Sensitivity and Calibration of the FT-IR Spectroscopy on Concentration of Heavy Metal Ions in River and Borehole Water Sources

Abstract

Heavy metals in water sources can threaten human life and the environment. The analysis time, need for chemical reagents, and sample amount per analysis assist in monitoring contaminants. Application of the Fourier Transform Infrared (FT-IR) Spectroscopy for the investigation of heavy metal elements has significantly developed due to its cost effectiveness and accuracy. Use of chemometric models such as Partial Least Square (PLS) and Principle Component Regression Analysis (PCA) relate the multiple spectral intensities from numerous calibration samples to the recognized analytes. This study focused on the FT-IR calibration and quantification of heavy metals (Ag, Cd, Cu, Pb and Zn) in surveyed water sources. FT-IR measurements were compared with the atomic absorption spectrometer (AAS) measurements. Quantitative analysis methods, PCA and PLS, were used in the FT-IR calibration. The spectral analyses were done using the Attenuated Total Reflectance (ATR-FTIR) technique on three river and four borehole water sources sampled within two seasons in QwaQwa, South Africa (SA). The PLS models had good R2 values ranging from 0.95 to 1 and the PCA models ranged from 0.98 to 0.99. Significant differences were seen at 0.001 and 0.05 levels between the PLS and PCA models for detecting Cd and Pb in the water samples. The PCA models detected Ag concentrations more (˂0 mg L−1 on selected sites). Both the PLS and PCA models had lower detection only for Zn ions mostly above 45 mg L−1 deviating from the AAS measurements (<0.020 mg L−1). The FT-IR spectroscopy demonstrated good potential for heavy metal determination purposes.

Rapid Prediction of Fig Phenolic Acids and Flavonoids Using Mid-Infrared Spectroscopy Combined With Partial Least Square Regression

“…Earlier studies showed that the FTIR spectroscopy provided satisfactory results with high-throughput screening framework of numerous biomolecules in several food samples mainly fruits, vegetables, or beverages, e.g., biosynthesis of silver nanoparticles in figs ( Jacob et al, 2017 ), Sudanese honey ( Tahir et al, 2017 ), discrimination of bovine, porcine and fish gelatins ( Cebi et al, 2016 ), fatty acid changes in Caenorhabditis elegans ( Bouyanfif et al, 2019 ), mini kiwi ( Baranowska-Wójcik and Szwajgier, 2019 ), red bell pepper ( Prabakaran et al, 2017 ). Therefore, FTIR spectroscopy has emerged as a potential alternative for highly rapid metabolic fingerprinting technique, which can be applied in conjunction with an attenuated total reflection (ATR) correction procedure ( Mamera et al, 2020 ). However, FTIR provides complex spectra, which consists of many related variables (wavenumber) per sample, making its visual analysis very difficult.…”

“…Hence, the chemometric and data mining approaches are usually applied to simplify or dimensionally reduce the dataset to fewer independent parameters, with a minimal loss of total variance, thereby making human interpretation easier ( Lu et al, 2011 ). Achieving reproducible results, spectra dimensionality reduction and high fingerprinting throughput acquisition requires a rigorous use of chemometric models capable of associating the numerous spectral intensities from multiple calibration samples to identify chemical fingerprints within samples by removing potential outliers and determining the principal components capturing the high amount of total variance within the dataset ( Mamera et al, 2020 ). The most commonly used multivariate calibrations is partial least squares (PLS), which is an appropriate method for predistortion when highly collinearity is present within the dataset.…”

Formulation of Novel Composite (Activated Nanoclay/Hydrocolloid of Nostoc sphaericum) and Its Application in the Removal of Heavy Metals from Wastewater

“…This would be due to the functional groups of the clay and hydrocolloid that would be responsible for the complexation of Pb 2+ and Cd 2+ and Zn 2+ , due to the O and N binding atoms [ 15 , 79 , 80 ]. Likewise, this would be due to the synergistic effect of the functional groups -OH of Al-OH and Si-OH of the octahedral sheet in the activated clay and -NH and -OH of the hydrocolloid [ 40 , 41 , 80 , 81 , 82 ].…”

Potential Use of Biochar in Pit Latrines as a Faecal Sludge Management Strategy to Reduce Water Resource Contaminations: A Review

“…Heavy metals concentration in pit latrines is lower than reported in wastewater sludge [52]. However, heavy metal elements are one of the main persistent contaminants of pit latrine leaching or municipal wastewater [48,53]. The persistence of heavy metals in effluent is caused by their non-biodegradable and harmful nature [54].…”

“…Metals are mobilized and transported into the food web because of the leaching process from waste dumps, polluted soils, and water [55]. The most common toxic heavy metals in wastewater and sewage sludge include arsenic (As), lead (Pb), mercury (Hg), cadmium (Ca), chromium (Cr), copper (Cu), nickel (Ni), silver (Ag), and zinc (Zn) [48,53,[56][57][58][59]. There is increasing evidence linking Hg, Pb, As, and Cd toxicants to the incidence of cognitive impairments and cancers in children [60].…”