Article Figures & Data
Figures
- FIGURE 1.
The results of 134 elutions using 70:30 methanol:water. These trials included 21 preparations of <90% purity. The high correlation coefficient (0.99) shows a large strength of association between the silica-cartridge method and the ITLC method.
- FIGURE 2.
The numbered impurities are 99mTc-gluconate and HRTc (peak 1), unknown (peak 2), reduction impurity (maybe a Tc(IV) product) (peak 3), unknown (peak 4), high-purity Tc(V)O2(TF)2 (peak 5), Tc(III)Cl2(TF)2 or Tc(I)(TF)3 (peak 6), and 99mTcO4 (peak 7). Any variance among Rf values may be large enough to be the difference between the passing and failing of a QC sample with impurities lying near a cut line Rf of 0.2.
- FIGURE 3.
Sample volume effect on ITLC. Five-, 10-, and 15-μL spot size profiles are shown from left to right.
- FIGURE 4.
Note the difference in ink color Rf during trials with the same batch of 99mTc-tetrofosmin, time, solvent, lot of ITLC strip, and drop size. Ink had the same variability with and without sample present: 95.8% between Rf 0.2 and 0.8 (top) and 86.2% between Rf 0.2 and 0.8 (bottom).
- FIGURE 5.
99mTc-Tetrofosmin images of the same patient during rest injections. A high-purity scan is shown on the left, and a low purity, 3-h-postpreparation scan, on the right. Both 99mTc-tetrofosmin samples had passed QC testing 30 min after preparation.
- FIGURE 6.
Multiple peaks. Between Rf values of 0.2 and 0.8 lies 94.5% of the activity, whereas only 83% of the activity lies within the main 99mTc-tetrofosmin peak.
- FIGURE 7.
Rest/stress SPECT. Using 99mTc-tetrofosmin with multiple peaks (Fig. 6), 3 nuclear medicine physicians verified the acceptability of these scans.
Tables
Method Replications on the same batch Mean SD Sample variance ITLC 95.60% 90.00% 90.00% 94.00% 94.00% 95.60% 94.00% 94.00% 93.40% 2.08 0.044 Silica cartridge 96.20% 96.70% 96.60% 97.10% 96.90% 96.60% 96.80% 96.40% 96.70% 0.292 0.001 Flow rate Silica cartridge ITLC Ratio S:I 3 94.9 93.3 101.7 3 96.5 94.0 102.6 5 94.0 93.6 100.5 5 97.7 96.9 100.9 5 96.5 93.3 103.4 5 95.5 94.0 101.6 7 93.7 93.3 100.4 7 94.8 94.0 100.8 7.5 93.8 93.6 100.2 7.5 95.9 96.9 99.0 9 91.9 93.3 98.5 9 92.4 94.0 98.3 10 91.3 93.6 97.6 10 90.4 96.9 93.3 Data are percentages.
