High‐Throughput Microwave‐Assisted Digestion and Extraction Procedures for Agricultural Materials

Abstract

Despite the advances in microwave-assisted procedures, the sample throughput still remains a critical problem that requires the development of reactor vessels, rotors, and procedures able to deal with a large number of samples simultaneously. In this work, a 36-vessel rotor was combined with diluted nitric acid solution for digestion of agricultural materials. Accurate results were obtained for aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), and zinc (Zn) in bovine liver and spinach leaves standard reference materials. The EPA-3051 method was also evaluated using this system. The procedure led to quantitative recoveries of chromium (Cr), Cu, Mn, nickel (Ni), and Zn in soil. All measurements were carried out using inductively coupled plasma-optical emission spectrometry (ICP-OES). The main advantages of the proposed procedures are the increase of sample throughput in microwaveassisted digestions or extractions and the lower dilution required before pneumatic nebulization of digests obtained by using dilute nitric acid.

Multi-throughput dynamic microwave-assisted leaching coupled with inductively coupled plasma atomic emission spectrometry for heavy metal analysis in soil

“…21,22 Despite the advantages of minimal time consumption and simplication for sample preparation, the microwave assisted leaching techniques have the drawback of relatively low throughput compared to the high-pressure MAD technique. 23 Dynamic microwave-assisted extraction (DMAE) of organic pollutants from soils coupled with other enrichment technique has been developed. 24 The DMAE can reduce the total analysis time and increase the throughput of complex solid samples with simpler operation.…”

Assessment of inorganic contaminants in golden mussel (Limnoperna fortunei) in Southern Brazil

“…Microwave-assisted wet digestion in closed vessels, in view of its high digestion efficiency, relatively low reagent consumption and reduced risks of losses and contamination, by comparison with conventional digestion procedures, has been widely employed as a sample preparation method for different matrices. 26,32 The purpose of this study was to investigate the element concentration in Limnoperna fortunei collected in the São Gonçalo Channel. This mussel can be used as a biomarker of aquatic pollution in the channel.…”