Collaborative Study of Colorimetric Determination of Aluminum, Iron, Manganese, Phosphorus, and Titanium in Liming Materials with Supplementary Reports on Methods for Silicon

1964 ◽  
Vol 47 (6) ◽  
pp. 1019-1027
Author(s):  
P Chichilo
Keyword(s):  
Collaborative Study ◽  
Colorimetric Determination ◽  
Aluminum Iron ◽  
Standard Deviations ◽  
Iron Manganese

Abstract The following determinations were studied collaboratively: Al with ammonium aurintricarboxylate (Aluminon); Fe with 2,4,6-tripyridyl-s-triazine (TPTZ); Mn by oxidation to permanganate with KI04; P by a heteropoly blue method; and Ti with disodium-1,2-dihydroxybenzene-3,5-disulf onate (Tiron). Sample solutions were prepared by HCIO4 digestion or NaOH fusion. Reports were received from 11 collaborators. Eight of these reported all 5 elements, 2 reported 4 elements, and 1 reported 2 elements. Eight collaborators also reported Si. Standard deviations and mean errors are acceptable, and it is recommended that the methods be adopted as official, first action.

Colorimetric Determination of the Progestational Steroids in Contraceptive Tablets

1970 ◽  
Vol 53 (4) ◽  
pp. 831-833
Author(s):  
John Y P Wu
Keyword(s):  
Oral Contraceptive ◽  
Medroxyprogesterone Acetate ◽  
Collaborative Study ◽  
Chloroform Extract ◽  
Colorimetric Determination ◽  
Standard Deviations ◽  
Isonicotinyl Hydrazide ◽  
Norethindrone Acetate

Abstract Norethindrone, norethindrone acetate, dimethisterone, medroxyprogesterone acetate, and norethynodrel are determined in oral contraceptive tablets. For the first 4 compounds, a chloroform extract of the tablets is treated directly with isonicotinyl hydrazide reagent to produce a stable color which is measured at 380 nm. The chloroform extract of norethynodrel tablets is isomerized before the reagent is added. An intralaboratory study gave good results, with standard deviations of 0.74 to 1.21%. A collaborative study is recommended.

Sulfuric Acid/Hydrogen Peroxide Digestion and Colorimetric Determination of Phosphorus in Meat and Meat Products: Collaborative Study

1991 ◽  
Vol 74 (1) ◽  
pp. 22-26 ◽  
Author(s):  
David K Christians ◽  
Thomas G Aspelund ◽  
Scott V Brayton ◽  
Larry L Roberts
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Collaborative Study ◽  
Meat Products ◽  
Colorimetric Determination ◽  
Pork Sausage ◽  
Relative Standard ◽  
Significant Difference ◽  
Standard Deviations

Abstract Seven laboratories participated In a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested In sulfuric acid and hydrogen peroxide; digestion Is complete In approximately 10 mln. Phosphorus Is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (sR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations Indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

Collaborative Study of a Colorimetric Determination of Benztropine Mesylate in Tablets and Injections

1973 ◽  
Vol 56 (3) ◽  
pp. 681-683
Author(s):  
Marshall C Stricklin
Keyword(s):  
Collaborative Study ◽  
Dosage Forms ◽  
Bromophenol Blue ◽  
Colorimetric Determination ◽  
Standard Deviations ◽  
Concentration Levels

Abstract A collaborative study was conducted on simulated tablet and injection preparations at 2 concentration levels each and a 20 tablet composite of a tablet simulating presently marketed dosage forms of benztropine mesylate. Analysis involves the extraction of benztropine from 0.2N H2SO4 with bromophenol blue in CHCl3. Absorbance of the dye complex formed is measured at about 410 nm. Average recoveries and standard deviations submitted were: 98.9±2.54 and 99.2±2.58, 100.1±2.78 and 100.0±2.19, and 100.1±2.23%, respectively. The method has been adopted 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.

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 Spectrophotometric Determination of Procainamide Hydrochloride

1976 ◽  
Vol 59 (4) ◽  
pp. 807-810
Author(s):  
Jeffrey C Hamm
Keyword(s):  
Sodium Hydroxide ◽  
Acid Medium ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Dosage Forms ◽  
Standard Deviations

Abstract The USP analysis for procainamide HCl is titrimetric and relatively nonspecific, capsule and tablet dyes may interfere, and the method is not applicable to coated tablets. In the spectrophotofluorometric method the sample deteriorates when exposed to a xenon source. In the ultraviolet spectrophotometric method reported here, the sample is dispersed in acid medium, possible interferences are extracted in chloroform, base is added, procainamide is extracted in chloroform, the residue is dissolved in sodium hydroxide, and the compound is measured by absorption at 272 nm and comparison with a standard. Recoveries of standards added to capsule, tablet, and injection composites ranged from 99.3 to 102%. Twelve collaborators reported duplicate assay results for all 3 dosage forms with per cent standard deviations for 5 samples ranging from 1.01 to 1.27%. The method has been adopted as official first action.

Quantitative Ultraviolet Determination of Amiben in Dry Granular and Liquid Formulations: Collaborative Study

1970 ◽  
Vol 53 (6) ◽  
pp. 1155-1159
Author(s):  
Joax W Brunstad
Keyword(s):  
Sodium Salt ◽  
Collaborative Study ◽  
Standard Deviations

Abstract Amiben is determined as the sodium salt in 1% NaOH at 297 nm. Prepared materials and technical formulations containing 0-60 μg amiben/ml were analyzed in a collaborative study. Standard deviations for technical samples ranged from 0.05 to 0.45 and for prepared samples from 0.02 to 0.35. The method is recommended for adoption as official first action.

Collaborative Study of the Gas-Liquid Chromatographic Method for Determination of Stereochemical Composition of Amphetamine

1972 ◽  
Vol 55 (1) ◽  
pp. 146-148
Author(s):  
Clyde E Wells
Keyword(s):  
Column Chromatography ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Good Precision ◽  
Liquid Chromatographic Method ◽  
Precision And Accuracy ◽  
Standard Deviations ◽  
Liquid Chromatographic ◽  
Amphetamine Sulfate

Abstract Eight laboratories collaboratively studied a method for the quantitative GLC determination of d- and l-amphetamine in tablets. The drugs are separated from tablet excipients by column chromatography and reacted with Ntrifluoroacetyl-( 0-prolyl chloride, and the resulting derivatives are analyzed by GLC. The samples consisted of commercial d-amphetamine sulfate tablets (with and without butabarbital), dl-amphetamine sulfate tablets, and a mixed d- and l-amphetamine sulfate standard. Recoveries were acceptable, and the standard deviations never exceeded 0.64%. The results demonstrate that the method gives good precision and accuracy, and the method is recommended for adoption as official first action.

scholarly journals Determination of Ochratoxin A in Wine and Beer by Immunoaffinity Column Cleanup and Liquid Chromatographic Analysis with Fluorometric Detection: Collaborative Study

2001 ◽  
Vol 84 (6) ◽  
pp. 1818-1827 ◽  
Author(s):  
Angelo Visconti ◽  
Michelangelo Pascale ◽  
Gianluca Centonze ◽  
E Anklam ◽  
A M Betbeder ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Red Wine ◽  
Collaborative Study ◽  
White Wine ◽  
Fluorometric Detection ◽  
Immunoaffinity Column ◽  
Relative Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract The accuracy, repeatability, and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine, and beer were established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked, and naturally contaminated materials at levels ranging from ≤0.01 to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, and the diluted samples were filtered and cleaned up on an immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine, and beer ranged from 88.2 to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3 to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL), and from 87.0 to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6 to 10.8% for white wine, from 6.5 to 10.8% for red wine, and from 4.7 to 16.5% for beer. Relative standard deviations for between-laboratories reproducibility (RSDR) ranged from 13.1 to 15.9% for white wine, from 11.9 to 13.6% for red wine, and from 15.2 to 26.1% for beer. HORRAT values were ≤0.4 for the 3 matrixes.

Collaborative Study of the Determination of Phosphorus in Gelatin, Dessert Preparations, and Mixes

1972 ◽  
Vol 55 (3) ◽  
pp. 581-582
Author(s):  
Roger G Burkepile
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Standard Samples ◽  
Preliminary Work ◽  
Aoac Method ◽  
Standard Deviations

Abstract A collaborative study of the proposed method for phosphorus in gelatin, dessert preparations, and mixes has been conducted. The present AOAC method for phosphorus in fertilizers, 2.023–2.025(a), was modified for this study. Preliminary work by the Associate Referee involving 4 phosphorus standard samples compared the proposed method with the official final action AOAC method for gelatin, 23.004. Additionally, phosphorus standard spikes in gelatin at the 1 and 10 mg P2O5, levels were determined by the proposed method. The proposed method is faster and more sensitive than the official method and is as accurate. Five collaborators and the Associate Referee analyzed 4 prepared samples containing various levels of phosphorus by the proposed method. The standard deviations varied from 0.005 for a 225 Bloom gelatin containing an average of 0.273% P2O5 to 0.016 for a strawberry-flavored commercial gelatin with added lecithin containing an average of 0.110% P2O5. The proposed method has been adopted as official first action to replace 23.004, which was repealed, official first action.

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