Improved method of nitrogen determination by indophenol reaction

An improved HPLC method for determination of colocynthin in colocynth

Background and objectives: Colocynthin is the major active secondary metabolite of colocynth, Citrullus colocynthis (L.) Schrad, which has been used in traditional and ethno medicine of many countries.  It could be considered as an active marker for quality control of colocynth and its herbal products. Analysis and standardization of colocynth and its herbal preparations are a critical...

Indophenol method for acetaminophen in serum examined.

We show that an indophenol-based colorimetric method for acetaminophen (Clin Toxicol 15: 67-73, 1979) has less than maximal sensitivity because of (a) incomplete hydrolysis, related to suboptimal acid concentration; (b) suboptimal hydrolysis time; and (c) possible deterioration of the ammonium hydroxide reagent after 2.5 months. We have modified the method by optimizing duration of hydrolysis a...

SPECTROPHOTOMETRIC REACTION RATE METHOD FOR THE DETERMINATION OF NITRITE BY CATALYTIC ACTION ON NILE BLUE A BROMATE REACTION

A kinetic method developed for the determination of ultra-trace amounts of nitrite based on its catalytic effect on the reaction between potassium bromate and Nile blue A in strongly acidic media is reported. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of Nile blue A at 645 nm by the fixed-time method. The decrease in absorbance during the first...

The Determination of Ascorbic Acid as Furfural and a Comparison of Results Obtained by This Method and by Indophenol Titration

multiwavelength pectrophotometric determination of stability constants of 4-(2– thiazolylazo) resorcinol (tar) with la3+, y3+ and th4+ in organic-water mixed solvents by chemometrics method & simultaneous spectrophotometric determination of lead, copper and nickel using xylenol orange by partial least squares calibration method

تشکیل کمپلکس های tarبا یون های لانتانیم, ایتریم و توریم در دمای 25 درجه، قدرت یونی ثابت 0.1 مولار و در ph ثابت در مخلوط حلال های اتانول – آب و استونیتریل – آب با استفاده از روش های اسپکتروفوتومتری مورد بحث و بررسی قرار گرفت. داده های اسپکتروفوتومتری با استفاده از نرم افزار squad پردازش شدند تا ثابت های تشکیل کمپلکس اندیکاتور – فلز را محاسبه کند. نتایج نشان می دهد که درصد حلال آلی در مخلوط حلال ...