Unusually Elevated Triglycerides Due to Pure Water Contamination in Biochemical Analysis

Accurate measurement of serum triglycerides (TG) is essential for clinical diagnosis and treatment. Unexpectedly elevated TG levels in laboratory results may indicate analytical errors or contamination.

We report a case involving an unusual elevation of serum TG levels. Suspecting potential analytical interference, we first investigated issues related to quality control materials and reagents. To determine whether the pure water was the source of contamination, we performed manual TG testing. Five serum samples from the previous day, with TG concentrations of 0.72, 1.96, 2.93, 6.45, and 15.95 mmol/L, were selected for verification. A TG colorimetric strip was developed based on the final color of the enzymatic reaction system and used to compare pure water samples from the previous and current days.

Quality control materials and reagents were ruled out as potential sources of interference for the unusually elevated TG levels. The TG reaction system for the current day's pure water produced a dark purple color, indicating a TG concentration theoretically exceeding 15.95 mmol/L. In contrast, the reaction system for the previous day's pure water showed a color comparable to the saline control. These findings confirmed the presence of TG contamination in the current day's pure water, which was ultimately traced to the recent replacement of the reverse osmosis membrane in the water purification system.

The manual TG detection method developed in this case offers a rapid and practical solution for laboratories with high automation to identify triglyceride contamination in pure water. This approach ensures the accuracy of biochemical test results and highlights the importance of monitoring pure water quality in laboratory settings.