Microwave‐Assisted Sample Preparation for Spectrochemistry

Abstract

Microwave‐assisted sample preparation was a major developmental step in combining the overall quality and speediness of spectrochemical analysis with the initial step of converting solid samples into representative solutions. Instrumentation and applications for organic and inorganic samples are discussed in detail after briefly addressing the fundamentals of the method. The feasibility of using diluted acid solutions and pressurized oxygen vessels for sample digestion is rationalized and clearly related to recent advances in reaction vessel materials and the interaction between matter and microwave radiation. Applications based on microwave‐induced combustion (MIC) and procedures developed for chemical speciation are also highlighted. A list of ideal attributes for microwave‐assisted sample preparation is proposed and evaluated considering the state of the art. Major needs, mainly related to the capacity of digesting large sample masses and improvements in sample throughput, are also pointed out.

Experimental Models of Characterization and Analysis of Industrial Waste

“…(Stenvall et al 2013;Dahlén & Lagerkvist 2008;Van der Sloot & Kosson 2012;Musee et al 2008;Guta et al 2013). In the literature there are presented a series of preparation methods for waste samples in order to determine the heavy metals from them, such as digestion in open systems and closed systems (Mester & Sturgeon 2003;Qi et al 2007;Nóbrega & Donati 2011;Ramanathan & Ting 2015), combustion (Flores et al 2007), ultrasonic extraction and solvent dilution (Nelson et al 2015;Mello et al 2012). The paper presents two experimental models for the characterization and analysis of industrial wastes and their application for wastes samples preparation and pretreatment in order to determine heavy metals such as Cu, Zn, Ni and Pb.…”

Development and Evaluation of a Novel Sulphur Analysis Method

“…The preparation technique should be compatible with multi-elemental analysis, safe, ecofriendly, and user friendly with a high sample throughput [5].Sample combustion is the decomposition of samples in the presence of oxygen: oxygen bomb combustion, oxygen flask combustion (OFC), and microwave-induced combustion (MIC).…”

“…Generally contamination is considered to be low, but are present in cases where the bomb is not cleaned effectively between different types of samples and if the absorbing solution contains trace elements. Only basic absorbing solutions are considered with H 2 O 2 and carbonates being highly preferred due to its absorption ability of sulphur compounds [5], [8]. The overall method is considered to be fast but an additional equilibrium period allow for extra absorption [1].…”

Strategies to improve accuracy and sensitivity in phosphorus determinations by inductively coupled plasma quadrupole mass spectrometry

“…23, No. 4, 2012 digestions require HNO 3 , 16 the difficulty of determining P by ICP-QMS becomes evident. Different He and H 2 CRI flow rates are evaluated for P determinations at m/z 31 ( 31 P + ) and 47 ( 31 P 16 O + ).…”