Optimisation of Water Quality for Clinical Chemistry Laboratories

The Importance of Water in Clinical Chemistry

Water is at the centre of clinical testing. If laboratories utilise water for sample preparation or reagent dilution, its purity directly influences test results. A minor impurity may lead to an erroneous outcome. This can affect patient treatment and prognosis. Laboratories must monitor water quality. Reproducing test results depends on consistent water purity. Contaminants may cause tests to fail. In clinical analysis, water is not merely a solvent. It is a component that may alter a diagnosis. Every stage of testing depends on water free from impurities to ensure accurate and reproducible results.

Water Quality Standards for Clinical Laboratories

Clinical laboratories follow strict guidelines established by organisations such as the Clinical and Laboratory Standards Institute and the College of American Pathologists.

These guidelines specify acceptable water purity levels.

Different water grades are used in laboratories according to specific testing requirements. Type I water is the most pure grade.

Type I water is employed for critical analyses where any contamination may affect test results.

Type II water is used for non-critical procedures. Type III water, also known as reagent water, is employed for less sensitive tests. Each water grade is designated for a particular use within the workflow. These specifications assist laboratories in verifying daily water quality. They also provide assurance across repeated tests and instrument calibrations. In the absence of standard guidelines, maintaining quality control would be challenging.

Water Purification Technologies

Various purification technologies maintain water purity. Reverse osmosis purifies water by forcing it through membranes with very small pores, thereby retaining larger particles and molecules. Deionisation utilises ion‐exchange resins to remove dissolved ions efficiently. Ultraviolet treatment decomposes organic compounds present in the water. Ultrafiltration removes particles at the nanometre scale. Distillation produces pure water by boiling and condensing the steam. In some cases, both techniques are combined. In point‑of‑use systems, water is filtered before entering an instrument. This method is standard in modern laboratories to ensure water quality.

Water's Role in Quality Control

Water purity directly impacts quality control measures. Water is often mixed with reagents, calibrators and controls. Impure water may contaminate these substances. Heavy metals, bacterial deposits and trace organic chemicals are common contaminants. They may interfere with enzyme activity and spectral measurements. Even minimal contamination can alter quality control baselines. Laboratories follow strict protocols for monitoring water purity. Routine analyses detect changes in water composition. If an issue is identified, corrective measures are promptly implemented. Such monitoring reduces errors in routine testing.

Conclusion

Water quality is a fundamental factor in clinical chemistry. All stages of testing—from initial sample handling to final quality control—depend on water that is free from impurities. Regulations determine the appropriate water grade for each application. Purification methods such as reverse osmosis, deionisation, ultraviolet treatment, ultrafiltration and distillation work together to produce pure water. For more tech information and support, please check Stanford Advanced Materials (SAM).

Frequently Asked Questions

F: Why is water used in clinical chemistry laboratories?

Q: Water functions as a solvent and influences test precision and accuracy in clinical analysis.

F: What types of laboratory water are used in clinical applications?

Q: Laboratories use Type I, Type II and Type III water, each designated for specific testing requirements.

F: How does water quality affect quality control?

Q: Impure water may contaminate reagents and calibrators, thereby affecting test accuracy.