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Calcification of senile cataractous lens determined by Fourier transform infrared (FTIR) and Raman microspectroscopies
Author(s) -
CHEN K.H.,
CHENG W.T.,
LI M.J.,
YANG D.M.,
LIN S.Y.
Publication year - 2005
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.2005.01491.x
Subject(s) - raman spectroscopy , fourier transform infrared spectroscopy , carbonate , chemistry , infrared , calcification , infrared spectroscopy , phosphate , analytical chemistry (journal) , mineralogy , optics , biochemistry , pathology , chromatography , medicine , physics , organic chemistry
Summary A calcified plaque on the surface of a senile cataractous lens (CL) isolated from a 79‐year‐old male patient was identified and its chemical composition quantified using Fourier transform infrared (FTIR) and confocal Raman microspectroscopies. The noncalcified area of the same CL and hydroxyapatite (HA) were selected as a control. Several unique absorption bands, at 960, 1034 and 1090 cm −1 assigned to the ν 1 and ν 3 stretching modes of phosphate and at 875 cm −1 attributed to carbonate, were clearly displayed in the infrared (IR) spectra of calcified plaque and HA. A peak at 961 cm −1 due to the ν 1 stretching mode of phosphate was also evidenced in the Raman spectra of calcified plaque and HA. The calcified plaque formed within the lens protein was found to mainly consist of a mature HA, in which type‐A carbonate apatites (11.4%), type‐B carbonate apatites (55.6%) and liable surface carbonate ions (33.0%) were presented. A higher content of the liable carbonate implies that the calcification or mineralization in this calcified lens was incomplete and still in progress. Moreover, calcification seems not to influence the secondary structure of lens protein because both IR and Raman spectra for the lens protein in the noncalcified area and calcified plaque were similar. The result suggests that both microscopic FTIR and Raman spectroscopies were easy to perform and capable of determination of the chemical composition of a calcified CL.