A new procedure for determination of the acid and base strength distribution of colored catalysts

1980 ◽  
Vol 15 (1) ◽  
pp. 9-12
Author(s):  
J. Adamiec
Keyword(s):  
Strength Distribution ◽  
Acid And Base ◽  
Base Strength

Bestimmung von Oberflächenoxiden auf Rußen durch potentiometrische Direkttitration in nichtwäßrigen Lösungsmitteln / Determination of Surface Oxides on Carbon Blacks by Direct Potentiometric Titration in Non-Aqueous Solvents

1990 ◽  
Vol 45 (6) ◽  
pp. 857-863
Author(s):  
J. O. Besenhard ◽  
H. P. Gansmann ◽  
H. Meyer
Keyword(s):  
Aqueous Media ◽  
Acid Strength ◽  
Strength Distribution ◽  
Fast Method ◽  
Carbon Blacks ◽  
Direct Titration ◽  
Surface Oxides ◽  
Acid And Base ◽  
Base Strength

An attempt is made to quantitatively determine acidic and basic surface oxides on carbon blacks and also to monitor their acid and base strength distribution by direct potentiometric titrations in non-aqueous media.In contrast to direct titration procedures proposed so far, our method allows to distinguish clearly between several types of acidic surface oxides of different acid strength. This is mainly achieved by improvements of the non-aqueous titration media. The total contents of weakly and strongly acidic and also of basic oxides determined by this very fast method is comparable to results obtained by slow and laborious indirect titrations.

Determination of Cobalt in Fertilizers

1965 ◽  
Vol 48 (2) ◽  
pp. 412-415
Author(s):  
J F Hodgson ◽  
Victor A Lazar
Keyword(s):  
Colorimetric Method ◽  
Isoamyl Acetate ◽  
Acid Mixture ◽  
Acid And Base ◽  
Colorimetric Methods

Abstract Cobalt in fertilizers was determined by a colorimetric method using 2-nitroso-l-naphthol. With this method the fertilizer is digested with a ternary acid mixture; cobalt is then extracted from a suitable aliquot into isoamyl acetate at pH 8.5 with an excess of 2-nitroso-l-naphthol. Excess dye and interferences are removed by successive washes with acid and base. A limited number of collaborator analyses indicate that agreement of results is not as satisfactory as might be expected with the major fertilizer constituents. However, collaborator agreement compares favorably with other methods of analyses accepted by the AOAC for Co. While the procedure is considered tedious by some collaborators, it is believed to be less tedious and less subject to interferences than other colorimetric methods available.

scholarly journals Stability-Indicating Validated HPLC Method for Simultaneous Determination of Oral Antidiabetic Drugs from Thiazolidinedione and Sulfonylurea Groups in Combined Dosage Forms

2010 ◽  
Vol 93 (4) ◽  
pp. 1086-1092 ◽  
Author(s):  
Anna Gumieniczek ◽  
Anna Berecka ◽  
ukasz Komsta
Keyword(s):  
Simultaneous Determination ◽  
Mobile Phase ◽  
Uv Light ◽  
Degradation Products ◽  
Dosage Forms ◽  
Hplc Method ◽  
Base Temperature ◽  
Stability Indicating ◽  
Acid And Base

Abstract For type 2 diabetes treatment, combinations of drugs from the thiazolidinedione and sulfonylurea groups are now available in the same tablet or capsule. Therefore, a stability-indicating and validated HPLC method was developed for simultaneous determination of pioglitazone, rosiglitazone, and glipizide in combined dosage forms. The examined drugs were subjected to different conditions such as acid and base, temperature, and UV light, and degradation of pioglitazone and glipizide was observed under thermal and acidic stress. However, selectivity of the presented method for pioglitazone, rosiglitazone, and glipizide assay against their degradation products was confirmed. It was also demonstrated to be robust, resisting small deliberate changes in pH of the buffer, flow rate, and percentage of acetonitrile in the mobile phase. The presented method utilizes a LiChrospher RP18 column (125 4.0 mm), acetonitrile in phosphate buffer at pH 4.3 (40 + 60, v/v) as the mobile phase, and UV detection at 225 nm for pioglitazone/glipizide or 245 nm for rosiglitazone/glipizide. The method was validated with respect to linearity, precision, and accuracy. Finally, the elaborated procedure was applied for the QC of pioglitazone/glipizide and rosiglitazone/glipizide mixtures.

Determination of strength distribution of quasibrittle structures from mean size effect analysis

2013 ◽  
Vol 66 ◽  
pp. 79-87 ◽  
Author(s):  
Jia-Liang Le ◽  
Augusto Cannone Falchetto ◽  
Mihai O. Marasteanu
Keyword(s):  
Size Effect ◽  
Strength Distribution ◽  
Effect Analysis ◽  
Mean Size

Determination of single fibre strength distribution from fibre bundle testings

1984 ◽  
Vol 19 (10) ◽  
pp. 3319-3324 ◽  
Author(s):  
Zhifan Chi ◽  
Tsu -Wei Chou ◽  
Guoyi Shen
Keyword(s):  
Fibre Bundle ◽  
Single Fibre ◽  
Strength Distribution ◽  
Fibre Strength
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