Drick DRK-WXG-4 Visual Polarimeter

Overview

The Drick DRK-WXG-4 Visual Polarimeter is a manually operated, circular-scale optical instrument designed for precise measurement of optical rotation in optically active substances. Based on the fundamental principle of polarimetry—namely, the rotation of plane-polarized light as it passes through chiral media—the DRK-WXG-4 employs a fixed sodium D-line lamp (589.3 nm) as its monochromatic light source, ensuring wavelength consistency critical for comparative and regulatory measurements. Unlike automated or digital polarimeters with temperature-controlled cells or photodetector-based angular encoding, the DRK-WXG-4 utilizes a human-read vernier scale aligned with a half-shade field observation system, enabling direct visual null-point detection. This classical design prioritizes mechanical robustness, operational transparency, and pedagogical clarity—making it especially suitable for academic laboratories, QC environments where method traceability is emphasized, and routine analysis of pharmaceutical intermediates, sugars, amino acids, and natural product extracts under standardized conditions.

Key Features

• Manual vernier-scale readout with dual circular scales (0–360° and −180° to +180°), facilitating intuitive interpretation of dextro- and levorotatory behavior
• Digital angular display integrated into the ocular assembly, providing real-time numeric confirmation of the manually adjusted reading
• High-stability sodium vapor lamp (589.3 nm) with regulated power supply, minimizing spectral drift and intensity fluctuation during extended operation
• Robust aluminum alloy optical housing with anti-vibration base plate and precision-ground glass polarizer/analyzer elements
• Standard 100 mm and 200 mm path-length sample tubes included; compatible with industry-standard 10 mm and 22 mm tube diameters
• No built-in temperature regulation—intended for use in climate-controlled laboratory environments (20–25 °C) per ASTM E1252 and USP <781> guidelines

Sample Compatibility & Compliance

The DRK-WXG-4 supports transparent, non-scattering liquid samples in standard quartz or glass sample cells. It is routinely employed for quantifying specific optical rotation [α] of sucrose solutions (per ICUMSA Method GS3/8-4), L-glutamic acid (USP Monograph), and synthetic chiral compounds in organic solvents such as ethanol, water, and chloroform. While the instrument itself does not provide electronic audit trails or user access control, its manual operation aligns with GLP-compliant workflows when paired with controlled documentation procedures (e.g., paper-based logbooks, signed calibration records, and operator qualification files). It meets the essential optical performance criteria outlined in ISO 13805:2019 (Polarimetry — General requirements) and serves as a reference-grade tool for method verification in settings where automated systems require periodic manual cross-checking.

Software & Data Management

The DRK-WXG-4 operates without embedded firmware or proprietary software. All measurement data are recorded manually by the operator, supporting full procedural transparency and eliminating risks associated with software validation overhead. Users may integrate readings into external LIMS or Excel-based QA databases using standardized templates. Though lacking USB or RS-232 output, the digital display allows for timed visual recording—facilitating compliance with FDA 21 CFR Part 11 when combined with documented operator training, controlled blanking protocols, and independent verification steps. Calibration is performed using certified quartz rotatory standards traceable to NIM (National Institute of Metrology, China) or equivalent national metrology institutes.

Applications

• Pharmaceutical quality control: Verification of enantiomeric purity in APIs per ICH Q5C and EP 2.2.7
• Food & beverage testing: Sucrose concentration determination in syrups, honey, and fruit juices per AOAC Official Method 952.07
• Academic teaching: Demonstration of chirality, Fresnel’s theory of optical activity, and Biot’s empirical law in undergraduate physical chemistry labs
• Essential oil analysis: Screening of authenticity and adulteration in citrus and mint oils via specific rotation deviation thresholds
• Chemical synthesis monitoring: Real-time tracking of asymmetric reaction progress in bench-scale catalytic hydrogenations or enzymatic resolutions

FAQ

Is the DRK-WXG-4 compliant with pharmacopeial standards such as USP <781> or EP 2.2.7?
Yes—its sodium D-line illumination, angular accuracy of ±0.05°, and mechanical stability satisfy the core instrumental requirements specified in these monographs for manual polarimetric assays.
Can the instrument be used with temperature-controlled sample cells?
No—the DRK-WXG-4 lacks integrated thermal management; however, externally thermostatted jacketed cells (e.g., from Huber or Julabo) can be mounted manually if environmental control is required.
What calibration standards are recommended?
Certified quartz control plates (e.g., +30.00° and −30.00° at 20 °C) traceable to NIM or PTB are advised for daily verification; sucrose solution standards (e.g., 10% w/v in water at 20 °C, [α] = +66.37°) serve as secondary references.
Does Drick provide installation qualification (IQ) or operational qualification (OQ) documentation?
Upon request, Drick supplies customizable IQ/OQ templates aligned with ISO/IEC 17025 and GMP Annex 15 frameworks, including test protocols, acceptance criteria, and signature fields for qualified personnel.
Is technical support available outside mainland China?
Yes—Drick maintains authorized service partners in Southeast Asia, the Middle East, and Latin America; remote diagnostics and English-language application support are provided directly from Jinan headquarters.