The aim of this work is to study the influence of contamination with infusion in clinical chemistry tests and to design an algorithm for detection of inadequate blood specimen. We show that panic value of postassium (K+)/ glucose (GLU) or decrease of total protein (TP), albumin (ALB), urea nitrogen (BUN), uric acid (UA), high-density lipoprotein cholesterol (HDL-C), total cholesterol (T-CHO), and calcium (Ca) is an index of contamination of drip infusion solution. Through a clinical study, we show that our algorithm is useful for preventing adverse medical errors.