Laser-based capillary polarimeter.
A laser-based capillary polarimeter has been configured to allow for the detection of optically active molecules in capillary tubes with a characteristic inner diameter of 250 microm and a 39-nL (10(-9)) sample volume. The simple optical configuration consists of a HeNe laser, polarizing optic, fused-silica capillary, and charge-coupled device (CCD) camera in communication with a laser beam analyzer. The capillary scale polarimeter is based on the interaction between a polarized laser beam and a capillary tube, which results in a 360 degree fan of scattered light. This array of scattered light contains a set of interference fringe, which respond in a reproducible manner to changes in solute optical activity. The polarimetric utility of the instrument will be demonstrated by the analysis of two optically active solutes, R-mandelic acid and D-glucose, in addition to the nonoptically active control, glycerol. The polarimetric response of the system is quantifiable with detection limits facilitating 1.7 x 10(-3) M or 68 x 10(-12) nmol (7 psi 10(-9) g) sensitivity.
Swinney
K
K
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock 79409-1061, USA.
Hankins
J
J
Bornhop
D J
DJ
D002138:Calibration; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005947:Glucose / Q000032:analysis / Q000737:chemistry*; D007834:Lasers; D008333:Mandelic Acids / Q000032:analysis / Q000737:chemistry*; D011048:Polarography / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D013237:Stereoisomerism
D008333:Mandelic Acids; D005947:Glucose; C037938:mandelic acid