Spectrophotometric determination of phenol by the 4-aminoantipyrine method after steam distillation in a semimicro kjeldahl apparatus in the presence of a large amount of sodium chloride

The previous observation by Stillings and Browning that methylfurfural and hydroxymethylfurfural do not interfere with the photocolorimetric determination of furfural with aniline has been confirmed. The color of the furfural – aniline acetate compound was stabilized satisfactorily by oxalic acid and sodium chloride; the addition of disodium phosphate brought about minimum transmittance. Recoveries of furfural distilled from 12% hydrochloric acid were 99.0 and 99.7% as measured by the photocolorimetric and excess bromine titration methods respectively. Xylose was converted to furfural in 90.6% yield by simple distillation with 12% hydrochloric acid saturated with sodium chloride. Rapid steam distillation increased the recovery to 91.6%. Dextrose, levulose, cellulose and rhamnose gave apparent furfural yields by the excess bromine titration method but negative results with the photocolorimetric method. The two methods were applied to 13 plant residues whose furfural contents ranged from more than 30% in 'Beewing' wheat bran to less than 5% for peat. The results obtained by the photocolorimetric method, regarded as being the true furfural contents, are 2 to 3% lower than those obtained by the titration method.

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Quantitative determination of Levomepromazine in pharmaceuticals by spectrophotometric method as its sulfoxide

French-Ukrainian Journal of Chemistry ◽

10.17721/fujcv8i1p117-124 ◽

2020 ◽

Vol 8 (1) ◽

pp. 117-124

Author(s):

Olena Mozgova ◽

Mykola Blazheyevskiy

Keyword(s):

Sodium Chloride ◽

Citric Acid ◽

Quantitative Determination ◽

Spectrophotometric Determination ◽

Spectrophotometric Method ◽

Present Method ◽

Limit Of Quantification ◽

Derivatizing Agent ◽

Sensitive Method

The oxidative derivatization method using Diperoxyazelaic acid for the indirect spectrophotometric determination of Levomepromazine hydrochloride is presented. Diperoxyazelaic acid is introduced as a derivatizing agent for Levomepromazine, yielding the sulfoxides. This reaction product was successfully used for the spectrophotometric determination of the Levomepromazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Levomepromazine hydrochloride in the concentration range of 3-150 µg/mL. The limit of quantification, LOQ (10S) is 2.85 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Levomepromazine in Tisercin Solution for Injection 25mg/mL was demonstrated. The present method is precise, accurate and other excipients: anhydrous citric acid, monothioglycerol, sodium chloride did not interfere. RSD = 1.24 % (δ = –0.02 %).

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