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This study is focused mainly on impact of irrigation water quality in cultivated soil on distribution of essentials nutrients (Al, Mg, Ca, Fe, S, Si, Na, P, and K) and relatively toxic metals (As, Ba, Cr, Cu, Ti, Sn, Mn, Ni, and Zn) using an elegant Laser induced breakdown spectroscopy (LIBS) technique. A pulsed Nd:YAG laser operating at 1064 nm in conjunction with suitable detector was applied to record soil emission spectra. The abundance of these elements were evaluated via standard calibration curve Laser Induced Breakdown Spectroscopy (CC-LIBS) and calibration free Laser Induced Breakdown Spectroscopy (CF-LIBS) approaches. Quantitative analyses were accomplished under conjecture of local thermodynamic equilibrium (L.T.E) and optically thin plasma. The average electron temperatures were estimated by Boltzmann plot method for cultivated soil samples in 7800 to 9300 K range. The electron number density was ~ 1.11 × 1017 cm − 3 to 1.60 × 1017 cm − 3. Prior to application on soil samples, the experimental setup was optimized at the following parameters: pulsed energy = 60 mJpulse-1, sample to lens distance of 9.0 cm, and the gate delay of 3.5 μs. It is noteworthy that nutritional elements content of cultivated soils were found strongly dependent upon the irrigation water quality. The cultivated soil from industrial area was found rich of toxins while the cultivated land using tube well water contains toxins in least amount. Our LIBS findings were also validated by comparing its results with contents measured using a standard inductively coupled plasma optical emission spectroscopy (ICP-OES) method and both were found in excellent agreement. The present study could be highly beneficial for agricultural applications and for farmers to produce safe food products and higher crops yield.

Laser-induced breakdown spectroscopy (LIBS) was employed to determine Cr, Ni, and Zn in Neem-based beauty soaps and Neem leaves. The measurements were accomplished by attaining the optically thin p...

Laser induced breakdown spectroscopy (LIBS) was applied for analyzing the impact of earthquake on the elemental distribution of the soil, collected from the earthquake-stricken locations near Eurasian and Indian Tectonic Plates in the Kashmir Valley. The quantitative elemental analysis was carried out using an advanced calibration-free LIBS technique, assuming the establishment of optically thin plasma under the local thermodynamic equilibrium conditions. The results exhibited that the soil has nearly random concentration distribution of metallic elements such as Al, Na, and K, nonmetallic element P, micronutrients such as Fe and Si and secondary macronutrients such as Ca, S, and Mg, in and around the radius of 9 km from the epicenter of the earthquake. It is exhibited that the concentration of carbon in particular is the highest near the epicenter and declines systematically with the outward radial distance. The quantitative analysis by LIBS was confirmed and counter verified through the inductively coupled plasma atomic emission spectroscopy (ICP–OES), and results achieved by both the techniques (LIBS and ICP–OES) are in good agreement.

Quantitative investigation of essential and trace heavy elements present in health-beneficial dry fruits (Pistachio, Almonds, Black walnut, White walnut, and Cashew) was investigated using Laser Induced Breakdown Spectroscopy. For an accurate elemental exposure using LIBS technique, the local thermo-dynamical equilibrium of the laser induced plasma was established and verified using McWhirter criterion based on the electron number density in the plasma. Earlier to engage, our LIBS detector was optimized. For quantification of elements, standard calibration curves (CC)-LIBS method was applied. Using our LIBS system, the nutritional elements such as Al, Mg, Ca, Fe, K, Zn, and Na and toxins like Pb, Cr, and Cu were detected in dry fruits. The elemental quantification of dry fruit contents were validated using standard (ICP-AES) method and the relative accuracy of our experimental setup in comparison to ICP approach was in the ranging from 0.1 to 0.3 at 2.5-% error confidence.

This study focuses on the application of laser-induced breakdown spectroscopy (LIBS) to determine lead and chromium in pristine aloe vera and aloe vera based beauty soaps using the second harmonic ...

In the current study, we applied laser induced breakdown spectroscopy (LIBS) to determine the elemental distribution of nutritional and trace heavy metals in pepper powders available in Pakistan using the standard calibration curve of laser induced breakdown spectroscopic (CC-LIBS) technique. The samples were found to contain elements such as K, Ca, Mg, Na, Fe, Zn, Al, Pb, Cu, and Cr. In addition, we also identified the atmospheric H-alpha line of hydrogen in the spectra, which was used to estimate the electron number density. To achieve a highly sensitive LIBS system to determine the trace amounts of nutritional and toxic metals in the pepper powders and to achieve the best limit of detection, the LIBS system was optimized by studying the dependency of the LIBS signal intensity on laser irradiance, variation in spacing between the focusing lens and target, as well as on the gate width. To justify the results of the LIBS study, we also determined the concentration of similar (duplicate) peppers by digesting the samples in appropriate solvents using a standard method such as inductively coupled plasma-optical emission spectrometry (ICP-OES). The minimum detection limit was obtained for trace heavy metals from the calibration curves. The results of LIBS displayed noteworthy conformity with those acquired from the ICP-OES analysis. The results of both the techniques clearly revealed that K was the most abundant element in all the peppers, followed by Ca, Mg, Na, Fe, Al, Pb, Zn, Cu, and Cr. The relative accuracy of our LIBS system for different species as compared with the ICP technique was in the range of 0.08-0.3 at 2.5% error confidence. Conclusively, the present work demonstrated the suitability of the LIBS technique due to its rapid, non-destructive, and eco-friendly approach for food security.

In this work, qualitative as well as the quantitative study of nutritional and trace toxic metals in various dry milk powders (local and branded) available in Pakistan was accomplished by calibration free-laser induced breakdown spectroscopy (CF-LIBS). To analyze the optical emission spectra, a pulsed Nd-YAG laser was utilized to produce micro-plasma on the surface of samples. The emitted light was acquired with a dedicated spectrometer for subsequent analysis and quantification of the species in the target. Ca, K, Mg, Na, P, Zn, Al, and S were identified as nutritional elements, while Cd, Cr, Cu Mn, and Ni as heavy metals. Our LIBS system was optimized by parametric dependence study. The average plasma temperatures were estimated using Boltzmann plot method for all types of milk powder between 8000 and 95,000 K. The electron number density was determined from the Stark broadened line profile of balmer hydrogen line (H-alpha) between 1.12 × 1017 cm−3 and 1.61 × 1017 cm−3. The emission lines used in CF-LIBS were characterized for the effect due to phenomenon of self-absorption but were found insignificant. Furthermore, the concentrations determined using CF-LIBS were compared to the abundance of identical (duplicate) dry milk powder samples obtained using a standard analytical tool like inductively coupled plasma-optical emission spectroscopy. Both the results were in outstanding harmony. Our study showed that LIBS is a powerful and rapid approach to quantify the chemical concentrations of food products.

A detection system based on Laser Induced Breakdown Spectroscopy (LIBS) was designed, optimized, and successfully employed for the estimation of lead (Pb) content in drilling fueled soil (DFS) collected from oil field drilling areas in Pakistan. The concentration of Pb was evaluated by the standard calibration curve method as well as by using an approach based on the integrated intensity of strongest emission of an element of interest. Remarkably, our investigation clearly demonstrated that the concentration of Pb in drilling fueled soil collected at the exact drilling site was greater than the safe permissible limits. Furthermore, the Pb concentration was observed to decline with increasing distance away from the specific drilling point. Analytical determinations were carried out under the assumptions that laser generated plasma was optically thin and in local thermodynamic equilibrium (LTE). In order to improve the sensitivity of our LIBS detection system, various parametric dependence studies were performed. To further validate the precision of our LIBS results, the concentration of Pb present in the acquired samples were also quantified via a standard analytical tool like inductively coupled plasma/optical emission spectroscopy (ICP/OES). Both results were in excellent agreement, implying remarkable reliability for the LIBS data. Furthermore, the Limit of detection (LOD) of our LIBS system for Pb was estimated to be 125.14 mg L-1.

In this work, we applied laser-induced breakdown spectroscopy (LIBS) to estimate the amount of toxic heavy metals (Pb, Cr, Ni) in five different brands of face foundation powders available in the local market using standard calibration curve (CC)-LIBS approach. These samples contain toxic elements like lead, chromium, nickel which are highly carcinogens to cause eczematous and atopic dermatitis. The strongest atomic transition lines of lead (405.7 line), chromium (425.4 nm line), and nickel (336.9 nm line) were used as spectral markers to simultaneously detect these three heavy metals in face powder samples. The LIBS experimental parameters (delay time, laser energy, and focusing lens to target spacing) were optimized to enhance the signal to noise ratio in the resulting LIBS spectra. The consequence of self-absorption on the marker peaks used in the LIBS analysis was investigated and found to be insignificant. We calibrated our LIBS system for these three heavy metals, whose levels were found above the permissible limits. The face foundation powder used every day augments up to considerable exposure of heavy metals in the human body which could cause many skin disorders. Our LIBS quantitative results were also cross-validated by analysis using a standard analytical technique known as inductively coupled plasma-optical emission spectroscopy (ICP-OES). This study is highly significant due to the excessive use of cosmetic products especially face powder that could affect the health of millions of people around the globe.

Fuller's earth, most commonly known as Multani Matti (clay) in Urdu, among its various utilizations is traditionally used in skin care cosmetics, particularly for removing blackheads and to treat oily skin. It is also used for improving skin complexion. In this paper, laser-induced breakdown spectroscopy (LIBS) was effectively employed for the quantitative investigation of various clay samples for their special uses. To get the LIBS spectra with an optimal signal-to-noise as well as for a more robust and accurate analytical investigation, different experimental parameters (laser energy, gate delay time, and the distance between target and focusing lens) were optimized before the experiments on actual samples. The analysis of emission spectra revealed the presence of many different elements, including Al, Ca, Fe, Mg, Mn, Na, K, Li, S, Si, and Zn. The electron number density and plasma temperatures were determined using the Stark broadened line profile and Boltzmann plot method, respectively. To determine the relative concentration of observed elements, we used an integrated intensity ratio method, integrated intensity of every line from all elements, and calibration free (CF)-LIBS. The prevailing condition of local thermodynamic equilibrium during the experimental executions was verified with multiple criteria. The spectral lines used in CF-LIBS were characterized for the influence from the self-absorption phenomenon, but the same was found insignificant. The findings of our LIBS system were found to agree excellently with the outcomes of the inductively coupled plasma/optical emission spectroscopy, thereby yielding a high statistical correlation factor and hence enlighten the significance of LIBS as a safe and reliable tool for elemental analysis of clay samples.

Commercially available ready to use henna paste, procured from the local market in Pakistan were tested to find the level of hazardous element, lead present in the samples, using Laser Induced Breakdown Spectroscopy (LIBS). The source of lead in the ready to use henna is from the artificial chemical additives in henna paste, added to enhance the color and also to speed up the dying of the henna tattoo in hand, feet, and body. Henna tattooing is an inevitable practice in the social events in the cultures of the Indian subcontinent and the Arabian Peninsula. The frequent reckless use of henna, particularly lavishly administering it to the children is quite dangerous, although the level of lead found in the commercially available ready to use henna samples are within the permissible safe level. For the sensitive detection and quantification of lead, various experimental and plasma parameters in the LIBS detection system were optimized and the system was calibrated. The quantitative analysis of lead, carried out in five different samples of ready to use henna, using LIBS revealed that the concentration of lead in these samples is between 5.5 ± 0.2 mg Kg−1 and 16.0 ± 0.2 mg Kg−1. Moreover, LIBS elemental analysis of natural henna leaves, cultivated in Sindh and Punjab regions of Pakistan, and also the soils taken from the locations of cultivation were carried out and a correlation in the elemental compositions between the henna leaves and the cultivated soil in the proximity were studied. The quantitative analysis of LIBS results were validated by atomic absorption spectroscopy (AAS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES).

We studied laser ablation and plasma property evolution for a nickel (Ni) doped tin (Sn) oxide nanostructures target using laser-induced breakdown spectroscopy (LIBS). The transition metal Ni doped tin oxide nanostructures were synthesized by co-precipitation and hydrothermal methodologies. The size of prepared nanoparticles was verified by X-ray diffraction and transmission electron microscopy techniques. A frequency-doubled pulsed Nd:YAG laser with a wavelength of 532 nm was used to produce ablated plasma nanostructures. Ablation of doped and undoped nanostructures revealed salient-enhanced spectral emissions compared with their bulky counterparts. The emission lines of the constituent elements of doped material were used to find plasma parameters. The plasma temperature was estimated from a Boltzmann plot, and the electron number density was determined from the Saha–Boltzmann equation. The self-absorption effect has been observed in tiny plasma of nanostructures. The affected profiles of spectral lines of Ni and Sn nanoparticles due to self-absorption in LIBS spectra were corrected by the internal reference self-absorption correction (IRSAC) methodology. After correction of emitted line intensities by IRSAC, the electron number density (END) conservation approach was applied for quantitative analysis of doped nanostructures. In the END conservation approach, quantitative analysis of samples was carried out using electron number densities. Quantitative results derived from the END conservation approach at high and low concentrations exhibited good correlation when these were compared and validated with results from a conventional calibration free approach and the standard recognized energy dispersive X-ray technique.

Laser-induced breakdown spectroscopy (LIBS) was applied as a potential tool for the determination of xenobiotic metal in monosodium glutamate (MSG). In order to achieve a high-sensitivity LIBS system required to determine trace amounts of metallic silver in MSG and to attain the best detection limit, the parameters used in our experiment (impact of focusing laser energy on the intensity of LIBS emission signals, the influence of focusing lens distance on the intensity of LIBS signals, and time responses of the plasma emissions) were optimized. The spectra of MSG were obtained in air using a suitable detector with an optical resolution of 0.06 nm, covering a spectral region from 220 to 720 nm. Along with the detection of xenobiotic silver, other elements such as Ca, Mg, S, and Na were also detected in MSG. To determine the concentration of xenobiotic silver in MSG, the calibration curve was plotted by preparing standard samples having different silver abundances in an MSG matrix. The LIBS results of each sample were cross-verified by analyzing with a standard analytical technique such as inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Both (LIBS and ICP-AES) results were in mutual agreement. The limit of detection of the LIBS setup was found to be 0.57 ppm for silver present in MSG samples.

A responsive laser induced breakdown spectroscopic system was developed and improved for utilizing it as a sensor for the classification of quartz samples on the basis of trace elements present in the acquired samples. Laser induced breakdown spectroscopy (LIBS) in conjunction with discriminant function analysis (DFA) was applied for the classification of five different types of quartz samples. The quartz plasmas were produced at ambient pressure using Nd:YAG laser at fundamental harmonic mode (1064 nm). We optimized the detection system by finding the suitable delay time of the laser excitation. This is the first study, where the developed technique (LIBS+DFA) was successfully employed to probe and confirm the elemental composition of quartz samples.

The spectroscopic analysis of high protein nigella seeds (also called Kalonji) was performed using pulsed nanosecond laser-induced breakdown spectroscopy (LIBS) at 532 nm. The emission spectrum of Kalonji recorded with an LIBS spectrometer exposed the presence of various elements like Al, B, Ba, Ca, Cr, K, P, Mg, Mn, Na, Ni, S, Si, Cu, Fe, Ti, Sn, Sr, and Zn. The plasma parameters (electron temperature and electron density) were estimated using Ca–I spectral lines and their behavior were studied against laser irradiance. The electron temperature and electron density was observed to show an increasing trend in the range of 5802–7849 K, and (1.2–3.9) × 1017 cm− 3, respectively, in the studied irradiance range of (1.2–12.6) × 109 W/cm2. Furthermore, the effect of varying laser energy on the integrated signal intensities was also studied. The quantitative analysis of the detected elements was performed via the calibration curves drawn for all the observed elements through typical samples made in the known concentration in the Kalonji matrix, and by setting the concentration of P as the calibration. The validity of our LIBS findings was verified via comparison of the results with the concentration of every element find in Kalonji using the standard analytical tool like ICP/OES. The results acquired using LIBS and ICP/OES were found in fine harmony. Moreover, limit of detection was measured for toxic metals only.

Laser-induced breakdown spectroscopy (LIBS) was used for the quantitative analysis of elements present in textile dyes at ambient pressure via the fundamental mode (1064 nm) of a Nd:YAG pulsed laser. Three samples were collected for this purpose. Spectra of textile dyes were acquired using an HR spectrometer (LIBS2000+, Ocean Optics, Inc.) having an optical resolution of 0.06 nm in the spectral range of 200 to 720 nm. Toxic metals like Cr, Cu, Fe, Ni, and Zn along with other elements like Al, Mg, Ca, and Na were revealed to exist in the samples. The %-age concentrations of the detected elements were measured by means of standard calibration curve method, intensities of every emission from every species, and calibration-free (CF) LIBS approach. Only Sample 3 was found to contain heavy metals like Cr, Cu, and Ni above the prescribed limit. The results using LIBS were found to be in good agreement when compared to outcomes of inductively coupled plasma/atomic emission spectroscopy (ICP/AES).

An optimized laser-induced breakdown spectroscopy (LIBS) system was utilized as a robust tool for the detection of high toxic lead (Pb) in often used edible colors available in local markets. Edible colors are extensively used in different food stuffs and sweet dish items. To attain a highly sensitive LIBS system for the determination of trace amounts of toxic Pb in edible colors and to achieve the best detection limit, various parametric dependence studies were performed. The quantitative determinations were accomplished under the condition of local thermodynamic equilibrium in terms of optically thin plasma. Besides toxic Pb, other elements like Ca, Mg, Fe, and Na were also detected in edible colors. To estimate the concentration of toxic lead in edible colors, calibration curves were plotted by preparing standard samples of different lead concentrations in an edible colors matrix. Results of the LIBS technique were compared with the outcomes of the same samples studied using a standard analytical technique of inductively coupled plasma-optical emission spectroscopy to confirm the contemporary LIBS setup. The color samples were found above the safe permissible level due to the mass of toxic lead. Limit of detection of the LIBS setup was found at 0.86+/-0.03 ppm for toxic lead present in edible color samples.

A spectrometer based on pulsed nanosecond laser-induced breakdown spectroscopy (LIBS) was employed for the quantitative determination of heavy and essential metals in salts from various sources available in Pakistan. Six salt samples were collected from sea salt and rock salt. Toxic metals (Cu, Cd, and Ni) and other microessentials (Fe, Ca, Co, Mg, Mn, S, and Zn) were investigated from the recorded spectra. The detection system was calibrated using a parametric dependence study. The quantitative analyses were accomplished under the assumption of local thermodynamic equilibrium and optically thin plasma. The results by the LIBS technique were in agreement with the outcomes of the same samples studied using a more standard approach like inductively coupled plasma-atomic emission spectroscopy (ICP-AES). When the concentrations of heavy and essential metals were calculated using a calibration-free LIBS method that does not need a standard salt specimen and dilution, both LIBS and ICP-AES were also in good agreement. The limit of detection of the experimental set up was determined for the observed heavy metals in the studied samples.