Reversed-Phase High-Performance Liquid Chromatography for the Determination of 15 Rare Earth Elements in Surface Water Sample Collected in a Mining Area from Lavras do Sul/RS, Brazil

High performance liquid chromatography coupled with post - Column derivatization methods in food analysis: Chemistries and applications in the last two decades

High performance liquid chromatography coupled with post-column derivatization is used for increasing the sensitivity and selectivity of the desirable analytes after the chromatographic separation. The transformation of the analytes can be conducted through the addition of a suitable reagent in the eluted stream or the ultraviolet irradiation of the eluted analytes, forming detectable derivatives for ultraviolet or fluorescence detectors. This review focuses on the developed methods using high performance liquid chromatography coupled with post-column derivatization for the determination of substances in food samples during the last two decades. The significance of the determination of each analyte in foods and the existing guidelines in each case are discussed. Preparation of the samples and the analytical methods are commented. For each analyte, official methods and commercially available systems and reagents are mentioned, as well.

A Prompt Study on Recent Advances in the Development Of Colorimetric and Fluorescent Chemosensors for "Nanomolar Detection" of Biologically Important Analytes

Fluorescent and colorimetric chemosensors for selective detection of various biologically important analytes have been widely applied in different areas such as biology, physiology, pharmacology, and environmental sciences. The research area based on fluorescent chemosensors has been in existence for about 150 years with the development of large number of fluorescent chemosensors for selective detection of cations as metal ions, anions, reactive species, neutral molecules and different gases etc. Despite the progress made in this field, several problems and challenges still exist. The most important part of sensing is limit of detection (LOD) which is the lowest concentration that can be measured (detected) with statistical significance by means of a given analytical procedure. Although there are so many reports available for detection of millimolar to micromolar range but the development of chemosensors for the detection of analytes in nanomolar range is still a challenging task. Therefore, in our current review we have focused the history and a general overview of the development in the research of fluorescent sensors for selective detection of various analytes at nanomolar level only. The basic principles involved in the design of chemosensors for specific analytes, binding mode, photophysical properties and various directions are also covered here. Summary of physiochemical properties, mechanistic view and type of different chemosensors has been demonstrated concisely in the tabular forms.

A Review on Conducting Polymers for Colorimetric and Fluorescent Detection of Noble Metal Ions (Ag+, Pd2+, Pt2+/4+, and Au3+)

Conducting polymers (CPs) are conductive materials composed of organic polymers. CPs have excellent properties such as easy synthesis and effortless fabrication, tunable electrical property, high environmental stability, high mechanical and optical properties. These unique properties have attracted researchers to discover a wide variety of uses, such as batteries, solar cells, sensors, supercapacitors, electrochromic devices, and biochemical applications. Although CPs have many limitations in their pristine form, hybridization with other materials overcomes these limitations. Here in this review article, we discuss different CPs based chemosensors for colorimetric and fluorimetric detection and determination of noble metal ions (Ag+, Pd2+, Pt2+/4+, and Au3+) in different environmental, agricultural, and biological samples. Further, the sensing performances of these chemosensors have been compared and discussed. We hope this article will help the readers with the future design of CPs based optical sensor (colorimetric and fluorescent) for detecting noble metal cations.

Accumulation and fractionation of rare earth elements are conserved traits in the Phytolacca genus

Rare earth elements (REEs) are now considered emerging pollutants in the environment. Phytolacca americana, an REE hyperaccumulating plant, has been proposed for the remediation of REE-contaminated soils. However, there is no REE-related information for other Phytolacca species. Here, we examined five species (P. americana, P. acinosa, P. clavigera, P. bogotensis, and P. icosandra) for their response to REEs. REE accumulation and fractionation traits both occurred on the same order of magnitude among the five species. Heavy REEs were preferentially transferred to leaves relative to light REEs. Regardless of the species, lateral root length and chlorophyll content decreased under REE exposure, and lateral roots and foliar anthocyanins increased. However, plants did not experience or only slightly experienced oxidative stress. Finally, REE exposure strongly modulated the ionome of roots and, to a lesser extent, that of leaves, with a negative correlation between REE and Mn contents. In conclusion, our study provides new data on the response of several Phytolacca species to REEs. Moreover, we highlighted that the REE accumulation trait was conserved among Phytolacca species. Thus, we provide valuable information for the phytoremediation of REE-contaminated sites since the most appropriate Phytolacca species could be selected depending on the climatic/pedological area to be remediated.