Analysis of constituents present in smokeless tobacco (Nicotiana tabacum)using spectroscopic techniques.

Laser-Induced Breakdown Spectroscopy (LIBS) is an analytical technique used to identify and quantify the elements present in any type of material present in any phase (solid, liquid, gas, and aerosol). In the present work, our objective is to find the presence of toxic and other elements in chewing tobacco (Nicotiana tabacum) using LIBS. Spectral signatures of elements like C, Fe, Si, Mg, Mn, Ca, Ti, Na, H, N, K, O, along with some toxic elements Al, Sr, Li, Cu, Sb, and Cr are observed in the LIBS spectra of these tobacco samples. The spectral intensity ratio is measured for quantitative analysis of elements present in the samples. Further, Atomic Absorption Spectroscopy is used for determining absolute concentration in these samples. A relation between the AAS result and the relative intensity of spectral lines measured in the LIBS is obtained using regression analysis. The multivariate technique, Principal Component Analysis (PCA), discriminates all the samples based on their toxicity and other constituents. Molecular study (Photoacoustic spectroscopy (PAS), UV-Visible (UV-vis), and FT-IR) of tobacco samples were performed to analyze the molecules present in the tobacco samples.

Liquid assisted pulsed laser ablation synthesized copper oxide nanoparticles (CuO-NPs) and their differential impact on rice seedlings.

Hydroponic experiments were conducted to investigate impact of laser ablated copper oxide nanoparticles (CuO-NPs) on rice seedlings. The present work demonstrates that exposure of lower concentrations (5, 10, 20, and 50 µM) of CuO-NPs enhance growth (in terms of fresh and dry weight and length), of rice seedlings. However, at higher concentrations (100, 200, and 500 µM) of CuO-NPs, growth (in terms of length, fresh weight and dry weight) decreased significantly (P < 0.05). Further, photosynthetic pigments (total chlorophyll and carotenoids) and protein contents were also found to be in accordance with the results of growth. This had occurred due to enhanced level of CuO-NPs accumulation at higher doses which also enhanced the level of oxidative stress markers such as hydrogen peroxide (H2O2) and malondialdehyde (MDA). Chlorophyll a fluorescence parameters (Fv/Fm and qP and except NPQ) and amount of some minerals (Ca, Mg, Na, and K) increased at lower concentrations of CuO-NPs. In contrast, the levels of Fv/Fm and qP were significantly (P < 0.05) reduced at higher concentration of CuO-NPs, which might be due to enhanced accumulation of Cu and oxidative stresses markers. Our results showed that lower dosages of pulsed laser ablated CuO-NPs (5, 10, 20, and 50 µM) might be beneficial for growth and development of rice seedlings.

Controlled synthesis, characterization, and application of iron oxide nanoparticles for oral delivery of insulin.

Impurity-free, controlled synthesis of iron oxide nanoparticle, in ultrapure water and chitosan, using laser ablation technique and its application for type II diabetes management through oral delivery of insulin-loaded iron oxide-chitosan nanocomposite is presented. The purity of the nanoparticle is monitored by laser-induced breakdown spectroscopy technique. The synthesized iron oxide nanoparticle was characterized by UV/Vis absorption spectroscopy, and morphological study was performed by scanning electron microscope. The intensity of absorption peak and wavelength corresponding to peak of the nanoparticle prepared in water and chitosan is dependent on the laser energy used for ablation purpose. Red shift in the absorption peak wavelength was observed by increasing laser energy. In addition to red shift, an increase in intensity of absorption peak was also seen when ablating laser energy was increased. The appearance of a weak peak around 295 nm was observed in iron oxide-chitosan nanocomposite. The spherical shape of the nanoparticle synthesized at the lower laser energy has gradually changed to triangular and irregular shaped structures as ablating laser energy was increased. The spherical nanoparticles loaded with insulin were used for oral delivery for diabetic management. The iron oxide-chitosan nanocomposite loaded with insulin has resulted in reduction in blood glucose level in mild diabetic, subdiabetic, and severely diabetic rats; more than 51 % reduction in blood glucose level, compared to the control group, has been achieved in the present work.

Study of different concentric rings inside gallstones with LIBS.

Gallstones obtained from patients from the north-east region of India (Assam) were studied using laser-induced breakdown spectroscopy (LIBS) technique. LIBS spectra of the different layers (in cross-section) of the gallstones were recorded in the spectral region 200-900 nm. Several elements, including calcium, magnesium, manganese, copper, silicon, phosphorus, iron, sodium and potassium, were detected in the gallstones. Lighter elements, including carbon, hydrogen, nitrogen and oxygen were also detected, which demonstrates the superiority of the LIBS technique over other existing analytical techniques. The LIBS technique was applied to investigate the evolution of C(2) swan bands and CN violet bands in the LIBS spectra of the gallstones in air and an argon atmosphere. The different layers (dark and light layers) of the gallstones were discriminated on the basis of the presence and intensities of the spectral lines for carbon, hydrogen, nitrogen, oxygen and copper. An attempt was also made to correlate the presence of major and minor elements in the gallstones with the common diet of the population of Assam.