Theoretical aspects, instrumental devices and analytical applications of derivative ultraviolet-visible region absorption spectrophotometry are reviewed.

There are various methods for the analysis of Potassium Sorbate and Sodium Benzoate in food products, but a rapid and reliable method for identification of these preservatives in Doogh (an Iranian traditional dairy drink) is a procedure, in which high performance liquid chromatography (HPLC) utilized and followed by UV diode array detection of the two preservatives. The aim of this case study w...

Two simple and sensitive spectrophotometric and RP-HPLC methods are described for the determination of Olmesartan Medoxomil. The first method Spectrophotometry was based on the standard curve. Olmesartan Medoxomil exhibits λmax at 258 nm. Quantitative estimation of Olmesartan Medoxomil was carried out the standard calibration curve at 258 nm. The second method, high-performance liquid chromatog...

Bilirubin was determined by direct spectrophotometry and by the candidate reference method of Doumas et al. (Clin. Chem. (1985) 31; 1789-1798) in a group of more than 230 newborns, and the results were compared. Direct spectrophotometry by Vink et al. (Clin. Chem. (1988) 34; 67-70) gives the following regression equation in comparison with the reference method: y = 0.967x + 6.57 with r = 0.9874...

OBJECTIVES To compare the diagnostic accuracy of visual inspection and spectrophotometry for identifying the presence of bilirubin in the cerebrospinal fluid (CSF). METHODS Clinicians and students assessed CSF specimens with seven degrees of extinction between 0.00 and 0.09 at 450-460 nm as "yellow," "doubtful," or "colourless" after random presentation under standard conditions. The assessme...

Two methods, spectrophotometric and chromatographic-densitometric ones, were developed for determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations. Spectrophotometric method involved derivative spectrophotometry and zero order spectrophotometry. The measurements were carried out at lambda = 224.0 nm for quinapril, lambda = 261.0 nm for...

the acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. the stoichiometric equilibrium constants were determinedat 25 °c and constant ionic strength 0.1 mol l-1 (nacl). the acidity constants pk1=1.58±0.05and pk2=11.67±0.07 were found by potentiometry, and pk1=1.54±0.02 and pk2=11.61±0.03 bymulti-wavelengths spectrophotometry. potentiom...