Sodium Urinary Test Strip

Excessive salt consumption has been associated with greater risk of hyper- tension. Therefore, monitoring of dietary sodium consumption should be prioritized. As sodium is mainly excreted through urine, 24-h urine sample can be used to estimate individual sodium intake. Thus, a simple and inex- pensive semi-quantitative urinary sodium detection test strip was developed based on the enzymatic reaction between β-galactosidase and chlorophenol red-β-d-galactopyranoside. When tested, color formation was distinguished at 0 M (chartreuse yellow), 0.05 M (sunflower), 0.1–0.15 M (mango tango), and 0.2–0.25 M (persimmon) sodium. Analysis from ImageJ showed a linear result (r2 > 0.9), low SD, and significant increase in magenta difference (p < 0.01) between 0 and 0.05–0.25 M sodium. Test strip can detect 0.03 M sodium at min- imum but did not last for >2 days in adverse storage conditions (laboratory conditions, ∼80% relative humidity, 40◦C, and direct light exposure) when stored in test strip bottles, and even shorter when exposed to the environment. The pres- ence of urinary potassium, urea, and glucose did not affect test strip performance. Test strip produced comparable results to flame photometry with <15% varia- tion when tested on overnight, random spot, and 24-h urine samples. Overall, the developed test strip can be used to enzymatically semi-quantify 0.05–0.25 M sodium.

Read more: https://iubmb.onlinelibrary.wiley.com/doi/10.1002/bab.2383?af=R