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

Figure 1 Spot urine iodine concentration detected by As³⁺-Ce⁴⁺ catalytic spectrophotometry on January 14 by on a Beckman Coulter AU5800. A and B: Appearances of the reacted solution of the original urine specimen (A) and its 2-, 5-, 10-, and 20-fold serial dilutions after digestion at 100 °C for 60 min (B); C: Ce⁴⁺ absorbance curve of the original urine specimen.

Figure 2 Ce⁴⁺ absorbance curves of two specimens during admission-discharge procedures to calculate the actual spot urine iodine concentrations. A-C: Original random urine specimen on January 15 (preoperation) (A) and its 10- (B) and 100-fold (C) dilutions; D-F: Original random urine specimen on January 17 (1 d before discharge) (D) and its 10- (E) and 100-fold (F) dilutions.

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).