Microplate-based 3D-printed image box for urea determination in milk by digital image colorimetry

Area of Science:

• Analytical Chemistry
• Food Science
• Biotechnology

Background:

• Urea determination in milk is crucial for assessing milk quality and animal health.
• Existing methods for urea analysis can be time-consuming and require specialized equipment.
• There is a need for rapid, cost-effective, and high-throughput analytical techniques for milk analysis.

Purpose of the Study:

• To develop and validate a smartphone-based digital colorimetric method for rapid urea quantification in milk.
• To design a compact, cost-effective, and high-throughput system for simultaneous analysis of multiple milk samples.
• To evaluate the performance of the developed method against established analytical techniques.

Main Methods:

• A 3D-printed image box microplate system was employed for sample handling.
• Urea was quantified using its reaction with p-dimethylaminobenzaldehyde (DMAB).
• Smartphone-captured digital images were analyzed using RGB color models, with blue (B) values as the analytical signal.

Main Results:

• The developed method demonstrated a linear range for urea quantification from 50 to 400 mg L⁻¹.
• A limit of detection (LOD) of 15 mg L⁻¹ was achieved under optimized conditions.
• Results obtained using the smartphone-based method showed good agreement with spectrophotometric and mid-infrared spectroscopy analyses.

Conclusions:

• The smartphone-based digital colorimetric method provides an accessible and efficient approach for high-throughput urea analysis in milk.
• This technology has potential applications for various analytes in milk and other fields requiring colorimetric analysis.
• The developed system offers a cost-effective alternative to traditional analytical methods.