Continuous ultrasound-assisted extraction of cadmium from legumes and dried fruit samples coupled with on-line preconcentration-flame atomic absorption spectrometry

Abstract

Cadmium was continuously extracted with diluted nitric acid from legumes and dried fruit samples using a simple, rapid and continuous ultrasound-assisted extraction system. A minicolumn packed with a chelating resin (Chelite P, with aminomethylphosphoric acid groups) was placed between the extraction unit and the detector for cadmium preconcentration. The cadmium content in the acid extract was retained into the minicolumn, and elution was carried out with hydrochloric acid, with this trace metal continuously monitored by flame atomic absorption spectrometry. An experimental design (Plackett-Burman 2(6) x 3/16) was used to optimize the continuous leaching procedure and the preconcentration step. The method allowed a total sampling frequency of 10 and 14 samples per hour for legumes and dried fruit, respectively. The procedure displayed good precision (2.0 and 2.5%, respectively, expressed as relative standard deviations) for samples containing 0.202+/-0.005 microg g(-1) Cd (broad bean) and 0.239+/-0.004 microg g(-1) Cd (peanut). Detection limits of 0.014 microg g(-1) Cd for 60 mg of legume samples and 0.011 microg g(-1) Cd for 80 mg of dried fruit samples were obtained. The method was successfully applied to the determination of trace amounts of cadmium in legumes and dried fruit samples.

Mineral characterization of native fruits from the southern region of Brazil

“…Ca is an essential mineral in the formation and maintenance of bones and teeth. This mineral is also involved in the transport of cellular membranes, the activation or release of enzymes, muscle contractions, and the transmission of nerve impulses (regulating the heartbeat) (Yebra & Cancela, 2005 (Ekholm et al, 2007) had higher levels of this mineral compared with those of the fruit samples examined in the present study.…”

Trace metal contents in chewing gums and candies marketed in Turkey

“…Many different studies and methods for heavy metal determination in different food stuffs have been reported in the literature including dry, wet and microwave digestion methods to investigate heavy metal levels in cheese, fruits, fruit juices, vegetables, sweets, chocolates, honey, snacks, appetizers, etc. (Soylak et al 2006;Radwan and Salama 2006;Zahoor et al 2003;Yebra and Cancela 2005;Nascentes et al 2004;Saracoglu et al 2004). Sweets including chewing gums and candies are not exactly a food, but it is especially consumed by children and pregnant woman with ingesting or chewing by teeth in mouth.…”

Experimental Design Techniques for Optimization of Analytical Methods.Part II: Spectroscopic and Electroanalytical Techniques

“…Other studies regarding the optimization of ultrasound assisted extraction for the on line determination of cadmium from legumes and dried fruit samples were proposed by Yebra et al [17,18]. In these papers, Cd was continuously extracted with diluted acid using a continuous ultrasoundassisted extraction system (CUES).…”

“…In the last years chemometric approaches have been applied also for optimization of analytical methods based on the use of atomic spectroscopic techniques in the environmental [1][2][3][4][5][6][7][8][9][10] and food area [11][12][13][14][15][16][17][18][19][20][21].…”