Development of semi-quantitative urinary sodium test strip.

Area of Science:

• Biochemistry
• Analytical Chemistry
• Public Health

Background:

• Excessive salt consumption is a significant risk factor for hypertension.
• Monitoring dietary sodium intake is crucial for public health.
• Urinary sodium excretion is a reliable indicator of individual sodium consumption.

Purpose of the Study:

• To develop a simple, inexpensive, and semi-quantitative test strip for urinary sodium detection.
• To assess the performance and reliability of the developed test strip.

Main Methods:

• Development of a test strip based on an enzymatic reaction (β-galactosidase and chlorophenol red-β-d-galactopyranoside).
• Colorimetric analysis of urine samples with varying sodium concentrations (0-0.25 M).
• Validation using ImageJ analysis, comparison with flame photometry, and testing on different urine sample types.

Main Results:

• The test strip demonstrated a linear response (r² > 0.9) with significant color changes correlating to sodium concentrations from 0.05 M to 0.25 M.
• The strip has a minimum detection limit of 0.03 M sodium and showed less than 15% variation compared to flame photometry.
• Urinary potassium, urea, and glucose did not interfere with test strip performance, but stability was limited under adverse storage conditions.

Conclusions:

• The developed enzymatic test strip offers a viable method for semi-quantitative urinary sodium measurement.
• This tool can aid in monitoring dietary sodium intake and assessing hypertension risk.
• Further improvements in strip stability are needed for widespread practical application.