FLASH PU FLASH OPTIMIZATION
When scouting TLC solvent systems, it is important to realize a low Rf (0.15 – 0.35) is preferred because a lower Rf means a greater CV. Large CVs indicate increased compound-silica contact time, improving the chances of
component resolution. Since CV is a measure of compound retention, then ∆CV is the measure of compound resolution, (see Figure 2). In FLASH purification, ∆CV dictates the sample load range possible for any given cartridge size, (see Table 1). For two adjacent components, a large ∆CV is desirable.
B
I.
A
O R I G I N
A B R f 0.50 0.40
CV II.
A B R f 0.33 0.20
2.0 2.5
CV III.
A B R f 0.20 0.10
B
A
O R I G I N
3.0
A
B
5.0
10
5.0
O R I G I N
CV
Figure 2. The Rf–CV relationship is illustrated in this graphic. (I) Although compounds A and B are well resolved on TLC with Rf of 0.5 and 0.4, respectively, FLASH purification with the same solvent conditions provides low retention and low resolution (∆CV = 0.5) for A and B, respectively. (II) Lowering the Rf (A = 0.33, B = 0.20) provides increased retention and resolution (∆CV = 2). (III) Extremely high resolution (∆CV = 5) is obtained by further reducing the compounds’ Rf. Cartridge FLASH 12+S
FLASH 12+M
Dimensions (mm x cm)
Typical Flow Rates (mL/min)
Column Volume
Silica Weight
Difficult ∆CV = 1
12 x 15
2.5 – 12
12mL
9g
8 - 40mg
10 – 25
48mL
12 x 7.5
FLASH 25+S
25 x 7.5
FLASH 40+S
40 x 7.5
FLASH 65i
65 x 20
FLASH 25+M FLASH 40+M FLASH 75S
25 x 15 40 x 15
2.5 – 12 10 – 25 25 – 50
300mL
200g
75 x 30
100 – 250
1000mL
500 – 1000
8.6L
FLASH 400M
400 x 30
7000
150 x 60 400 x 60
SNAP 10g
2.1 x 5.5
SNAP 50g
3.9 x 8.1
SNAP 340g
50g
100 – 250
350g
80 - 400mg
400 - 800mg
80 - 400mg
400 - 2000mg
2 - 5g
160 - 800mg
0.8 - 4g
40 - 200mg
300 - 1600mg
3 - 16g
38L
20kg
0.03 - 0.25kg
10 - 20
15mL
10g
8 - 40mg
30 - 50
66mL
20 – 40
39 x 15.7
31 - 50
65 - 100
76L
33mL 132mL 470mL
40kg 25g
800 - 4000mg 6 - 32g
0.06 - 0.50kg 20 -100mg
50g
40 - 200mg
340g
300 - 1600mg
100g
200 - 400mg 800 - 1600mg
2.5kg 5kg
40 - 200mg 160 - 800mg
4.3L
800g
Table 1. Biotage cartridge loading table for isocratic purifications
230
15 - 80mg
400 - 2000mg
7000
500mL
100 - 200mg
400g
3.0 x 7.2
71 x 16.8
470mL
20 - 100mg
30 - 160mg
100 – 250
500 – 1000
SNAP 100g
66mL
Easy ∆CV = 6
4 - 20mg
40g
75 x 9
65 – 85
150 x 30
SNAP 25g
20g
100g
FLASH 150M
FLASH 400L
24mL
132mL
75 x 15
FLASH 150L
4.5g
25 – 50
FLASH 75M FLASH 75L
6mL
Typical ∆CV = 2
80 - 400mg
200 - 1000mg
1 - 2g
1.6 - 8g
8 - 20g
2 - 10g
10 - 20g
16 - 80g
80 - 160g
4 - 20g
4 - 10g
20 - 40g
32 - 160g
160 - 320g
0.5 - 2.0kg
2 - 4kg
0.25 - 1.0kg
40 - 200mg
1 - 2kg
200 - 400mg
100 -200mg
500 – 1000mg
400 - 2000mg
2 - 5g
200 - 400mg 1.6 - 8g
1 - 2g
8 - 20g