Comparison Studies on Several Ligands Used in Determination of Cd(II) in Rice by Flame Atomic Absorption Spectrometry after Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction

Abstract

Ligands plays an important role in the extraction procedures for the determination of cadmium in rice samples by using flame atomic absorption spectrometry (FAAS). In the present study, comparative evaluation of 10 commercially available ligands for formation of Cd(II)-ligand complex and determination of cadmium in rice samples by ultrasound-assisted dispersive liquid–liquid microextraction (UADLLME) combined with FAAS was developed. Sodium diethyldithiocarbamate (DDTC) provided a high distribution coefficient as well as a good absorbance signal, therefore DDTC was used as a ligand in UADLLME. A low density and less toxic solvent, 1-heptanol, was used as the extraction solvent and ethanol was used as the disperser solvent. In addition, the experimental conditions of UADLLME were optimized in standard solution first and then applied in rice, such as the type and volume of extractant and dispersant, pH, extraction time, and temperature. Under the optimal experimental conditions, the detection limit (3σ) was 0.69 μg/L for Cd(II). The proposed method was applied for the determination of Cd(II) in three different rice samples (polished rice, brown rice, and glutinous rice), the recovery test was carried out, and the results ranged between 96.7 to 113.6%. The proposed method has the advantages of simplicity, low cost, and accurate and was successfully applied to analyze Cd(II) in rice.

Ultra-Sensitive Determination of Cadmium in Food and Water by Flame-AAS after a New Polyvinyl Benzyl Xanthate as an Adsorbent Based Vortex Assisted Dispersive Solid-Phase Microextraction: Multivariate Optimization

“…Xue et al determined Cd in tea, water, distilled spirits, and juice by successive homogeneous liquid-liquid microextraction, and 77.0-92.3% recovery was observed [40]. Sun et al compared the recovery of Cd(II) by FAAS using UA-DLLME and the results indicated that 96.7 to 113.6% was achieved in glutinous rice, polished rice, and brown rice samples [41]. Shamsipur et al prepared the Natural DES-based ultrasound-vortex-assisted DLLME determination of trace levels of Cd ions in food and water.…”

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…A few reports are noteworthy because of the extent of the factor space that was searched. Sun et al , 58 in devising a method for the determination of Cd in rice by ultrasound-assisted DLLME and FAAS, investigated the effects of 10 ligands, four disperser solvents and three extraction solvents. In a similar procedure, ultrasound-assisted DLLME involving DESs, for the pre-concentration of Se prior to determination by HG-AAS, Altunay et al 59 investigated the possibilities of six different DESs as well as the usual parameters of pH, amount of ligand, volume of DES, sonication time, and sample amount.…”