Some important metallic constituents in juice of watermelon

The juice of different watermelon samples has been studied for some metallic constituents by Atomic Absorption Spectrophotometer. The syrup of watermelon samples has been evaluated by keeping in view of its usefulness for eating purposes. The sodium and potassium were determined by flame photometry. The potassium content has been found more than 800 ppm in all samples whereas sodium content has been approximately 200 ppm. The other metallic [Ni, Cd, Cu, Zn, Fe, and Mn] constituents have been low in concentration. This low concentration in liquor is also useful for human beings. Zn concentration was higher among these low constituents; whereas cadmium was lowest in detectable limits

measurement of turbidity by changing distance of sample column from light source

Turbidity of the known standards have been measured by changing the- distance of sample column from light source with the help of cell risers in the cell compartment. The cell risers of 10, 20, 30, 40, 50, 60, 70, and 80 mm were used to reduce the light path-length between the bottom of the sample cell and the detector window when measuring the turbidity of the known standard 1 to 5 Nephelometric Turbidity Units [NTEJ]. The data indicate that at above 50 mm cell riser the results were matched with the actual one

Plant leaves as a pH indicator

Extract of leaves of Amrood [Psidium guajava], Eucalyptus which have same classifications and Anar [Punica granatum] with same order [Myrtales] but different family and Shisham [Dalbergia Sissoo Roxb. or Sisu] and Hibiscus with different order have been obtained and their behaviour observed in acid or basic medium as a function of colour change, i.e. acid-base indicator. The extract of these leaves, which are highly coloured, act, as pH indicator. The indicator constant [pK1n] for the extract of these leaves was found to be 7.3 pH range 6.3 to 8.3 and K1n was 5 x 10[-8]