Determination of the Zinc Concentration in Human Fingernails Using Laser-Induced Breakdown Spectroscopy

Abstract

The absolute concentration of Zn in human fingernail clippings was determined ex vivo using 1064 nm laser-induced breakdown spectroscopy and confirmed by speciated isotope dilution mass spectrometry. A nail testing protocol that sampled across the nail (perpendicular to the direction of growth) was developed and validated by scanning electron microscopy energy-dispersive X-ray spectrometry. Using this protocol, a partial least squares (PLS) regression model predicted the Zn concentration in the fingernails of five people to within an average of 7 ppm. The variation in the Zn concentration with depth into the nail determined by laser-induced breakdown spectroscopy was studied and showed no systematic variation for up to 15 subsequent laser pulses in one location. The effects of nail hydration (dehydrated and over-hydrated) and nail surface roughness were investigated to explain an anomalously large scatter observed in the measurements. This scatter was attributed to the layered nature and fibrous structure of the fingernails, which resulted in non-uniform ablation as determined by scanning electron microscopy. This work demonstrates that a protocol consisting of low pulse energy (<10 mJ) 1064 nm laser pulses incident on human fingernail clippings in an Ar environment can produce quantifiable Zn emission in the laser-induced plasma and that the measured Zn intensity can be used to accurately predict the Zn concentration in human fingernails.

Feasibility Study on Discrimination of Neo-plastic and Non-Neoplastic Gastric Tissues Using Spark Discharge Assisted Laser Induced Breakdown Spectroscopy

“…Emissions of excited atoms, ions, and molecules in this plasma are recorded as a spectrum and analyzed for atomic identification of the sample. In recent years, this technique is mostly used for analysis of different tissues, including hard tissues such as hair, 11 nails [12][13][14][15][16][17][18] and teeth [19][20][21][22] and soft tissues such as blood, 23 cervical, 24 liver 25 and colorectal tissues. 26 What sets this method apart from other conventional methods is the convenience of sample preparation, higher speed of performance and no direct connection with samples especially contaminant materials.…”

Examining the effectiveness of consuming flour made from agronomically biofortified wheat (Zincol-2016/NR-421) for improving Zn status in women in a low-resource setting in Pakistan: study protocol for a randomised, double-blind, controlled cross-over trial (BiZiFED)

“…Nail samples will be collected two more times at approximately 7 months (average time taken for a nail to grow from formation in the nail bed to the tip of the finger) from the start of phase 1 and phase 2. The Zn concentration of hair and nail samples will be determined using laser-induced breakdown spectroscopy 23 at NeurobioTex (Galveston, Texas, USA).…”

Laser-induced breakdown spectroscopy (LIBS): a novel technology for identifying microbes causing infectious diseases

“…LIBS is a superb technology to investigate biological specimens listed above and has also proven its capability in forensic science (Miziolek et al 2006;Cremers and Radziemski, 2006;Pasquini et al 2007;Singh and Thakur, 2007;Gondal et al, 2016d, Almessiere et al, 2018. The most recent biomedical LIBS applications have been condensed in Table 1 (Sinescu et al 2008;Negrutiu et al 2008;Hamzaoui et al 2011;Singh et al 2008Singh et al , 2009aPathak et al 2011;Jaswal et al, 2016a, b;Anzano and Lasheras 2009;Yueh et al 2009;El-Hussein et al 2010;Wu et al 2008;Martin et al 2003Martin et al , 2005Melikechi et al 2008;Lee et al 2017;Samek et al 1999;Riberdy et al 2017). Figure 2 shows different LIBS applications to analyze different kinds of bacterial samples, plant samples, animal and human tissues, and skin samples to map of metal elements in tissues and to analyze bio minerals.…”

“…Martin et al 2003 Analysis of blood Blood samples O, H, C, N, Fe, Mg, Ca, K, and Na Qualitative analysis of blood and other liquid organic compounds Melikechi et al 2008 Analysis of biological specimens Salt and soil • Ca, Mg, Na, K, Al, Si, Sr, Ti, Zn, Fe, S, C, H, N, O, C, and N • Cl, S, Mg, O Analysis of common edible salts, soils, and heterogeneous biological samples Accurate analysis of S in edible salts Singh 2009b; Martin et al 2005; Lee et al 2017 Laser ablation for mineral analysis Skin, finger nail and hair • Mineral elements: B, Ca, Cr, Cu, Fe, Si, Zn, and Toxic elements: Al, Cd, Pb, and Hg • C, Ca, Mg, Na Zn, and CN in human fingernail clippings Combined application of LIBS and LIFS to the analysis of important minerals and toxic elements within the different parts of the body including specimens of skin tissue, finger nails and teeth. Absolute concentration of Zn in human fingernail using LIBSSamek et al 1999;Riberdy et al 2017 chemicals, antibodies, or biomolecular markers. Coupled with chemometrics, and neural networking (NN), LIBS investigation provides promising, real-time, and highly sensitive pointof-care diagnosis for important applications in biomedical area of research.…”