OMB Meeting Book_9-11-14

particles, centrifuge samples and transfer liquid layer to funnels lined with filter paper. ( 3 ) Sample concentration.— For each sample that will be cleaned

0.00

90

10

0

14.5

90

10

0

4 0-60 a 1 4 0-60 a 1

60-40 a5 9

14.6

0

--5960-40 a

2 76 .0

0

2 67 .1

0

10

90

2 89.9 0

0

10

90

a Appropriate gradient conditions must be established with each column to adequately resolve vitamin B12 and riboflavin and to elute vitamin B12 between approximately 24 and 27 minutes. To establish appropriate gradient conditions with a new column, set the gradient composition at 14.6 and 27.0 minutes to the midpoint of the allowable range from the table above. Inject the resolution test solution and calculate the resolution (R) between the vitamin B12 and riboflavin peaks (See K. Resolution Calculation). Adjust the mobile phase composition at 14.6 and 27.0 minutes until R is > 1.5.

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