Enzymatic method for selective determination of 4-aminobenzoic acid in urine.
نویسندگان
چکیده
We developed a method for the selective determination of 4-aminobenzoic acid by use of 4-aminobenzoate hydroxylase (EC 1.14.13.27) to convert 4-aminobenzoic acid to 4-hydroxyaniline. The subsequent conversion of 4-hydroxyaniline to indophenol dye was quantified colorimetrically. The method is reproducible, and the assay response is linear up to 40 mumol/L. Selectivity exceeding that of the current colorimetric assays was demonstrated for these enzymatic determinations of 4-aminobenzoic acid concentrations in urine samples from patients undergoing tests of pancreatic function with bentiromide. This method effectively minimizes interferences from drugs and diet, a problem in current colorimetric methods.
منابع مشابه
Determination of p-aminobenzoic acid in urine by room-temperature phosphorimetry, with application to the bentiromide test for pancreatic function.
Analytical recovery of urinary p-aminobenzoic acid liberated from bentiromide(N-benzoyl-L-tyrosyl-p-aminobenzoicacid) was determinedby roomtemperaturephosphorimetryas an index to exocrine pancreatic function. Metabolites were hydrolyzed to the parent compound in 4 mol/L NaOH, then quantified, after pH adjustment, by spothng 3 L of this solution onto filter paper treated with potassium iodide an...
متن کاملSimultaneous Adsorptive Stripping Differential Pulse Voltammetric Measurements of Trace Lead, Cadmium and Nickel in the Presence of 2-aminobenzoic Acid
In this study, 2-aminobenzoic acid (ABA) has been used as complexing ligand for simultaneousdetermination of metal ions by adsorptive cathodic stripping voltammetry (AdCSV), for the firsttime. Thus, a selective and sensitive procedure was presented for simultaneous determination oflead, cadmium and nickel using ABA and differential pulse-adsorptive cathodic strippingvolt...
متن کاملSimple spectrofluorometric determination of p-aminobenzoic and p-aminosalicylic acids in biological fluids by use of terbium-sensitized luminescence.
A novel, sensitive, and selective method has been developed for determination of p-aminobenzoic (PABA) and p-aminosalicylic (PAS) acids in the N-benzoyl-L-tyrosyl-PABA/ PAS test. PAS is measured as a ternary complex with terbium and EDTA (lambda(ex) = 324 nm, lambda(em) = 546 nm) in alkaline aqueous solution (pH approximately 12.6), whereas both compounds (PABA and PAS) are measured as ternary ...
متن کاملElectropolymerization of 4-aminobenzoic acid containing nano-Au deposited on carbon paste electrode for determination of acetaminophen
The conducting polymer films have been widely applied in the field of electrochemistry owing to their goodstability, permselectivity, unique physical and chemical properties. A novel nano-Au/poly (4-aminobenzoicacid) (PABA) film modified carbon paste electrode was fabricated for sensitive detection of acetaminophenin this paper. The PABA film and nano-Au/PABA film were characterized by scanning...
متن کاملSelective Spectrophotometric Determination of Metformin Hydrochloride in Pharmaceuticals and Urine Using Two Nitrophenols as Chromogenic Agents
Metformin hydrochloride (MFH) is an oral anti-diabetic drug of biguanide class. Two selective spectrophotometric methods were presented for the determination of MFH in pharmaceuticals. The methods were based on the measurement of yellow-coloured charge-transfer complexes formed between MFH and two poly-nitrophenols, namely, 2,4-dinitrophenol (DNP method, at 405 nm) and picric acid (PA met...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Clinical chemistry
دوره 36 11 شماره
صفحات -
تاریخ انتشار 1990