Analysis Of Phenanthroline Lab Report

METHOD OF ESTIMATION:

Iron (II) is quantitatively complexed with 1, 10- phenanthroline at pH 3 to 3.5 and forms orange-red color complex which is very stable. The intensity of color formed is directly proportional to the amount of iron in the sample therefore can be determined spectrophotometrically.

MATERIALS AND METHODS:

Instrumentation:

• All absorbance measurements will be conducted using UV-VIS Spectrophotometer (Shimadzu, UV mini-1240, Japan) and 1 cm matched plastic cuvettes.

• Weighing balance

• Hot plate

Apparatus:

• Volumetric flasks, conical flasks, beakers, and pipettes of borosilicate glass will be used in the study.

• Mortar and pestle for grinding the tablets.

Chemicals: (All reagents will be used without any further

H2Oup to the mark. If necessary warm slightly.

4. Preparation of stock solution of iron:

Weigh and transfer 0.07g of ferrous ammonium sulfate (Fe(NH4)2(SO4)2.6H2O) into a 1L volumetric flask, add water followed by 2.5mL of conc. H2SO4 and dilute to the mark with dist. H2O.The concentration of iron in the solution is 0.01 mg/ml

5. Preparation of working solutions of iron for calibration curve:

Into a series of 50-mL volumetric flasks add 5.0, 7.0, 10.0, 15.0 and 20.0 mL of the standard iron solution and 5 mL of dis. H2O to another 50 mL volumetric flask for a blank. Add 1 mL of hydroxylamine, 5 mL of sodium acetate, and 5 mL of orthophenanthroline to each flask. Allow the mixtures to stand for 5 min; dilute to the mark with dist. H2Oand mix well. Experiment will be performed in triplicate.

6. Method Validation:

The validation method will be performed as per International Conference on Harmonization (ICH) guidelines4.

6.1 Selection of analytical wavelength for iron-1, 10 –Phenanthroline complex:

One of the concentrations will be selected from working solutions prepared above (step 5) and will be scanned in the wavelength range of 400-600 nm for the absorbance values to get λmax and this wavelength willbe selected for the entire

6.5 Limit of detection (LOD) and Limit of Quantitation (LOQ):

LOD and LOQ will be calculated from the data obtained from the linearity studies. The slope (S) of the linearity plot will be determined, y intercept will be calculated and the standard deviation (σ) of the y intercept will be computed. From these values, LOD and LOQ will be determined using the following formulae.LOD = 3.3 × σ/S; LOQ = 10 × σ/S

6.6 Robustness:

It will be carried out by measuring absorbance of the concentration at three different wavelengths and results will be tabulated.

6.7 Ruggedness:

It will be carried out by recording absorbance of the concentration using two different instruments Shimadzu UV-1240, Sr. No. A109345-02720 and Shimadzu UV-1240, Sr. No. A109345-02722. The results will be reported as % RSD.

7. Estimation of Iron in different dosage