removal of direct black 38 pigment using spe method by ldh al-zn from aqueous samples

The pigments (dyes) especially direct black 38 being utilized in industrial activities are considered as potential organic pollutants having adverse effect on the environment, human and animal health. hence, there is a fundamental need for identifying and treating environmental wastes [1]. solid phase extraction technique (spe) using different adsorbents is preferred for removal/ preconcentration of various analytes, due to its known advantages [2]. in recent years, layered-double hydroxides as tunable compounds have attracted the attentions of several researchers in different fields, including removal of various pollutants because of their advantages, such as relatively simple synthesis, non-toxicity, possessing a large specific surface area and high catalytic activity, biocompatibility [3]. in this research ldh al-zn with nitrate salt was synthesized, characterized and utilized as an adsorbent in the spe method to remove and purify water sample containing direct black 38 pigment, for the first time. uv-vis spectrophotometry as a simple and economical analytical technique rather than advanced analysis methods such as chromatography and electrophoresis was used for determination of analyte content in the samples. the effect of experimental parameters on the extraction efficiency was investigated and optimized as: sample ph=7, analyte concentration =5 mg/l, stirring rate = 300 rpm, equilibration time = 30 min. and adsorbent dose = 8 mg. under the optimal conditions the extraction efficiency for the pigment was found to be more than 97%.