High performance diffuse reflectance circular dichroism spectrophotometer

A new dual-purpose transmittance circular dichroism (CD) and diffuse reflectance CD (DRCD) universal chiroptical spectrophotometer (UCS-3, J-800KCMFII) was successfully developed to have the capability of measuring DRCD spectra down to 190 nm with high efficiency, based on UCS-2: J-800KCMF. Optical components newly used in UCS-3 are the integrating sphere of optimum size and material to achieve high performance particularly in the shorter wavelength region, a baffle installed to reduce the first specular reflection signals, and a condenser lens to increase light intensity per area for small samples. As a result, UCS-3 has become a very powerful instrument to measure DRCD spectra of powdered samples in situ, with approximately 20 times sensitivity of existing UCS-2. We could show that to achieve similar quality DRCD spectra, only 50 mu g of (S)-(+)-1,1(')-binaphthyl-2,2(')-diyl hydrogen phosphate is required on UCS-3, as compared with 1.12 mg for UCS-2.