New Colorimetric Determination of Fluoride

New Enzymatic Colorimetric Method for the Quantitative Determination of Phenylalanine in Dry-Blood Spots

Phenylketonuria (PKU) is an autosomal recessive disorder, which is characterized by severe mental retardation, microcephaly and seizures. The symptoms of this disease can be prevented if detected soon after birth. Therefore, blood Phenylalanine (Phe) measurement is essential for the early diagnosis, treatment and dietary monitoring of PKU patients. The goal of this research was to introduce a r...

Colorimetric Determination of Serum

In the past few years there has been renewed interest in the study of serum cholinesterase in various disease states, particularly those affecting the liver. Recently, a colorimetric method for the determination of this enzyme in the serum was reported by Ravin, Tsou, and Seligman (1). Their method, simple to perform, is as accurate as the gastrometric technique and more specific than the elect...

A new and rapid colorimetric determination of acetylcholinesterase activity.

A photometric method for determining acetylcholinesterase activity of tissue extracts, homogenates, cell suspensions, etc., has been described. The enzyme activity is measured by following the increase of yellow color produced from thiocholine when it reacts with dithiobisnitrobenzoate ion. It is based on coupling of these reactions: (enzyme) acetylthiocholine -----+ thiocholine + acetate thioc...

A new simple semimicro method for colorimetric determination of urea.

New colorimetric method for quantitative determination of protein in urine.

Total urinary protein is rapidly precipitated at room temperature by tannic acid. The tannic acid/protein precipitate, dissolved in aqueous triethanolamine/ferric chloride solution, gives a purple-violet color of high absorptivity. Absorbance at 510 nm is linearly related to concentration from 0.05 to 1.50 A for a protein content of 0.05 to 1.50 g/liter, and less than 5 mg/liter can be detected...