Right time to detect urine iodine during papillary thyroid carcinoma diagnosis and treatment: A case report

Figure 3 Detection of the iodinated contrast media reagent iohexol by As³⁺-Ce⁴⁺ catalytic spectrophotometry. A and B: Solution appearances before (A) and after digestion at 100 °C for 60 min (from left to right: 175 mg, 35 mg, and 3.5 mg) (B); C and D: Ce⁴⁺ absorbance curve of 5-fold dilution of urine specimen on January 14 (C) or of 3.5 mg iohexol (D).