Direct multi-element analysis of plastic materials via solid sampling electrothermal vaporization inductively coupled plasma optical emission spectroscopy

Abstract

In this work the determination of Cd, Cu, Cr, Fe and Sb as organic and inorganic additives in in-house plastic materials (ABS, LDPE) using electrothermal vaporization combined with inductively coupled plasma optical emission spectroscopy is described. The influence of CCl 2 F 2 as gaseous halogenation modifier was investigated. Especially for the carbide forming elements the sensitivity was improved and the memory effects were significantly reduced. Calibration was performed by external calibration and standard addition with aqueous standard solutions added directly into the sample boats. Absolute limits of detection (3s-criterion) range between 0.1 ng (Cd) and 9 ng (Fe) which corresponds to relative values of 0.1 mg kg À1 and 1.6 mg kg À1 , respectively, taking 5 mg as typical sample mass. The detection limits are sufficient to monitor the element contents of plastic materials according to European directives such as European directive on the safety of toys. The developed ETV-ICP-OES method allows a fast analysis with a high sample throughput (3 minutes per analysis), low sample consumption and good trueness and precision for the analyzed elements. Sample preparation is reduced to ashing the samples in a muffle furnace. Furthermore, measurements are possible regardless of the chemical form in the additives. For verification the results obtained with the developed method were compared with measurement results of independent methods ICP-MS/OES after digestion. In addition Cd, Cr and Pb were determined in a solid plastic reference material BAM-H010 to confirm the applicability and accuracy of the method.

Traditional Calibration Methods in Atomic Spectrometry and New Calibration Strategies for Inductively Coupled Plasma Mass Spectrometry

“…Isotope dilution and SA were then successfully used for Cr, Cd, Hg, and Pb quantification (additional examples of the use of SA will be presented in its specific section later on the text). Borno et al ( 2015 ) used EC for elemental determination in low-density polyethylene by ETV-ICP OES. However, for quantification of the analytes in acrylonitrile butadiene styrene copolymer, the ETV heating program was not efficient at decomposing the organic matrix, which compromised the method's accuracy.…”

Improvements in the direct analysis of advanced materials using ICP-based measurement techniques

“…50 Also slight variations in matrix (i.e., different types of polymers) can require the one or the other calibration approach. 51 This highly depends on the sample matrix and the analytes, and it is therefore oen useful to check whether purely aqueous standards can be used, since this type of calibration is the most straight-forward one.…”

“…12,59 In case of metallic samples, not only trace impurities were analyzed, 11,60 but also chlorine, 47 as well as the isotopic composition of the matrix metal tungsten. 44 Synthetic organic materials such as polymers and pharmaceutical components were analyzed for the presence of trace elements 42,51,61 as well as for bromine. 62 All of the mentioned sample types have in common that they are difficult to dissolve, hence the choice of ETV.…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and functional materials

“…A method has been described for solid sampling of plastics prior to analysis by ETV-ICP-OES. 308 Thus Cd, Cr, Cu, Fe and Sb were determined in different types of plastic using dichlorodi-uoromethane as a gaseous halogenation modier. The presence of this modier improved sensitivity and decreased memory effects signicantly.…”