LIBS for the detection of lead in ready to use henna paste and nutrients in fresh henna leaves and cultivated soils.

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 ±â€¯0.2 mg Kg-1 and 16.0 ±â€¯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).

Detection of carcinogenic chromium in synthetic hair dyes using laser induced breakdown spectroscopy.

A laser induced breakdown spectroscopic (LIBS) system, consisting of a pulsed 266 nm laser radiation, in conjunction with a high-resolution spectrograph, a gated intensified charge coupled device camera, and a built-in delay generator were used to develop a sensitive detector to quantify the concentration of toxic substances such as chromium in synthetic hair dyes available on the local market. The strong atomic transition line of chromium (Cr I) at 427.5 nm wavelength was used as a fingerprint wavelength to calibrate the detection system and also to quantify the levels of chromium in the hair dye samples. The limit of detection achieved by our LIBS detection system for chromium was 1.2 ppm, which enabled us to detect chromium concentration in the range of 5-11 ppm in the commercial hair dyes available on the local market. The concentrations of chromium in the hair dyes measured using our system were validated using a standard analytical technique such as inductively coupled plasma mass spectrometry (ICPMS), and acceptable agreement (nearly 8%) was found between the results obtained by the two methods (LIBS and ICPMS). This study is highly significant for human health, specifically for people using synthetic hair dyes for changing the color of their hair.