Using UV-1900i Plus to Evaluate Raw Materials for Chemical Products Based on the Hazen Color Scale

Importance of the Topic

Color evaluation of liquid raw materials such as glycerin and acetylacetone is critical for quality control in chemical industries. The Hazen scale (platinum-cobalt scale) provides a standardized, objective measure of color, reducing variability inherent to visual assessment.

Objectives and Study Overview

This study demonstrates the application of the UV-1900i Plus spectrophotometer, coupled with LabSolutions UV-Vis Color software, to quantify colors of liquid raw materials according to ISO 6271:2015 and JIS K0071-1:2017 standards. Glycerin and acetylacetone samples were evaluated against Hazen unit criteria defined in JIS K3351:2009 and JIS K8027:2020.

Methodology and Instrumentation

Measurements were performed using a UV-1900i Plus UV-Vis spectrophotometer equipped with a 50 mm optical path long-path rectangular cell holder. Pure water served as the baseline control for compensation. The transmittance spectra of samples were recorded from 380 to 780 nm with a 1 nm slit width and a fast scanning speed. Hazen unit values were derived from a built-in calibration curve based on 24 platinum-cobalt standard solutions, created following ISO and JIS protocols.

Main Results and Discussion

Transmittance spectra showed:

• Glycerin exhibited uniformly high transmittance across the visible range, indicating near-colorless appearance.
• Acetylacetone displayed reduced transmittance below 500 nm, reflecting a slight yellow tint from polymerization.

Calculated Hazen unit values were 1.65 for glycerin and 16.98 for acetylacetone. Both samples met their respective pass criteria (≤ 20 Hazen for glycerin and ≤ 100 Hazen for acetylacetone). The results highlight the sensitivity of Hazen units in detecting minor chromatic differences.

Benefits and Practical Applications

• Rapid, reproducible quantification of liquid color without manual preparation of multiple standards.
• Compliance with international standards, ensuring consistent quality control.
• Enhanced detection of subtle color changes indicative of material degradation or impurity.

Future Trends and Potential Applications

The integration of automated spectroscopic color analysis with quality management systems and AI-driven data analytics is expected to expand. Adaptation of Hazen scale evaluation to additional industries, such as pharmaceuticals, food and beverages, and environmental monitoring, will enhance process control.

Conclusion

The UV-1900i Plus spectrophotometer paired with LabSolutions UV-Vis Color software offers a reliable, user-friendly solution for Hazen scale-based color assessment of liquid raw materials. This approach streamlines quality control, delivers precise color metrics, and supports compliance with ISO and JIS standards.

References

1. ISO 6271:2015 Clear liquids — Estimation of color by the platinum-cobalt color scale.
2. JIS K0071-1:2017 Test methods for color of chemical products — Part 1: Estimation of color in Hazen units.
3. JIS K3351:2009 Glycerines for industrial use.
4. JIS K8027:2020 Acetylacetone (Reagent).
5. ASTM D1209-05(2019) Standard Test Method for Color of Clear Liquids (Platinum-Cobalt Scale).