On the feasibility of near infrared spectroscopy to detect contaminants in water using single salt solutions as model systems

Gowen, Aoife; Marini, Federico; Tsuchisaka, Yutaro; Luca, Silvia De; Bevilacqua, Marta; O’Donnell, Colm P.; Downey, Gerard; Tsenkova, Roumiana

doi:10.1016/j.talanta.2014.08.049

Cited by 47 publications

(33 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main absorbance bands showing a significant weight in the PLS regression vector (Figure 10) match very well with those found in the previously applied methods, and all belong to the ranges of WAMACS found in the first overtone of water (Tsenkova, 2009). The favorable prediction results are not surprising since it is well established that salts influence the spectrum of water and these changes can be used for prediction of salt concentration (Grant et al, 1989; Gowen et al, 2015). Because salts do not absorb the NIR light, these results and the previously mentioned studies demonstrate the feasibility of aquaphotomics water-mirror approach.…”

Section: Chemometrics- the Importance Of Consistencymentioning

confidence: 87%

“…The perturbation of the water matrix by salt and measurement of salt concentration are already available in aquaphotomics literature (Gowen et al, 2015) and even in very early near infrared spectroscopy applications (Grant et al, 1989). We have chosen this perturbation since it perfectly illustrates the aquaphotomics water-molecular and energy mirror concept in that the salts are practically transparent for NIR light.…”

Section: Aquaphotomics Methodsmentioning

confidence: 99%

“…The principal uniqueness of the aquaphotomics approach in the application of these two methods is the utilization of water absorbance bands for indirect quantification of analytes in water, which change the water matrix. The feasibility of this approach was demonstrated in a study whose objective was quantification of different types of salt in water solutions (NaCl, KCl, MgCl 2 , and AlCl 3 ), where the overall detection limit of 1,000 ppm was reported (Gowen et al, 2015). The experiment was reproduced in three independent laboratories by using 3 different spectrometer systems and in different ambient conditions.…”

Section: Chemometrics- the Importance Of Consistencymentioning

confidence: 99%

“…Since its establishment more than a decade ago, aquaphotomics has grown into a vast and multidisciplinary scientific field, encompassing many research areas (Table 1). Changes in the absorption spectrum of water are used for quantification of the solutes present in water, even when the solutes do not absorb NIR light at all (Grant et al, 1989; Tsenkova, 2009; Gowen et al, 2015). This so-called water-mirror approach enables measurements of concentrations previously impossible with NIR spectroscopy at ppm levels (Sakudo et al, 2006b; Tsenkova, 2008b; Gowen et al, 2013; Bázár et al, 2014, 2015), and even at ppb levels under certain experimental conditions (Sakudo et al, 2005, 2006b; Tsenkova et al, 2007b; Tsenkova, 2008a,b).…”

Section: Introduction To Aquaphotomicsmentioning

confidence: 99%

See 3 more Smart Citations

Essentials of Aquaphotomics and Its Chemometrics Approaches

et al. 2018

View full text Add to dashboard Cite

Aquaphotomics is a novel scientific discipline involving the study of water and aqueous systems. Using light-water interaction, it aims to extract information about the structure of water, composed of many different water molecular conformations using their absorbance bands. In aquaphotomics analysis, specific water structures (presented as water absorbance patterns) are related to their resulting functions in the aqueous systems studied, thereby building an aquaphotome—a database of water absorbance bands and patterns correlating specific water structures to their specific functions. Light-water interaction spectroscopic methods produce complex multidimensional spectral data, which require data processing and analysis to extract hidden information about the structure of water presented by its absorbance bands. The process of extracting information from water spectra in aquaphotomics requires a field–specific approach. It starts with an appropriate experimental design and execution to ensure high-quality spectral signals, followed by a multitude of spectral analysis, preprocessing and chemometrics methods to remove unwanted influences and extract water absorbance spectral pattern related to the perturbation of interest through the identification of activated water absorbance bands found among the common, consistently repeating and highly influential variables in all analytical models. The objective of this paper is to introduce the field of aquaphotomics and describe aquaphotomics multivariate analysis methodology developed during the last decade. Through a worked-out example of analysis of potassium chloride solutions supported by similar approaches from the existing aquaphotomics literature, the provided instruction should give enough information about aquaphotomics analysis i.e. to design and perform the experiment and data analysis as well as to represent water absorbance spectral pattern using various forms of aquagrams—specifically designed aquaphotomics graphs. The explained methodology is derived from analysis of near infrared spectral data of aqueous systems and will offer a useful and new tool for extracting data from informationally rich water spectra in any region. It is the hope of the authors that with this new tool at the disposal of scientists and chemometricians, pharmaceutical and biomedical spectroscopy will substantially progress beyond its state-of-the-art applications.

show abstract

Section: Chemometrics- the Importance Of Consistencymentioning

confidence: 87%

Section: Aquaphotomics Methodsmentioning

confidence: 99%

Section: Chemometrics- the Importance Of Consistencymentioning

confidence: 99%

Section: Introduction To Aquaphotomicsmentioning

confidence: 99%

See 2 more Smart Citations

Essentials of Aquaphotomics and Its Chemometrics Approaches

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In order to investigate the influence of the environmental when concentrating on the extraction of WAMACS related to salts, spectral data acquired at four different test locations (Gowen et al 2015) were used to construct the respective WASP of different salts. As salts do not absorb NIR light, accurate measurement of even low concentration of salts means that salts change the surrounding water molecular structure according to the number of the solvent molecules in the solution.…”

Section: Evaluate the Performance Of Nirs Combined With Chemometrics mentioning

confidence: 99%

Aquaphotomics: Near Infrared Spectroscopy and Water States in Biological Systems

Tsenkova

Kovács

Kubota

2015

Subcellular Biochemistry

View full text Add to dashboard Cite

Aquaphotomics is a new discipline that provides a framework for understanding changes in water molecular system presented as a water spectral pattern, to mirror the rest of the solution and to give a holistic description related to system functionality. One of its main purposes is to identify water bands as main coordinates of future absorbance patterns to be used as a system biomarker. This chapter presents the Aquaphotomics methodology and illustrates a way to identify specific water bands using temperature change and addition of solutions of different ionic strength as perturbations. Rapid and precise measurement of low concentration solutes has been given as a strong evidence of the vast information that "the water spectral pattern as molecular mirror" approach provides. Few applications using near infrared spectroscopy and multivariate analysis as main tools of Aquaphotomics have been presented.

show abstract

Detectability of concentration‐dependent factors by application of PCA. An indicator curve for the determination of important principal components and a post‐correction for transformation of principal components to factors

Németh

Rákosa

2018

Journal of Chemometrics

View full text Add to dashboard Cite

A semi empirical model of light absorption for binary liquid mixtures, which includes linear, parabolic, and periodic terms of concentration-dependent factors, has been developed and applied for investigating the revealability of the factors. Concentration-dependent near infrared spectra of ethanol-water mixtures and a two-component model were decomposed by principal component analysis. Generated from the principal component analysis results and called the mean coefficient of determination, an indicator is introduced for separating the important or systematic principal components with deterministic information (factor PCs) from stochastic principal components originating from spectral noise (error PCs). Moreover, a post-correction method is proposed to pull the concentration-dependent factor effects out of the systematic principal components. The first PC of ethanol-water NIR mixture spectra defines the contributions of clusters of both water and ethanol molecules in the solution to resultant absorbance signals. The second PC includes partial absorptions from ethanol-water dimers and ethanol-water-ethanol trimers. The third PC is assumed to reflect concentration-dependent restructuring of mixture structure. KEYWORDS empirical absorption model, ethanol-water mixture, indicator MCD, PCA post-correction, V-plot | INTRODUCTIONPerhaps, the principal component analysis (PCA) is the most often applied multivariate data analysis method. As an almost required method, it appears in the assessments of concentration-dependent spectra of various aqueous solutions, as well as in those of two or more component liquid mixtures, too. 1-12 PCA is primarily utilized for the determination of systematic principal components (PCs) including deterministic information [13][14][15][16] and for the generation of the input matrix of discriminant analysis, 17-19 respectively. Mostly due to ambiguity of PCA results and lack of knowledge of the relationships between systematic PCs and the latent factors, the only PCA itself has not been applied to mapping the concentration-dependent factor effects. Based on the general transformation between decompositions of common factor analysis and PCA, 20 the idea was raised how the PCs of PCA could be traced back to the factor effects. The PCs involve the factor effects of examined phenomenon. In the cases of concentration-dependent spectra of aqueous solution, particularly some alcohol-water mixtures, we have tried to reveal the potential factors out of the PCA decompositions.

show abstract

On the feasibility of near infrared spectroscopy to detect contaminants in water using single salt solutions as model systems

Cited by 47 publications

References 17 publications

Essentials of Aquaphotomics and Its Chemometrics Approaches

Essentials of Aquaphotomics and Its Chemometrics Approaches

Aquaphotomics: Near Infrared Spectroscopy and Water States in Biological Systems

Detectability of concentration‐dependent factors by application of PCA. An indicator curve for the determination of important principal components and a post‐correction for transformation of principal components to factors

Contact Info

Product

Resources

About