RESONANCE RAYLEIGH LIGHT-SCATTERING OF THIAMINE HYDROCHLORIDE–NUCLEIC ACIDS–CETYL TRIMETHYL AMMONIUM BROMIDE SYSTEMS AND THEIR ANALYTICAL APPLICATION

Abstract

ABSTRACT Resonance Rayleigh light-scattering (RRLS) of Thiamine Hydrochloride (TH)–nucleic acids–cetyl trimethyl ammonium bromide system and its analytical application was studied by using a common spectrofluorimeter, by which nucleic acids at nanogram level can be determined. TH–CTMAB reacts rapidly with nucleic acids at room temperature and the intensity of the weak common Rayleigh light scattering (RLS) of TH–CTMAB is enhanced remarkably by nucleic acids. The effective factors were studied and the optimum conditions were obtained. In TH–nucleic acids–CTMAB system, the formation of an ion association complex of TH–nucleic acids–CTMAB is considered as the reason of the enhancement of RRLS. It was also proved that the RRLS and RLS appeared in the same light scattering process. Linear relationships were found between the enhanced RRLS intensity at 406 nm and nucleic acids concentration in the range 8.0 × 10−9–1.0 × 10−5 g/mL for fish sperm DNA (fsDNA), 2.0 × 10−8–1.0 × 10−5 g/mL for calf thymus DNA (ctDNA), 1.0 × 10−8–1.0 × 10−5 g/mL for yeast RNA (yRNA). The detection limits are 2.6, 11.0, 6.3, ng/mL for fsDNA, ctDNA and yRNA, respectively. Three synthetic samples were determined with satisfaction.