engleski

REMOVAL OF METAL POLUTANTS FROM ENVIRONMENTAL COTTON SAMPLES BY ULTRASOUND ASSISTED EXTRACTION

Ultrasonic extraction is today recognized as a useful method for analyte extraction from different biological and environmental samples. One of the first applications of ultrasonic extraction to metals dissolution for multi element analysis was performed by Harper et al. [1]. In his investigation, a NIST SRM was subjected to ultrasonic irradiation. In a more recent study, Sanchez et al. [2] investigated the use of UE for the analysis of metals in several European reference materials. Numerous other studies have demonstrated the usefulness of ultrasound for effective extraction and heavy metals single or multi element determination [3 – 9]. UE is fast, inexpensive, and efficient alternative to conventional leaching processes [4]. The industrial usage is spread from the food industry [9 -11] to the textile manufacturing with different applications: biopreparation [12], dyeing [13] , laundry [14] , and textile finishing [15]. It is expected that use of UE for sample preparation purposes in environmental analytical chemistry will become more widespread owing to its simplicity, ease of use, speed and enhanced safety when compared with other, more traditional sample preparation procedures [16]. Raw textile materials like cotton, flax or hemp contain different metals [17]. They may adsorb very large amounts of metals from the environment, depending on the growth conditions (soil, water and air) [18]. If plants are exposed to the high metal concentrations, it can be toxic for the plant, but at the same time they can be used as natural bio-absorbers [19]. Present metals contribute to problems in textile industry [20] in yarn manufacturing, bleaching and dyeing processes [21, 22]. If metals are present on clothing material, they may present a potential threat to human health [23]. This paper presents ultrasonic extraction efficiency results of 23 elements (Al, As, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Si, Sn, Tl, and Zn) extracted from standard cotton adsorptive material after previous adsorption. The prepared samples were extracted for 5 – 45 minutes in the ultrasonic bath, dried, wieged, and digested in the microwave owen under maximum temperature of 200 0C. The total concentration of metals in solutions colected after digestion was determined by inductively coupled plasma – optical emission spectrometry (ICP-OES). Better efficiency, less solvent consumption, shorter time of extraction and ecological as well as economical advantages of UE were proven on cotton material.

metal polutants; ultrasonic extraction

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