Abstract

UV-VIS SPECTROPHOTOMETRIC TECHNIQUE USED FOR THE DETERMINATION OF TRACE AMOUNT OF CU (II) IN HONEY COLLECTED FROM KIRTIPUR VILLAGE, KATHMANDU, NEPAL

*Surendra Prasad Singh, Ph.D.

ABSTRACT

Cu (II) ion is widely distributed in foods of plant tissue and animal organs. It is an essential trace element, but is also toxic in the environment. The determination of traces of copper has received considerable attention in the battle against environmental pollution. In order to assess its accumulation or deficiency in biological and environmental samples, sensitive and accurate analytical methods are required. Thus simply using 1-(2-pyridylazo)- 2-naphthal (PAN), as a new spectrophotometric reagent which is insoluble in water was developed to pre-concentrate traces of Cu (II) prior to their determination in honey samples collected from Kirtipur village by Uv-Vis Spectrophotometric technique. PAN reacts in highly acidic solution at pH 2.40 to 2.50 with Cu(II) to give a pink chelate which has an absorption maximum (λmax.) at 550nm. The reaction is instantaneous and absorbance remains stable for over 48hrs. The average molar absorption coefficient (ε) was found to be 2.05×10 4 L mol-1 cm-1 and Sandell sensitivity was 3.23×10−4μg cm-2. UV visible spectrophotometer is cost effective and available in almost all laboratories and the complexes of PAN in aqueous solutions are not reported so far and this is the first attempt in Nepalese context of spectrophotometric analysis. The Procedure developed was applied for the estimation of copper in microgram quantities in the samples of alloys and the method was found to be simple, rapid and comparable to routine analytical methods for trace level analysis of metal ions in environmental samples in any laboratory where sophisticated and expensive instruments are not available.

Keywords: Honey Trace analysis Cu (II), Cu-PAN, Uv-Vis Spectrophotometric technique, Nepal.