Automated Colorimetric Determination of Phenylephrine Hydrochloride in Drug Formulations. II. Collaborative Study

1971 ◽  
Vol 54 (3) ◽  
pp. 600-602
Author(s):  
Michel Margosis
Keyword(s):  
Coefficient Of Variation ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Colorimetric Determination ◽  
Good Recovery ◽  
Drug Formulations ◽  
Phenylephrine Hydrochloride ◽  
Automated Method

Abstract The automated colorimetric method designed by Lane for the analysis of phenylephrine HCl in drug formulations has been submitted to a collaborative study. Five samples, including 2 with known interferences, were sent to 9 collaborators. The results were subjected to statistical evaluation. These show good recovery and a maximum interlaboratory coefficient of variation of 4.5%. The automated method as evaluated in this study has been adopted as official first action.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

Collaborative Study of the Ion-Pair Column Partition Method for the Determination of Phenylephrine.HC1 in Drug Formulations

1970 ◽  
Vol 53 (1) ◽  
pp. 120-122
Author(s):  
Michel Margosis
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Ion Pair ◽  
Confidence Limits ◽  
Drug Formulations ◽  
Three Solutions ◽  
The Mean ◽  
Partition Method ◽  
Collaborative Evaluation

Abstract Three solutions containing varying amounts of phenylephrine.HC1 were subjected to a collaborative evaluation of the ion-pair column partition method of Levine and Doyle. Results submitted by 20 collaborators were evaluated statistically. Recoveries averaged 99.0, 100.8, and 103.5% with 95% confidence limits of the mean of ±0.71, ±0.53, and ±0.85%, respectively. The method is recommended for adoption as official first action. The colorimetric method approved last year is recommended for adoption as official final action.

Simple Colorimetric Determination of Carrageenan in Jellies and Salad Dressings

1991 ◽  
Vol 74 (6) ◽  
pp. 1019-1022 ◽  
Author(s):  
Yoshie Yabe ◽  
Takahiro Ninomiya ◽  
Takashi Tatsuno ◽  
Taro Okada
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Alcian Blue ◽  
Coefficient Of Variation ◽  
Capillary Gas Chromatography ◽  
Colorimetric Method ◽  
Sample Solution ◽  
Colorimetric Determination ◽  
Chromatography Method

Abstract A simple, rapid colorimetric method is described for the determination of carrageenan (CAR) in foods such as jellies and salad dressings. Alcian blue reagent is added to the sample solution prepared from these foods, then CAR is precipitated selectively as a CAR-alcian blue complex. The precipitate is dissolved in monoethanolamine and determined colorimetrically at 615 nm. Overall recovery for jelly was 93.3% with a coefficient of variation (CV) of 5.8%. Overall recovery for salad dressing was 91.9% with a CV of 3.0%. The detection limit was 0.05%. The results obtained by the proposed method were similar to those obtained by a capillary gas chromatography method.

Collaborative Study of the Colorimetric Determination of Nitrate and Nitrite in Cheese

1976 ◽  
Vol 59 (2) ◽  
pp. 284-288
Author(s):  
James E Hamilton
Keyword(s):  
Azo Dye ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Sulfanilic Acid ◽  
Zinc Hydroxide ◽  
Colorimetric Determination ◽  
Standard Curve ◽  
Nitrite Nitrate ◽  
Nitrate And Nitrite

Abstract A quantitative colorimetric method for the determination of nitrate and nitrite in cheese has been subjected to collaborative study. The method includes clarification of an aqueous extract of cheese with zinc hydroxide, reduction of nitrate to nitrite via a spongy cadmium column (the nitrite originally present is unaltered), diazotization of sulfanilic acid with the nitrite, and coupling with 1-naphthylamine hydrochloride to form a pink azo dye whose absorbance is measured at 522 nm. The spectrophotometric responses are compared to a standard curve. In samples containing both nitrate and nitrite, nitrate is determined by difference. A standard deviation of 5.5 was obtained (5 of 6 collaborators) when a cheese sample spiked with 276 ppm sodium nitrate was analyzed by the method. The method has been adopted as official first action.

Colorimetric Determination of Selenium in Premixes and Supplements

1992 ◽  
Vol 75 (2) ◽  
pp. 269-271 ◽  
Author(s):  
Jeffrey A Hurlbut ◽  
Roger G Burkepile ◽  
Carolyn A Geisler
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Coefficient Of Variation ◽  
Colorimetric Method ◽  
Colorimetric Determination ◽  
High Concentrations

Abstract A colorimetric method Is described for the determination of 100-10 000 μg selenlum/g premix. Selenium Is present in premixes as either selenite or selenate. Moderate to high concentrations of several common minerals are tolerated. The premix is briefly digested In a sulfuric acid-perchloric acidsodium molybdate mixture, boiled in 10% NaCI solution, made basic, and centrifuged. Aliquots are taken if necessary. The mixture Is then acidified with formic acid, treated with hydroxylamlne hydrochlorlde- EDTA, and complexed with 3,3 - dlamlnobenzldlne. The pH Is adjusted, and an extraction Is performed with toluene. The absorbance is measured at 420 nm. Recoveries for 100- 10 000 μg selenlum/g premix ranged from 88 to 104%, with an average of 97%. The coefficient of variation ranged from 1.6 to 6.9%, with an average of 4.2%.

Collaborative Study of a Colorimetric Determination of Nitrate in Tobacco

1969 ◽  
Vol 52 (4) ◽  
pp. 756-759
Author(s):  
C James Rosene
Keyword(s):  
Sulfuric Acid ◽  
Standard Deviation ◽  
Systematic Error ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Water Soluble ◽  
Colorimetric Determination ◽  
Error Standard Deviation

Abstract A colorimetric method for determining water-soluble nitrate in tobacco was studied by 14 laboratories on eight Burley and two cigar filler tobacco samples with nitrate levels of 0.5–2.4%. In the method, ground tobacco is extracted with water and filtered, and an aliquot is then treated with 2,4-xylenol in sulfuric acid; then the resulting 6-nitro-2,4-xylenol is removed by distillation and measured spectrophotometrically at 450 µm. Results show that, althoughthe precision standard deviation among laboratories is generally acceptable, the systematic error standard deviation is unacceptably high. This study will be continued.

A Simple Automated Colorimetric Method for Determination of N-Acetyl- β-d-Glucosaminidase

1982 ◽  
Vol 19 (3) ◽  
pp. 157-159 ◽  
Author(s):  
Joan C Moore ◽  
Jacqueline E Morris
Keyword(s):  
Enzyme Activity ◽  
Calcium Chloride ◽  
Coefficient Of Variation ◽  
Colorimetric Method ◽  
Plasma Samples ◽  
Automated Method

An automated method for the determination of N-acetyl-β-d-glucosaminidase in serum or plasma using p-nitrophenol ( pNP) N-acetyl-β-d-glucosamine as substrate and a Pye Unicam AURA system is described. Normal samples had activities of 853 ± 146 (SD) nmol pNP liberated/ml/h, with intra-assay coefficient of variation 1·2% and inter-assay coefficient of variation 1·6%. Inhibition of enzyme activity by heparin in plasma samples can be reversed by the addition of calcium chloride to the buffer.

Improved Colorimetric Method for the Determination of Nitarsone in Feeds

1970 ◽  
Vol 53 (3) ◽  
pp. 641-645
Author(s):  
G M George ◽  
J L Morrison
Keyword(s):  
Nitro Group ◽  
Column Chromatography ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Average Recovery ◽  
Poultry Feeds ◽  
Average Coefficient ◽  
Medicated Feeds

Abstract An improved procedure for the determination of nitarsone in poultry feeds has been developed. The drug is extracted from feed with 50% dimethylsulfoxide; interferences are removed by column chromatography of the extract on alumina. The drug is eluted from the column with 4% NaOH and assayed colorimetrically with the Bratton-Marshall reaction after reduction of the nitro group with aqueous 4% titanous chloride. The average recovery of nitarsone from laboratory-medicated feed was 97.0% of theoretical with an average coefficient of variation of 3.4%. The method was applicable to both fresh feeds and feeds stored for periods up to 6 months. This method was subjected to a collaborative study for the determination of nitarsone in medicated feeds. The average recovery from 6 collaborators was 103.5% with an average coefficient of variation of 12.7%. Most of the collaborators reported satisfactory results and therefore this method is recommended for adoption as official first action.

Collaborative Study of the Colorimetric Determination of Zirconium in Antiperspirant Aerosols

1977 ◽  
Vol 60 (3) ◽  
pp. 663-668
Author(s):  
Paul Beavin
Keyword(s):  
Statistical Evaluation ◽  
Collaborative Study ◽  
Colorimetric Determination ◽  
Fusion Procedure ◽  
Coefficients Of Variation ◽  
Zirconium Compounds ◽  
Insoluble Form ◽  
Standard Deviations ◽  
Insoluble Compounds

Abstract A previously published method for determining zirconium in antiperspirant aerosols was collaboratively studied by 7 laboratories. The method consists of 2 procedures: a rapid dilution procedure for soluble zirconium compounds or a lengthier fusion procedure for total zirconium (soluble and insoluble compounds), followed by colorimetric determination. The collaborators were asked to perform the following: Spiking materials representing 4 levels of soluble zirconium were added to weighed portions of a zirconium-free cream base concentrate and the portions were assayed by the dilution procedure. Spiking materials representing 4 levels of zirconium in either the soluble or the insoluble form (or as a mixture) were also added to portions of the same concentrate and these portions were assayed by the fusion procedure. They were also asked to concentrate and assay, by both procedures, 2 cans each of 2 commercial aerosol antiperspirants containing zirconyl hydroxychloride. The average per cent recoveries and standard deviations for spiked samples were 99.8–100.2 and 1.69–2.71, respectively, for soluble compounds determined by the dilution procedure, and 93.8–97.4 and 3.09–4.78, respectively, for soluble and/or insoluble compounds determined by the fusion procedure. The average per cent zirconium found by the dilution procedure in the 2 commercial aerosol products was 0.751 and 0.792, respectively, with coefficients of variation of 2.94 and 2.53%, respectively. Insufficient collaborative results were received for the fusion procedure for statistical evaluation. The dilution procedure has been adopted as official first action.

Collaborative Study of the Colorimetric Determination of Sulfadimethoxine in Feeds

1970 ◽  
Vol 53 (3) ◽  
pp. 638-641
Author(s):  
M Osadca ◽  
E De Ritter
Keyword(s):  
Collaborative Study ◽  
Colorimetric Determination ◽  
Good Recovery ◽  
Drug Levels ◽  
Poultry Feeds ◽  
Extraction And Purification ◽  
Feed Samples

Abstract A method is described for determination of sulfadimethoxine in medicated poultry feeds. After extraction and purification of the extract, sulfadimethoxine is determined colorimetrically after diazotization and coupling with N-(l-naphthyl)ethylenediamine. The method was studied collaboratively by 11 laboratories on 4 feed samples containing graded drug levels. The method yields good recovery and precision and is recommended for adoption as official first action.

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