Prediction of chemical bioactivity and physical properties has been one of the most important applications of statistical and more recently, machine learning and artificial intelligence methods in chemical sciences. This field of research, broadly known as quantitative structure–activity relationships (QSAR) modeling, has developed many important algorithms and has found a broad range of applications in physical organic and medicinal chemistry in the past 55+ years. This Perspective summarizes recent technological advances in QSAR modeling but it also highlights the applicability of algorithms, modeling methods, and validation practices developed in QSAR to a wide range of research areas outside of traditional QSAR boundaries including synthesis planning, nanotechnology, materials science, biomaterials, and clinical informatics. As modern research methods generate rapidly increasing amounts of data, the knowledge of robust data-driven modelling methods professed within the QSAR field can become essential for scientists working both within and outside of chemical research. We hope that this contribution highlighting the generalizable components of QSAR modeling will serve to address this challenge.

QSAR without borders

/pdf/good-practices-in-libs-analysis-review-and-advices-3v4xent5r7.pdf

Good practices in LIBS analysis: Review and advices

On the utilization of principal component analysis in laser-induced breakdown spectroscopy data analysis, a review

This is the 30th annual review of the application of atomic spectrometry to the chemical analysis of environmental samples. This Update refers to papers published approximately between August 2013 and July 2014 and continues the series of Atomic Spectrometry Updates (ASUs) in environmental analysis that should be read in conjunction with other related ASUs in the series, namely: clinical and biological materials, foods and beverages, advances in atomic spectrometry and related techniques, elemental speciation,X-ray fluorescence spectrometry, and the analysis of metals, chemicals and functional materials. In the field of air analysis, highlights within this review period included: the use of 3D printing technology for the rapid prototyping of new air sampler components; single particle ICP-MS studies; use of a new triple-quadrupole ICP-MS for the analysis of radioactive species and the use of FEG-SEM and IBA for the analysis of gun-shot residues. In the field of water analysis, methods continue to be developed: for the extraction and preconcentration of elements; speciation of As, Cr, Hg and Sb forms and determination of elemental constituents in colloidal and NP fractions. Instrumental developments reported include the use of MC-ICP-MS for isotopic tracer studies and a review of XRF techniques and associated preconcentration procedures for trace element analysis. Many articles featuring the analysis of plants and soils appeared but, as usual, most focused on environmental applications rather than the advancement of atomic spectrometry. There have, however, been interesting developments, such as the almost bewildering increase in types of micro-extraction for analyte preconcentration and the resurgence of CS-AAS. Clearly LIBS is maturing rapidly, with soil analysis becoming more routine in nature. Also notable was the way the accident at the Fukishima-Daiichi nuclear power plant triggered development of analytical methods for the assessment of contamination in the surrounding area. Recent research indicates that geological applications still drives many of the instrumental and methodological advances in LA-ICP-MS. Fundamental studies continue to shed light on the processes involved and hence ways of improving the analysis of laser-produced aerosols. The preparation of NP powders for the production of matrix-matched RMs for microanalytical techniques such as LA-ICP-MS and SIMS showed great promise for addressing one of the major issues when analysing geological materials by these techniques. Steady advances in MC-ICP-MS methodology is feeding through to applications in isotope geochemistry, while new SIMS instrumentation is being directed towards probing fine growth structures in biogenic carbonates and inferring past climate conditions from their geochemistry. Feedback on this review is most welcome and the review coordinator can be contacted using the email address provided.

/pdf/atomic-spectrometry-update-a-review-of-advances-in-2r8uzbiose.pdf

Atomic spectrometry update – a review of advances in environmental analysis

Laser-induced breakdown spectroscopy (LIBS) has become an established analytical atomic spectrometry technique and is valued for its very compelling set of advantageous analytical and technical characteristics. It is a rapid, versatile, non-contact technique, which is capable of providing qualitative and quantitative analytical information for practically any sample, in a virtually non-destructive way, without any substantial sample preparation. The instrumentation is simple, robust, compact, and even enables remote analysis. This review attempts to give a critical overview of the diverse progress of the field, focusing on the results of the last five years. The advancement of LIBS instrumentation and data evaluation is discussed in detail and selected results of some prominent applications are also described.

A critical review of recent progress in analytical laser-induced breakdown spectroscopy

/pdf/artificial-neural-network-for-on-site-quantitative-analysis-3wqwh2i8j9.pdf

Artificial neural network for on-site quantitative analysis of soils using laser induced breakdown spectroscopy

/pdf/application-of-a-series-of-artificial-neural-networks-to-on-3rehxszat7.pdf

Application of a series of artificial neural networks to on-site quantitative analysis of lead into real soil samples by laser induced breakdown spectroscopy

Detection of explosives has always been an important fact for homeland security. Terahertz spectroscopy and imaging is an emerging, promising candidate in this field. We use time domain THz spectroscopy and we demonstrate that a methodology based on chemometrics is successful for discrimination of explosives and prediction of their concentration in complex samples made by mixture of products.

Qualitative and quantitative analysis of explosives by terahertz time-domain spectroscopy: Application to imaging

Solid samples prepared as pressed pellets containing controlled amounts of three products, namely D-(-) Fructose, Citric acid monohydrate and a-Lactose monohydrate, were analyzed by transmission terahertz spectroscopy. We report that chemometrics was efficiently applied to the terahertz spectra in order to retrieve both qualitative and quantitative information.

http://ieeexplore.ieee.org/iel7/6654602/6665392/06665823.pdf

J. El Haddad

Papers

Good practices in LIBS analysis: Review and advices

Artificial neural network for on-site quantitative analysis of soils using laser induced breakdown spectroscopy

Application of a series of artificial neural networks to on-site quantitative analysis of lead into real soil samples by laser induced breakdown spectroscopy

Qualitative and quantitative analysis of explosives by terahertz time-domain spectroscopy: Application to imaging

Chemometrics applied to analysis of terahertz spectra