Tlc sg al strips

The radiolabeling yield of [¹³¹I]I-peptide was determined by TLC using Whatmann 3 MM strips and MeOH/H₂O (95:5), as eluent. For [^99mTc]Tc(CO)₃-peptide, TLC-SG (Al) strips (Merck; Burlington, MA, USA) using ACN/H₂O (95:5) as eluent were used; and for only [^99mTc][Tc(CO)₃]⁺ complex the radiolabeling yield was evaluated using TLC-SG (Al) strips and 0.9% NaCl, as eluent. The radioactivity was determined by AR 2000 TLC-Scanner (Eckert & Ziegler; Berlin, Germany).
RP-HPLC analyzes were performed on a 1290 Infinity II UHPLC system (Agilent Technologies; Saint Clair, CA, USA) fitted with a radioactivity detector (Eckert & Ziegler; Berlin, Germany) and Open Lab ECM data system (Agilent Technologies; Saint Clair, CA, USA) to confirm the yield and purity of both radiolabeled peptides. Analyzes were performed using a Phenomenex C18 column (150 × 46 mm; 5 µm particle size; 300 Å pore size), detection at λ = 220 nm, using 0.1% TFA:H₂O as solvent A and 60% acetonitrile/0.1% TFA:H₂O as solvent B. A gradient of 5% to 95% of solvent B in 30 min was used at a flow rate of 1.0 mL·min⁻¹.

Radiochemical purity was evaluated by ascendant chromatography (n = 9) and RP-HPLC.
Ascendant chromatography was performed by TLC-SG (Al) strips (Merck) using 95% ACN as an eluent. The radioactivity was determined with an AR-2000 radio-TLC Imaging Scanner (Eckert & Ziegler, Germany).
RP-HPLC analyses were performed on a 1290 Infinity II UHPLC system (Agilent Technologies, Santa Clara, CA, USA) equipped with a radioactivity detector (Eckert & Ziegler, Germany) and Open Lab ECM data system (Agilent Technologies, Santa Clara, CA, USA). The analytical column was a Phenomenex Kinetex^® Reversed Phase C₁₈ (100 mm × 3 mm; 2.6 µm) maintained at 30 °C. Mobile phase A was 0.1% (v:v) TFA in water. Mobile phase B was 0.1% (v:v) TFA in MeOH. The gradient of mobile phase B was: 10% (0.0−1.0 min); 10−90% (1.0−8.0 min); 90% (8.0−10.5 min); and 90−10% (10.5−12.0 min). The flow rate was 0.8 mL^.min⁻¹ and the UV detector was set at 284 nm.