We investigate the presence of possible blends in the spectral region of the Li resonance line at 6708Å in solar-type metal-rich stars using high resolution and high S/N spectroscopic observations. Our analysis does not confirm the identification of a weak absorption feature at 6708.025Å with the low excitation Ti I line proposed recently by Reddy et al. (2002). Our analysis suggests that the unidentified absorption is most probably produced by a high excitation Si I line proposed by Müller et al. (1975). New analysis of the 6Li / 7Li isotopic ratio in HD 82943 was performed by taking the Si I line into account and using new VLT/UVES spectra of HD 82943 with a S/N ratio close to 1000. The presence of 6Li in the star's atmosphere is confirmed while the updated value for the isotopic ratio is f(6Li) = 0.05 ±0.02.