An Optical Rotatory Detector for High-Performance Liquid Chromatography Using Polarization Modulation

Abstract

A sensitive and variable-wavelength optical rotatory (OR) detector for high-performance liquid chromatography is presented. This design is entirely different from that of conventional OR detectors consisting of a crossed polarizer pair. By placing a polarizing prism and a retardation plate into a commercial circular dichroism (CD) detector, the OR signal was obtained. The Mueller matrix approach was used to prove the principle of the OR signal appearance. Sugars and 4-androstene-3,17-dione were chosen as test compounds. The limit of detection was below 0.5 μg of injected sucrose at 260 nm, which was superior to that obtained with a conventional OR detector. For 4-androstene-3,17-dione, which is CD active, and shows a large anomalous OR dispersion curve, our detector gave a large OR signal with approximately half the intensity of the CD signal at 340 nm.

Counter-ionic Effect on the Separation of Water-soluble Compounds Applying a Hydrophilic Stationary Phase Bonded with a Zwitter-ionic Polymer

“…Operating conditions were as follows: mobile phase, 0.005 or 0.020 mol L -1 salt aqueous solution/acetonitrile; flow rate, 1.0 mL min -1 ; column temperature, 40 C; injection volume, 20 μL; detector, absorbance detector at maximum adsorption wavelength of each analyte. For the measuring of glucose, a home-made optical rotation detector, 12 which was constructed by using the optical system of a Jasco (Hachioji, Japan) CD-2095 Plus detector, was used instead of an absorbance detector.…”

Determination of Adulteration in Apple Juice by HPLC with Novel Optical Rotation Detector

“…A Gran-Taylor prism (1 cm square, Sigma Koki, Tokyo, Japan) as an analyzer was placed on the transmitted beam side with the same angle to the retarder. Other conditions were the same as in our previous study (14).…”

“…We have developed a sensitive and variable-wavelength OR detector for HPLC (14). Generally OR detectors are not as sensitive as CD detectors, but the low sensitivity stems from a property of the traditional OR detector that uses an achromatic light as a probe and is not applicable in the UV region.…”

Development of a Variable-wavelength Optical Rotation Detector in the Ultraviolet Region

“…(10) in our previous paper. 9 The OR modulation wave with an amplitude of 2J1(δ) at a frequency of f Hz is obtained in this optical system. But the CD wave at a frequency of f Hz does not appear under any values of α due to the absence of parameter f in the same term of Eq.…”

“…There is no disagreement on the point that a circular dichroism (CD) detector is more sensitive compared with an OR detector, 8 but the CD gives no signal in the regions with no absorption. To solve these problems, we have proposed a non-crossed Nichol type OR detector with a polarizing modulation system, 9 and have evaluated this system by applying it to actual samples. 10 In this optical system, a retardation plate and a polarizing prism are put on the two sides of the flow-cell in a conventional CD detector and the optic axis of the prism is rotated by 45 with respect to the optic axis of the stationary prism, thus resulting in sufficient transmitted light.…”