ◽  
Calcium Oxalate ◽  
Co Precipitation ◽  
State Luminescence ◽  
Better Than

Traces of Bi(III) are determined with good selectivity by measurement of the luminescence (λex = 355 nm; λem = 430 nm) of CaO:Bi phosphor after co-precipitation with calcium oxalate and ignition at 850–900 °C. The detection limit is better than 0.01 μg Bi in 15 mg CaO; bismuth can be quantitatively recovered from 500 ml sample volumes and analysis is possible for 0.02 ng Bi/ml. The method has been successfully applied to the determination of trace amounts of bismuth added to synthetic blood and kidney samples.

scholarly journals All-solid-state polymeric screen printed and carbon paste ion selective electrodes for determination of oxymetazoline in pharmaceutical dosage forms

2019 ◽  
Vol 10 (4) ◽  
pp. 273-280
Author(s):  
Mohamed Salem Rizk ◽  
Emad Mohamed Hussien ◽  
Rasha Tharwat El-Eryan ◽  
Amira Mohamed Daoud
Keyword(s):  
Detection Limit ◽  
Solid State ◽  
Benzalkonium Chloride ◽  
Ion Exchanger ◽  
Drug Substance ◽  
Ion Selective Electrodes ◽  
Carbon Paste ◽  
Ph Range ◽  
Screen Printed

All-solid state potentiometric ion selective electrodes have the merits of being portable, small and suitable for small volume samples. Herein, disposable home-made screen printed polymeric ion selective electrode (SPE) is developed for determination of oxymetazoline (OXM) in pharmaceutical nasal drops and drug substance. Ion selective electrodes with optimal potentiometric response were achieved by careful selection of the ion exchanger and plasticizer. A screen printed electrode utilizing oxymetazoline-tetraphenyl borate (OXM-TPB) as an ion exchanger and dibutyl phthalate (DBP) as a plasticizer exhibited a Nernstian slope of 59.5±0.5 mV/decade (n=3) over the concentration range from 1×10-5 to 1×10-2 M OXM (r = 0.9999) with a detection limit of 5.0×10-6 M. The electrode is useful over a wide pH range from 4.0 to 8.0. The electrode showed a high selectivity for OXM against several common interfering ions. The potential interference from benzalkonium chloride was easily eliminated by treatment the sample with KI. Comparable potentiometric characteristics including linearity, detection limit, pH range and selectivity pattern were obtained with a carbon paste electrode (CPE) comprising same ion exchanger and plasticizer. The electrodes were successfully used for the assay of OXM in the drug substance and in the dosage form in presence of benzalkonium chloride with high accuracy (±2%) and precision (%RSD ˂2.5). The proposed method is simple, accurate and precise.

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

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.

Alcohol Determination by HPLC with Postcolumn Derivatization Based on the Thiosulfate-catalyzed Reaction of Alcohols and Cerium(IV) and Fluorescence Detection of Cerium(III)

2020 ◽  
Vol 16 ◽  
Author(s):  
Ikko Mikami ◽  
Eri Shibayama ◽  
Kengo Takagi
Keyword(s):  
Detection Limit ◽  
Fluorescence Detection ◽  
Reaction Rate ◽  
Detection Method ◽  
Fluorescence Detector ◽  
Reaction Solution ◽  
Optimum Detection ◽  
Postcolumn Derivatization ◽  
Sensitive Method

Background: Determination of a reducing substance based on the reaction between Ce(IV) and a reducing substance and fluorescence detection of Ce(III) generated has been reported as a selective and sensitive method. However, this method could not be applied to the determination of alcohol due to the low reaction rate of alcohol and Ce(IV). Objective: We found that thiosulfate catalytically enhanced reaction of alcohols (such as, methanol, ethanol, and propanol) and Ce(IV). Utilizing this effect, we developed a new method for the determination of alcohols. Results: In the presence of thiosulfate, an increase in fluorescence intensity was detected by injecting alcohol at concentrations of several millimolar, whereas it was not observed even at the concentration of 10% v/v (2 M for ethanol) in the absence of thiosulfate. The optimum detection conditions were determined to be 4.0 mM Ce(IV) sulfate and 0.50 mM thiosulfate, and the detection limit (S/N = 3) of ethanol under these conditions was 1 mM. In the calibration curves, changes in the slope were observed when the alcohol concentrations were approximately 10–25 mM. Using a thiosulfate solution containing ethanol as the reaction solution, a calibration curve without any change in slope was obtained, although the concentration of ethanol at the detection limit increased. The alcohols in the liquor and fuel were successfully analyzed using the proposed detection method as a postcolumn reaction. Conclusion: This new alcohol detection method using a versatile fluorescence detector can be applied to the postcolumn reaction of HPLC omitting need of time-consuming pretreatment processes.

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

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