Skip to content

JASCO JASCO

  • News
  • Events
  • E-Store
  • My Account
  • Contact Us
  • Worldwide
Search
Click to view menu
MENUMENU
  • Products
    • Chromatography
      • HPLC
      • RHPLC
      • UHPLC
      • LC-MS
      • Preparative LC
      • Analytical SFC
      • Semi-Preparative SFC
      • Hybrid SFC
      • Fuel Analysis by SFC-FID
      • Preparative SFC
      • Supercritical Fluid Extraction
      • Chromatography Software
    • Molecular Spectroscopy
      • Circular Dichroism
      • High-Throughput CD
      • Vibrational CD
      • Circularly Polarized Luminescence (CPL)
      • Polarimeters
      • FTIR Spectrometers
      • FTIR Microscopy
      • FTIR Portable
      • Raman Microscopy
      • Palmtop Raman Spectrometer
      • Probe Raman
      • UV-Visible/NIR Spectrophotometers
      • UV-Visible/NIR Microscopy
      • Fluorescence Spectrophotometers
      • Film Thickness
      • Spectra Manager™ Suite
    • Refurbished
      • Refurbished HPLC Systems
      • HPLC Switching Valves
      • FTIR Accessories
  • Service
    • Service and Support Plans
    • Service Request Form
  • Applications
  • KnowledgeBase
  • Learning Center
    • Best Practice
      • Circular Dichroism Tips & Tricks for Biological Samples
      • CD Scale Calibration with ACS
      • Fluorescence Tips & Tricks
      • Raman Spectroscopy Tips & Tricks
    • Training Videos
      • ChromNAV
      • SF-NAV
      • Circular Dichroism
      • UV-Visible/NIR
      • Fluorescence
    • Training Seminars
      • Training Registration Form
    • Webinars
    • eBooks
    • Theory
      • Theory of Molecular Spectroscopy
      • Chromatography
  • About Us
    • President’s Message
    • Contact
    • History
    • Careers
  • News
  • Events
  • Worldwide
  • Shop
  • My Account
  • Contact Us

Home / Applications / Optical Rotation of Dextromethorphan Hydrobromide Measured using a Polarimeter with 365nm Mercury Lamp

  • Industry

  • Technique

Optical Rotation of Dextromethorphan Hydrobromide Measured using a Polarimeter with 365nm Mercury Lamp

By Heather Haffner

PDF IconDownload This Application

August 25, 2022

Introduction

Jasco P-2000 Digital Polarimeter Dextromethorphan Hydrobromide
P-2000 Digital Polarimeter

In accordance with the U.S. Pharmacopeia (USP),  the measurement of optical rotation must be measured at 325 nm, however there is no emission line at 325 nm available in a polarimeter using a Na or Hg lamp as the light source. Therefore, for the measurement of optical rotation of Dextromethorphan Hydrobromide, a polarimeter with halogen lamp as a light source and interference filter (325 nm) has been typically used, but as shown in Fig. 1, the optical rotatory dispersion (ORD) spectrum, has very steep slope in the short wavelength range near 325 nm, where even a very small error in the wavelength of interference filter may cause a large error in the optical rotation measurement, which can make accuracy quite difficult to achieve. On the other hand, if measurement using the Hg 365nm emission line were permitted, since no wavelength error is expected, the measurement of optical rotation can be implemented with much greater accuracy.  In this experiment, dextromethorphan hydrobromide was measured using a P-2000 polarimeter with a Hg lamp  at 365 nm, with a halogen lamp and interference filter at 325 nm and with the P-2000 polarimeter using its ORD optional attachment.

Results

Figure 1. ORD spectrum of Dextromethorphan Hydrobromide

Measurement using P-2000 Polarimeter

Optical rotation (365 nm, 20°C):+2.5655° (P-2000 with Hg lamp)
Specific rotation [α]36520:+142.53
Optical rotation (325 nm, 20°C):+4.7034° (P-2000 with halogen lamp & interference filter)
Specific rotation [α]32520:+261.30

ORD attachment

Optical rotation (365 nm, 20°C):+2.5706° (P-2000 with ORD attachment)
Specific rotation [α]36520:+142.81
Optical rotation (325 nm, 20°C):+4.8726° (P-2000 with ORD attachment)
Specific rotation [α]32520:+270.70
This document has been prepared based on information available at the time of publication and is subject to revision without notice. Although the contents are checked with the utmost care, we do not guarantee their accuracy or completeness. JASCO Corporation assumes no responsibility or liability for any loss or damage incurred as a result of the use of any information contained in this document. Copyright and other intellectual property rights in this document remain the property of JASCO Corporation. Please do not attempt to copy, modify, redistribute, or sell etc. in whole or in part without prior written permission.

Featured Products:

  • P-2000

    Mercury lamp for applications in the UV region

    P-2000 Hg

  • P-2000

    Discrete sodium 589 nm D-line

    P-2000 Na+

  • P-2000

    Tungsten halogen lamp for applications in the visible region

    P-2000 WI

  • RSC-200

    Cell Holders

About the Author

JASCO Application Note

Optical Rotation of Dextromethorphan Hydrobromide Measured using a Polarimeter with 365nm Mercury Lamp

Introduction

Jasco P-2000 Digital Polarimeter Dextromethorphan Hydrobromide
P-2000 Digital Polarimeter

In accordance with the U.S. Pharmacopeia (USP),  the measurement of optical rotation must be measured at 325 nm, however there is no emission line at 325 nm available in a polarimeter using a Na or Hg lamp as the light source. Therefore, for the measurement of optical rotation of Dextromethorphan Hydrobromide, a polarimeter with halogen lamp as a light source and interference filter (325 nm) has been typically used, but as shown in Fig. 1, the optical rotatory dispersion (ORD) spectrum, has very steep slope in the short wavelength range near 325 nm, where even a very small error in the wavelength of interference filter may cause a large error in the optical rotation measurement, which can make accuracy quite difficult to achieve. On the other hand, if measurement using the Hg 365nm emission line were permitted, since no wavelength error is expected, the measurement of optical rotation can be implemented with much greater accuracy.  In this experiment, dextromethorphan hydrobromide was measured using a P-2000 polarimeter with a Hg lamp  at 365 nm, with a halogen lamp and interference filter at 325 nm and with the P-2000 polarimeter using its ORD optional attachment.

Results

Figure 1. ORD spectrum of Dextromethorphan Hydrobromide

Measurement using P-2000 Polarimeter

Optical rotation (365 nm, 20°C):+2.5655° (P-2000 with Hg lamp)
Specific rotation [α]36520:+142.53
Optical rotation (325 nm, 20°C):+4.7034° (P-2000 with halogen lamp & interference filter)
Specific rotation [α]32520:+261.30

ORD attachment

Optical rotation (365 nm, 20°C):+2.5706° (P-2000 with ORD attachment)
Specific rotation [α]36520:+142.81
Optical rotation (325 nm, 20°C):+4.8726° (P-2000 with ORD attachment)
Specific rotation [α]32520:+270.70
This document has been prepared based on information available at the time of publication and is subject to revision without notice. Although the contents are checked with the utmost care, we do not guarantee their accuracy or completeness. JASCO Corporation assumes no responsibility or liability for any loss or damage incurred as a result of the use of any information contained in this document. Copyright and other intellectual property rights in this document remain the property of JASCO Corporation. Please do not attempt to copy, modify, redistribute, or sell etc. in whole or in part without prior written permission.
28600 Mary’s Court, Easton, MD 21601 USA • (800) 333-5272 • Fax: (410) 822-7526 • jascoinc.com/applications

Close

Designed in Tokyo. TRUSTED globally.

View our support plans

Connect with JASCO

  • Facebook
  • Twitter
  • LinkedIn
  • JASCO Sales
  • 800-333-5272

Receive the latest promotions and special offers

  • This field is for validation purposes and should be left unchanged.
  • Careers
  • Press Kit
  • JASCO Privacy Policy
  • Sitemap
  • Environmental Policy

© , JASCO. All Rights Reserved.