Improved Extraction Method for the Determination of Fe,Cu,Zn,and Ni in Fat Samples Using Atomic Absorption Spectrophotometer

摘要

The present work dealt with a rapid,ultrasonically assisted acid extractive method applicable for the determination of iron,copper,nickel and zinc in margarine and shortening samples using the atomic absorption Spectrophotometer as analytical tool.The percent recovery of Cu,Fe,Ni and Zn was found to be 96.45-97.08,96.5-97.85,95.8-97.5 and 96.0-97.8 % as compared with the conventional extraction method of 80.52,81.94,84.09 and 85.68% respectively,in the margarine and shortening samples which were fortified with 0.0,0.125,0.25,0.5,1.0 and 2.0 mug/gm of each metal ion using the standard addition method.The use of ultrasonic intensification in the present method reduced the conventional acid extraction time from 180 to 10 minutes only,with detection limit achieved down to nanomole level.Most of the investigated samples of different brands were found contaminated with notable amount of iron and nickel ranged 0.52 to 2.38 mug /g and 0.0.41 to 3.40 mug/g respectively.The magnitude of occurrence for copper and zinc was low within the range of 0.03-0.08 mug/g.Results of the proposed method were also found in complete agreement to those of wet digestion method and showed very good statistical correlation with coefficient of variation below 2.2%.