Rapid simultaneous analysis of 1-naphthol and 2-naphthol in water samples by derivative variable-offset synchronous fluorescence spectroscopy

Derivative variable-offset synchronous fluorescence spectroscopy is developed to improve the spectral resolution and the selectivity of fluorescence measurements. 1-naphthol and 2-naphthol are employed to evaluate the proposed coupled technique and the various spectral comparisons are conducted. Second derivative variable-offset synchronous scanning permits the rapid simultaneous identification and quantitative determination of 1-naphthol and 2-naphthol in a mixture from a single spectrum. 6.7–2000 ng/ml 1-naphthol and 3.6–500 ng/ml 2-naphthol can be quantified with 1-naphthol and 2-naphthol ratios of 40: 1–1: 10. The determination of 1-naphthol and 2-naphthol in various spiked water samples gave a mean recovery of 100.7% with a relative standard deviation of 2.8% for 1-naphthol and mean recovery of 99.7% with a relative standard deviation (RSD of 2.6% for 2-naphthol, respectively.