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.

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.

Dosage du Sr-90 dans l'eau des lacs et des rivières du Québec par précipitation avec l'oxine et comptage β

1988 ◽  
Vol 66 (1) ◽  
pp. 174-177 ◽  
Author(s):  
E. Haddad ◽  
L. Zikovsky
Keyword(s):  
Detection Limit ◽  
Surface Waters ◽  
New Method ◽  
The Mean ◽  
Better Than

A new method for the determination of Sr-90 dissolved in surface waters has been developed. It is based on the precipitation of Sr with 8-hydroxyquinoline at pH 11.3 and counting of β particles with energy above 150 keV. The detection limit obtained is 0.5 mBq/L and the mean yield is 28%. The decontamination factors from other β emitters achieved are better than 10 000. This method has been used to measure the Sr-90 in 5 lakes and 5 rivers in Québec and activities ranging from 3 to 15 mBq/L were obtained. This new method is as efficient and reliable as conventional techniques while being less tedious.

Solid-state luminescence determination of traces of beryllium with dinaphthoyl-methane

1975 ◽  
Vol 76 (2) ◽  
pp. 467-469 ◽  
Author(s):  
D.E. Ryan ◽  
M. Granda ◽  
M. Janmohammed
Keyword(s):  
Solid State ◽  
State Luminescence

Determination of Inorganic Selenium Species in Marine Waters by Hydride Generation - AFS

2004 ◽  
Vol 57 (10) ◽  
pp. 937 ◽  
Author(s):  
Bronwyn D. Wake ◽  
Edward C. V. Butler ◽  
Alison M. Featherstone ◽  
Patti Virtue ◽  
Bernard Averty ◽  
...  
Keyword(s):  
Detection Limit ◽  
Fluorescence Detection ◽  
Hydride Generation ◽  
Reduction Step ◽  
Marine Waters ◽  
Atomic Fluorescence ◽  
Inorganic Selenium ◽  
Cryogenic Trapping ◽  
Better Than

A method based on hydride generation with cryogenic trapping and atomic fluorescence detection was developed that is capable of determining both inorganic Se species (SeIV and SeVI) while at sea. Evaluation of the system for optimal performance was made for each stage of the analysis and detection sequence, as well as for the SeVI reduction step. A detection limit of 0.4 ng L−1 Se in a 10 mL sample was achieved using this method. Precision was better than 3.5% for 25, 100, and 1000 ng L−1 SeIV standard solutions. Accuracy was determined by recovery studies using natural samples and a certified reference seawater (NASS-5).

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.

The determination of traces of lead(II) by solid-state luminescence

1974 ◽  
Vol 73 (1) ◽  
pp. 49-52 ◽  
Author(s):  
D.E. Ryan ◽  
J. Holzbecher ◽  
H. Rollier
Keyword(s):  
Solid State ◽  
State Luminescence

The Determination of Trace Elements by Solid State Luminescence

1973 ◽  
Vol 6 (8) ◽  
pp. 721-729 ◽  
Author(s):  
D. E. Ryan ◽  
R. J. Prime ◽  
J. Holzbecher ◽  
R. E. Young
Keyword(s):  
Trace Elements ◽  
Solid State ◽  
State Luminescence

Determination of Bronopol, Bronidox, and Methyldibromo Glutaronitrile in Cosmetics by Liquid Chromatography with Electrochemical Detection

1994 ◽  
Vol 77 (5) ◽  
pp. 1132-1136 ◽  
Author(s):  
J W Weyland ◽  
A Stern ◽  
J Rooselaar
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Detection Limit ◽  
Electrochemical Detection ◽  
Cosmetic Products ◽  
Extraction Solvent ◽  
Relative Standard ◽  
Sample Amount ◽  
Better Than

Abstract A method for the simultaneous determination of methyldibromo glutaronitrile, bronopol, and broni-dox in cosmetics, based on liquid chromatography with electrochemical detection, is described. The method is suitable for both aqueous products and emulsions. The detection limit is better than 0.002% for all analytes. Recoveries from an emulsion, spiked to concentrations of 0.03% of the analytes, were 100.4% for bronopol [relative standard deviation (RSD), 0.43%], 97.1% for bronidox (RSD, 0.83%), and 98.4% for methyldibromo glutaronitrile (RSD, 1.7%). Repeatabilities were calculated from 10 replicate analyses of commercial samples. The repeatability for bronopol from an emulsion containing 0.047% bronopol was 0.0027% (RSD, 1.99%); for bronidox from a lotion containing 0.027% bronidox, 0.0014% (RSD, 1.86%); and for methyldibromo glutaronitrile from an emulsion containing 0.031% methyldibromo glutaronitrile, 0.0019% (RSD, 2.16%). A ruggedness test showed that sample amount influenced the results for all 3 analytes. The results obtained for bronidox also depended on detection parameters and composition of extraction solvent. The method was applied to 138 cosmetic products and performed trouble free during these analyses. Bronopol was found in 14 samples, and bronidox was found in 4 samples, including a baby hair lotion, in which it is prohibited. Methyldibromo glutaronitrile was present in 27 samples, including creams, lotions, and sun protection cosmetics.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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