Plasma Spectroscopy of Various Types of Gypsum: An Ideal Terrestrial Analogue

The first detection of gypsum (CaSO4·2H2O) by the Mars Science Laboratory (MSL) rover Curiosity in the Gale Crater, Mars created a profound impact on planetary science and exploration. The unique capability of plasma spectroscopy, which involves in situ elemental analysis in extraterrestrial environments, suggests the presence of water in the red planet based on phase characterization and provides a clue to Martian paleoclimate. The key to gypsum as an ideal paleoclimate proxy lies in its textural variants and terrestrial gypsum samples from varied locations and textural types have been analyzed with laser-induced breakdown spectroscopy (LIBS) in this study. Petrographic, sub-microscopic, and powder X-ray diffraction characterizations confirm the presence of gypsum (hydrated calcium sulphate; CaSO4·2H2O), bassanite (semi-hydrated calcium sulphate; CaSO4·½H2O), and anhydrite (anhydrous calcium sulphate; CaSO4), along with accessory phases (quartz and jarosite). The principal component analysis of LIBS spectra from texturally varied gypsums can be differentiated from one another due to the chemical variability in their elemental concentrations. The concentration of gypsum is determined from the partial least-square regressions model. The rapid characterization of gypsum samples with LIBS is expected to work well in extraterrestrial environments

Gallstone Magnesium Distributions from Optical Emission Spectroscopy

This work reports measurements of calcified gallstone elemental compositions using laser-induced optical emission spectroscopy. The experimental results support the importance of the magnesium concentration in gallstone growth. Granular stones reveal an increased magnesium concentration at the periphery of the granules, suggesting the inhibition of further growth. Non-granular gallstones reveal lower overall magnesium concentrations, but with higher values near the center

Calibration Curve with Improved Limit of Detection for Cadmium in Soil: An Approach to Minimize the Matrix Effect in Laser-Induced Breakdown Spectroscopic Analysis

The present article describes a working or combined calibration curve in laser-induced breakdown spectroscopic analysis, which is the cumulative result of the calibration curves obtained from neutral and singly ionized atomic emission spectral lines. This working calibration curve reduces the effect of change in matrix between different zone soils and certified soil samples because it includes both the species' (neutral and singly ionized) concentration of the element of interest. The limit of detection using a working calibration curve is found better as compared to its constituent calibration curves (i.e., individual calibration curves). The quantitative results obtained using the working calibration curve is in better agreement with the result of inductively coupled plasma-atomic emission spectroscopy as compared to the result obtained using its constituent calibration curves

Rapid Analysis of Chemical Composition and Physical Properties of Gemstones Using LIBS and Chemometric Technique

Laser-induced breakdown spectroscopy (LIBS), accompanied by chemometric data analysis, is used to identify and classify gemstones of various hardness. The study involves several gemstones: amethyst, aquamarine beryl, bloodstone citrine, diopside, and enstatite. Their hardness is determined through a correlation utilizing the spectral intensity ratio of the ionic to atomic spectral lines of an identified element in the LIB spectrum. The result of the relative hardness obtained from the LIBS analysis is in good agreement with the hardness measured from Mohs’s scale of hardness, a popular qualitative method to determine hardness. In this work, a linear relationship has been established between the Mohs’s hardness and the plasma excitation temperature. Thus, the hardness of the gemstones can be determined with the help of plasma excitation temperature. Moreover, the analysis of trace elements in LIB spectral data reveals that a particular element is responsible for the colors of gemstones. Therefore, the relative concentration of constituents is calculated for all gemstones and compared. Principal component analysis (PCA) is successfully applied to all gemstone spectra for rapid classification and discrimination based on their variable elemental concentrations and respective hardness

Elemental Laser-Plasma Analysis of Pointed Gourd Leaves for Diabetes Management

This interdisciplinary work communicates the identification and quantification of elements responsible for the bioactive potency of leaves from pointed gourd, trichosanthes dioica, using laser-induced breakdown spectroscopy (LIBS). Calibration-free LIBS determines the presence of various trace and major elements, their concentrations, and ratios in which they are present in the leaves. The presence of specific elemental ratios of magnesium/sodium and magnesium/potassium could be promising for managing diabetes mellitus. Variable doses of aqueous extract from trichosanthes dioica leaves are administered for determination of the most effective one. Based on encouraging results, the extract could be harvested to serve as anti-diabetic medication for diabetes and associated symptoms

Novel resistance source and differentials to chilli anthracnose

Not AvailablePre- and post-harvest anthracnose fruit rot is a main disease of chilli (Capsicum spp.). Among Colletotrichum species causing anthracnose, C. capsici is the most common in India. A total of 41 Capsicum genotypes were screened for anthracnose resistance under field conditions. Bhut Jolokia, PBC-380 and IC-383072 were found symptomless and some marginally cultivated lines and other crosses were observed to be resistant. In vitro inoculation of the selected set of genotypes with C. capsici revealed that 9 days after inoculation was appropriate to record observations on disease resistance. Screening the 41 genotypes for resistance to anthracnose under in vitro conditions revealed four symptomless and 11 highly resistant lines. Comparing field and in vitro evaluations, nine lines (BS-35, BS-20, BS- 28, Punjab Lal, Bhut Jolokia, Taiwan-2, IC-383072, Pant C- 1 and Lankamura Collection) showed consistent resistance in field as well as in vitro to the disease. The study on differential reactions on fruits of 16 genotypes inoculated by the two C. capsici isolates (Ccf-Varanasi and Ccc2- Raichur) clearly showed that these isolates are two different pathotypes. A detailed analysis on prevalent strains in the target region would be needed to initiate resistance breeding. Nevertheless, newly identified resistant sources offer better choices for the ongoing anthracnose resistance breeding program.Not Availabl