A differential spectrophotometric method for the determination of Grignard reagent concentration

The Analyst ◽  
1970 ◽  
Vol 95 (1133) ◽  
pp. 727-729 ◽  
Author(s):  
S. Görög ◽  
G. Szepesi
2003 ◽  
Vol 17 (1) ◽  
pp. 45-52 ◽  
Author(s):  
M. Jamaluddin Ahmed ◽  
Md. Shah Alam

A simple, sensitive and highly selective direct spectrophotometric method for the determination of trace levels of mercury(II) in various samples is described. Diphenylthiocarbazone (dithizone) reacts in slightly acidic 50% aqueous 1,4-dioxane media (0.18–1.80 M sulphuric acid) with mercury(II) to give an orange chelate which has an absorption maximum at 488 nm. The average molar absorption co-efficient and Sandell's sensitivity were found to be 2.5×104l mol−1 cm−1and 0.015 μg of Hg(II) cm−2, respectively. The reaction is immediate and absorbance remains stable for over 24 h. Beer's law is obeyed for concentration range of mercury(II) between 0.1 μg ml−1and 25 μg ml−1; the stoichiometric composition of the chelate is 1 :2 (mercury : dithizone). The various analytical parameters, such as effect of time, acidity, reagent concentration and foreign species, were studied. The method was applied successfully to a number of environmental waters (portable and polluted), biological samples (human blood, urine and fish), soils, plant samples (potato, cabbage, lettuce, carrot and tomato), solutions containing both mercury(I) and mercury(II) and complex synthetic mixtures. The method is very simple and requires no solvent extraction or pre-concentration steps.


Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.


2019 ◽  
Author(s):  
Chem Int

Recent study was conducted to develop a simple UV spectrophotometric method to determine Phenytoin in bulk and injection form according to official requirement and validate as per ICH guidelines. λmax of Phenytoin was found 202 nm. Linearity existed perceived in the concentration assortment 2-8 μg/ml (r2 = 0.999) for the method. The method was validated pertaining to linearity, precision and accuracy studies, LOD and LOQ consistent with ICH guidelines. The existent method was establish to be simple, linear, precise, accurate as well as sensitive and can be applied for routine quality control enquiry for the analysis of Phenytoin in bulk and injection form.


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