Plastic identification based on molecular and elemental information from laser induced breakdown spectra: a comparison of plasma conditions in view of efficient sorting

Abstract

International audienceThis work is dedicated to a comparison of plasma conditions for the accurate determination of some elements: Br, Cl, Ca, P and Sb, in polymers. The comparison of the plasma conditions to sort plastics according to CN, C2 and element signals was also investigated. The comparison of a helium atmosphere and an air atmosphere led to improved results using helium as a buffer gas. The improvement is obtained in two areas, it increased the detection of halogens (Br, Cl) usually employed as flame retardants. It was also found to significantly improve the discrimination based on simple calculations of C2/He and CN/He ratios. Best conditions were based on a laser emitting at 266 nm, with a low 6 mJ energy focalized on a 50 μm spot and the helium buffer gas. A plot of C2/He against CN/He was efficient to identify the four groups of plastics employed in this study: polystyrene, polypropylene, acrylonitryle-butadiene-styrene and acrylonitryle-butadiene-styrene/polycarbonate

Comparison of ICP OES and LIBS Analysis of Medicinal Herbs Rich in Flavonoids from Eastern Europe

“…9 The LIBS technique was also successfully applied in the elemental analysis of the Chinese medicinal herb Blumea balsamifera DC in order to detect similarities and variations in elemental composition based on C, Ca and Mg concentrations in samples originating from Hainan and Guizhou provinces. 10 LIBS has been applied in the study of several other materials including polymers, 11 electronic waste, 12-14 soils, 15 cosmetics, 16 and foods, 17 all of which have confirmed its high utility in fast qualitative and quantitative analysis of diverse elements. 18,19 Concentration levels of essential elements, both macroand microelements, in medicinal herbs can represent a different range of concentrations, and are dependent on many factors: the morphological part of the plant in question, origin from different botanical species and the impact of the environment in which plant was growing before harvest (soil, precipitate or dry season, year of Vol.…”

Classification of plastic materials by imaging laser-induced ablation plumes

“…Indeed, as an eminent elemental analysis technique, LIBS has been also demonstrated to be suitable to reveal molecular structure of organic materials [13][14][15]. The combination of elemental and molecular emissions, especially those of C 2 and CN radicals, offers an ensemble of spectral features to characterize plastics and organic materials in general [16][17][18][19][20][21][22]. More recently a variant of LIBS technique has been introduced and validated to correlate the molecular structure of a polymer to the distribution and evolution of the populations of molecular species, C 2 and CN, in the ablation plume [23].…”

Atomic spectrometry update. Review of advances in the analysis of metals, chemicals and functional materials

“…The authors described how most safeguards methods measure the ratios of major isotopes such as 235 U/ 238 U or 240 Pu/ 239 Pu but that work was in progress to also include some of the minor isotope ratios. Using 238 Mention was also made of the inter-laboratory comparisons REIMEP-17 and NUSIMEP-8 for measurements of U and Pu amount content and isotopic abundances in ssile material and environmental samples. Two papers from the Argonne facility have discussed the re-certication or analysis of a certied reference material.…”

“…Several papers have used LIBS to identify plastics. [236][237][238] The paper by Barbier et al 238 studied the effects of plasma conditions on the determination of Br, Ca, Cl, P and Sb in polymers, but also studied the determination of CN and C 2 in an attempt to identify plastics to facilitate their sorting. A laser emitting at 266 nm and with a 6 mJ energy focussed on a 50 mm spot was used.…”