Added organic solvent content, S, v/v

Approximate final dilution factor

0.2 (20%) 1.25 (80%)
0.3 (30%) 2.15 (47%)
0.4 (40%) 3.3 (30%)
0.5 (50%) 5 (20%)
0.6 (60%) 7.5 (13%)
0.7 (70%) 12 (8.6%)
0.8 (80%) 20 (5%)
0.9 (90%) 45 (2.2%)
Table 2: Final sample dilution factor as a result of two step purification. After methanol precipitation, additional sample dilution is caused by the necessity of reducing the content of organic solvent to the desired concentration (20% in this particular case, s=0.2). This “double dilution” results in very fast analyte content decline per sample volume, as given by the relationship: f=(1-S)(s/S). The values are reported without taking into account a correction for volumes non-additivity.