Chapter 25: Q33P (page 710)

(a) use figure 25-28a select a tetrahydrofurn/water mobile phase strength of equivalent strength to 80%methanol.
(b)Describe how to prepare 1 L of this tetrahydrofurn mobile phase.
(c)what limitation would be imposed by the use tetrahydrofurn.

Short Answer

Expert verified

a) 53%

b)To prepare 1 L of this tetrahydrofuran mobile phase (53 %), we need to mix 530 mL of tetrahydrofuran with 470 mL of water.

c) The limitations that would be imposed by the use of tetrahydrofuran is that it absorbs UV radiation and attacks polyether, ether, ketone and plastic components.

Step by step solution

Definition of water mobile phase of equivalent strength

The weak solvent is commonly referred to as the A-solvent (percent A), and the strong solvent is referred to as the B-solvent ( percent B). The mobile phase is typically a mixture of A- and B-solvents, such as 40% buffer and 60% methanol (abbreviated 60 percent B).

a) Figure 25-28 depicts a nomograph of the volume percentage of solvents with the same eluent strength.

At the same eluent strength, a vertical line intersects each solvent line.

Tetrahydrofurn mobile phase

b) The figure shows that 53 percent of the tetrahydrofuran/water mobile phase strength is equivalent to a concentration of 80% methanol.

To prepare 1 L of this tetrahydrofuran mobile phase (53%), we need to mix 530 mL of tetrahydrofuran with 470 mL of water.

Limitations of tetrahydrofuran

c) The limitations that would be imposed by the use of tetrahydrofuran is that it absorbs UV radiation and attacks polyether, ether, ketone and plastic components.