Environmental contamination by trace elements is becoming increasingly important problem worldwide. Trace metals such as cadmium, copper, lead, chromium, and mercury are major environmental pollutants that are predominantly found in areas with high anthropogenic activities. Therefore, there is a need for rapid and reliable tools to assess and monitor the concentration of heavy metal in environmental matrices. A nondestructive, cost-effective, and environmentally friendly procedure based on near-infrared reflectance spectroscopy (NIRS) and chemometric tools has been used as alternative technique for the simultaneous estimation of various heavy metal concentrations in environmental sample. The metal content is estimated by assigning the absorption features of metals associated with molecular vibrations of organic and inorganic functional groups in organic matter, silicates, carbonates, and water at 780–2500 nm in the near-infrared region. This chapter, reviewed the application of NIRS combined with chemometric tools such as multiple linear regression (MLR), principal component regression (PCR), and partial least squares (PLS) regression. The disadvantages and advantages of each chemometric tool are discussed briefly.
Part of the book: Developments in Near-Infrared Spectroscopy
Determination of emerging pollutants such as UV-filters in environmental samples is very important because they have been proven to have harmful effects on human and aquatic life. In this study, a simple, fast and inexpensive method combining solid phase extraction (SPE) and UV spectrophotometry was developed for simultaneous preconcentration and determination of benzophenone and sulisobenzone in wastewater samples. The effect of factors affecting the preconcentration of UV-filters was optimized using univariate and multivariate approach. Under optimized conditions, the limits of detection (LOD), limits of quantification (LOQ) and preconcetration factors were in the range of 0.15–0.28 and 0.50–0.93 μg L−1, 50–55, respectively. The dynamic linear range was up to 250 μg L−1 for benzophenone and sulisobenzone. In addition, the intra- and inter-day precisions were 3.1–3.3 and 4.5–5.2%, respectively. The developed method was successfully applied to determine UV filters in wastewater samples attaining satisfactory recoveries over the range of 99.3–100.7%. The concentration of the target pollutants in wastewater samples ranged from 6.83 to 85.67 μg L−1.
Part of the book: Emerging Pollutants