title: Study of different concentric rings inside gallstones with LIBS.
abstract: 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.
authors.affiliation: Department of Physics, University of Allahabad, Allahabad, 211 002, India.
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Pathak
authors.forename: Vivek Kumar
authors.initials: VK
authors.lastname: Singh
authors.forename: Nilesh Kumar
authors.initials: NK
authors.lastname: Rai
authors.forename: Awadhesh Kumar
authors.initials: AK
authors.lastname: Rai
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Rai
authors.forename: Pramod Kumar
authors.initials: PK
authors.lastname: Rai
authors.forename: Suman
authors.initials: S
authors.lastname: Rai
authors.forename: G D
authors.initials: GD
authors.lastname: Baruah
mesh_terms: D042882:Gallstones / Q000737:chemistry / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007194:India; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods; D007834:Lasers; D013054:Spectrophotometry, Atomic / Q000295:instrumentation* / Q000379:methods