LIBS, analytical method Applications

Ferreira et al evaluated the use of the traditional linear fit and MLP-ANN models for LIBS calibration. Their aim was to obtain a quantitative multi-elemental method for pollution measurement in soil under sewage sludge application. Two sets of samples, both composed of two kinds of soil, were used for calibration and validation. The target analyte concentrations were determined using a reference analytical method based on ICP-OES. The values determined by LIBS-MLP-ANN showed low prediction errors, good correlations with the concentrations determined by ICP-OES, high accuracy and precision, low limits of detection and best potential to quantify different types of soils. 

Additives can add problems to recycling of plastics, but they can also be one of the means of identification, which might simplify the process. While analytical methods such as NIR and XRF are useful in recycling of domestic waste, LIBS finds application in case of thermoplasts (ABS, PP, PPO)... 

It sounds very pessimistic but LIBS has been shown to be capable of performing quantitative analysis at a level considered adequate for the specific analytical task investigated. Therefore, the problem is not that LIBS cannot perform quantitative analysis, but rather how to make LIBS become as accurate and reliable as the other spectroscopic methods. It will be demonstrated, that in many industrial online applications LIBS is capable to give the quantitative analytical data which are accurate enough for process control tasks (Gaft et al. 2014a). 

Nevertheless, strong limitations are also typical for LIBS as an analytical technique. The major drawback of LIBS in industrial quantitative applications is related to the stability of the spectroscopic plasma signals, which undergo considerable fluctuations that originate from the very nature of the method. The following factors are the mostly important in real fife scenarios. 

At present the real strength of LA lies in the measurement of distribution patterns of minor and trace elements in solid samples with high spatial resolution. Homogeneity testing is an application of LA-ICP-MS. There is an increasing demand for the development and validation of accurate and robust analytical technologies for the determination of the chemical characteristics of polymeric products in support of industrial needs, EC regulations (e.g. Directive on toy safety) or research. Needs are particularly acute for techniques able to determine trace element contents in solids with a minimum sample preparation. For this purpose, laser ablation-based methods, such as LA-ICP-AES/MS and laser-induced plasma atomic emission spectrometry (LIP-AES, LA-AES or LIBS) have already... 

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