A rapid, simple and sensitive spectrophotometric method for the determination of trace amounts of chromium is studied. The method is based on the interaction of chromium with indigo carmine dye in acidic medium and the presence of oxalates as a catalyst for interaction, and after studying the absorption spectrum of the solution resulting observed decrease in the intensity of the absorption. As happened (Bleaching) for color dye, this palace and directly proportional to the chromium (VI) amount was measured intensity of the absorption versus solution was figurehead at a wavelength of 610 nm. A plot of absorbance with chromium (VI) concentration gives a straight line indicating that Beer’s law has been obeyed over the range of 0.5

       A rapid, simple and sensitive spectrophotometric method for the determination of trace amounts of chromium (VI) was studied. The method is based on the reaction of chromium (VI) with promethazine forming a red colored species by chromium in hydrochloric acid  medium  and exhibits  a maximum absorbance at 518 nm. A plot of absorbance with chromium (VI) gives a straight line indicating that  Beer’s law has been obeyed over the range concentration of 0.05-4.0 µg/ml with a molar absorptivity of chromium(VI) 2.04 ï‚´ 104       l.mol-1.cm-1 , Sandell’s sensitivity index of 0.0025 µg.cm-2  while the limit of detection (LOD) was found to be 0.0924 µg.ml

     A spectrophotometric method is proposed for the determination of some drugs containing amino group such as mesalazine, metoclopramide and dopamine in pharmaceutical formulations. It was simple, precise, accurate, rapid, and based on the oxidation of each drug with chromate as an oxidizing agent in the presence of 1N hydrochloric acid. Then indigo carmine is reacted with residual chromate in the presence of a catalysis factor (sodium oxalate). Increasing in absorbance's value of the color system is proportional to the amount of the three drugs which is measured at the selected wavelength of 610 nm.

The proposed method is obeying Beer's law in the ranges of (1-40, 2-44 and 2-52) ppm for the concentration of

     Twosimple, sensitive,accurate, and precise spectrophotometric methods have been developed for the determination of chlorpromazine – HCl in pure form and pharmaceutical formulation. The first method involved treatment of cited drug with a measured excess of permanganate in acid medium and the unreacted oxidant was measured at 525 nm. The second method involves the reaction  of the drug with potassium permanganate in the presence of sodium hydroxide to produce a bluish – green  colored manganite which is measurable at 610nm. All the experimental variables affecting the development of the manganite ions were investigatedand conditions were optimized. Working linearity ranges were 5-45 µg.mL-1an

A simple, precise, and sensitive spectrophotometric method has been established for the analysis of doxycycline. The method includes direct charge transfer complexation of doxycycline withp-Bromanil in acetonitrileto form a colored complex. The intensely colored product formed was quantified based on the absorption band at 377 nm under optimum condition. Beer’s law is obeyed in the concentration range of 1–50 μg.mL-1 with molar absorptivity of 1.5725x104 L.mol-1.cm-1, Sandell's sensitivity index (0.0283) μg.cm-2, detection limit of 0.1064 μg.mL-1, quantification limit 0.3224 μg.mL-1 and association constant of the formed complex (0.75x103). The developed method could find application in routine quality control of doxycycline and has

Ceftriaxone sodium were one of the widely antibacterial drugs used. Azo dye derivatization of diazonium salt that formed via the reaction between ceftriaxone with hydrochloric acid and sodium nitrite was developed for the on-research drug analysis then coupling with each one 2,5-dimethylphenol (2,5-DMP) and 4-tertbutylphenol (4-TBP) respectively in the alkaline media. The developed diazonium coupling methods include an optimization study. The results show a limit of detection and limit of quantification 0.482, 0.284 µg/mL, and 1.607, 0.945 µg/mL using 2,5-DMP and 4-TBP reagents respectively. Moreover, the recovery % obtained was 100.89%, and 103.37% at linear concentration range 3.0 – 50, and 10 – 30 µg/mL, with mo

Four rapid, accurate and very simple derivative spectrophotometric techniques were developed for the quantitative determination of binary mixtures of estradiol (E2) and progesterone (PRG) formulated as a capsule. Method I is the first derivative zero-crossing technique, derivative amplitudes were detected at the zero-crossing wavelength of 239.27 and 292.51 nm for the quantification of estradiol and 249.19 nm for Progesterone. Method II is ratio subtraction, progesterone was determined at λmax 240 nm after subtraction of interference exerted by estradiol. Method III is modified amplitude subtraction, which was established using derivative spectroscopy and mathematical manipulations. Method IIII is the absorbance ratio technique, absorba

A new spectrophotometric method for the determination of allopurinol drug was investigated. The proposed method was based on the reaction of the intended drug with catechol and Fe(II) to form a blue soluble complex which was measured at λmax 580 nm. A graph of absorbance versus concentration shown that Beer’s law was obeyed over the concentration range of 2–10 μg ml–1 with molar absorptivity of 9.4 x 103 l mol–1 cm–1 and Sandell sensitivity of 1.4 x 10–2 μg cm–2. A recovery percentage of 100% with RSD of 1.0%–1.3% was obtained. The proposed method was applied successfully for the determination of allopurinol drug in tablets with a good accuracy and

Flow-injection (FI) spectrophotometric method has been developed for the analysis of thymol in pharmaceutical preparations. The method is based on organic coupling reaction between thymol and 4-amino antipyrine in the presence of alkaline medium to form an intense stable red color complex with copper nitrate that has a maximum absorption at 490 nm. Optimum conditions for determination of the drug was investigated .The calibration graph was linear over the range of 5-500 µg.ml-1 of thymol . The limit of detection (LOD) and limit of quantification (LOQ) were 1.81 ?g mL-1 and 3.60 ?g mL-1 respectively .The proposed method was applied satisfactorily to the determination of thymol in mouth wash preparations. The procedure is characterized by