3 Advanced Methods for Detection of Contaminants
in Environmental Samples
Most of the emerging contaminants possess high water solubility due to their
chemical configuration and thus pose a potential risk for the aquatic ecosystem and
humans being through the water cycle [58]. A continuous increase in the concentration of xenobiotic and recalcitrant compounds has been observed in various
water bodies such as groundwater and surface water [1, 71]. The assessment of such
emerging pollutants in the aqueous system has turned into a key scientific task,
which demands highly sensitive analytical approaches for determination at nanograms per litre scales [81]. Different analytical techniques have been developed
among which, major techniques are comprised of gas/liquid chromatography
coupled with mass spectroscopy. The mass spectroscopy approaches have exhibited
better outcomes in the precise determination of contaminants present in the complex
composition of effluent or surface water currently, because of its sensitivity and
specificity [1]. Advanced mass spectroscopic techniques including ion trap and
triple quadrupole are applied for the determination of contaminants in the ng L
−1
scale, whereas for the structural interpretation of transformed intermediates, more
advanced techniques such as triple quadrupole, linear ion traps quadrupole, triple
quadrupole and quadrupole-linear ion trap are applied [58].
Other advanced techniques reported for the determination of emerging pollutants
present in water include microbiological assay, capillary electrophoresis and
immunoanalytical techniques. Capillary electrophoresis possesses disadvantage for
being less sensitive as compared to liquid chromatography, whereas immunoanalytical based approach relies more on antibody involved and has limitations for the
determination of various analytes simultaneously and in the case of microbiological
assays a large amount of samples are required [12]. Nowadays a significant
improvement has been achieved in the field of advanced analytical techniques. But
there is still a need for more sensitive techniques for the determination of unknown
and more complex compounds. There is a high need for the development of novel
identification techniques for the low cost and accurate determination of unknown
emerging contaminants. For the precise and accurate detection of pollutants in
environmental samples, prior treatment of the samples requires significant consideration for an analytical method. Liquid-liquid extraction has been used largely in
previous studies. However, the use of solid phase extraction has been increased in
recent times owing to its several benefits over liquid-liquid phase extraction, such as
reproducibility, applicability, and simplicity. Prior concentration of aqueous environmental samples is also considered exercise before the final determination of
lower detection limits and low quantification limits and is supporting in declining of
both the values.
A wide range of toxic pollutants when present in the environment even at low
concentrations pose a threat to human health [4, 14]. This increases the demand for the
development of a sensitive analytical technique for the determination and identification of trace and ultra-trace micropollutants in water. Recently, an increase had been
Materials in Emerging Water Pollutants Detection
259
in Environmental Samples
Most of the emerging contaminants possess high water solubility due to their
chemical configuration and thus pose a potential risk for the aquatic ecosystem and
humans being through the water cycle [58]. A continuous increase in the concentration of xenobiotic and recalcitrant compounds has been observed in various
water bodies such as groundwater and surface water [1, 71]. The assessment of such
emerging pollutants in the aqueous system has turned into a key scientific task,
which demands highly sensitive analytical approaches for determination at nanograms per litre scales [81]. Different analytical techniques have been developed
among which, major techniques are comprised of gas/liquid chromatography
coupled with mass spectroscopy. The mass spectroscopy approaches have exhibited
better outcomes in the precise determination of contaminants present in the complex
composition of effluent or surface water currently, because of its sensitivity and
specificity [1]. Advanced mass spectroscopic techniques including ion trap and
triple quadrupole are applied for the determination of contaminants in the ng L
−1
scale, whereas for the structural interpretation of transformed intermediates, more
advanced techniques such as triple quadrupole, linear ion traps quadrupole, triple
quadrupole and quadrupole-linear ion trap are applied [58].
Other advanced techniques reported for the determination of emerging pollutants
present in water include microbiological assay, capillary electrophoresis and
immunoanalytical techniques. Capillary electrophoresis possesses disadvantage for
being less sensitive as compared to liquid chromatography, whereas immunoanalytical based approach relies more on antibody involved and has limitations for the
determination of various analytes simultaneously and in the case of microbiological
assays a large amount of samples are required [12]. Nowadays a significant
improvement has been achieved in the field of advanced analytical techniques. But
there is still a need for more sensitive techniques for the determination of unknown
and more complex compounds. There is a high need for the development of novel
identification techniques for the low cost and accurate determination of unknown
emerging contaminants. For the precise and accurate detection of pollutants in
environmental samples, prior treatment of the samples requires significant consideration for an analytical method. Liquid-liquid extraction has been used largely in
previous studies. However, the use of solid phase extraction has been increased in
recent times owing to its several benefits over liquid-liquid phase extraction, such as
reproducibility, applicability, and simplicity. Prior concentration of aqueous environmental samples is also considered exercise before the final determination of
lower detection limits and low quantification limits and is supporting in declining of
both the values.
A wide range of toxic pollutants when present in the environment even at low
concentrations pose a threat to human health [4, 14]. This increases the demand for the
development of a sensitive analytical technique for the determination and identification of trace and ultra-trace micropollutants in water. Recently, an increase had been
Materials in Emerging Water Pollutants Detection
259