Question

Measure the width of the${}^{\mathbf{35}}\mathbf{C}{\mathbf{1}}^{\mathbf{-}}$ peak at half-height in Figure 26-32 and calculate the plate number. The capillary length to detector was 40.0 cm. Find the plate height.

Short answer

The plate number $\mathrm{N}=1.35\times {10}^4$and plate height$\mathrm{h}=30\mathrm{\mu m}$

Step-by-step solution

Calculate the plate number

Calculating the plate number

$$\begin{gathered} \mathrm{N}=\frac{5.55{\mathrm{t}}_{\mathrm{r}}^2}{{\mathrm{w}}_{1/2}^2} \\ \mathrm{N}=\frac{5.55{\left(39.9\min \right)}^2}{\left(0.81\min \right)} \\ \mathrm{N}=1.35\times {10}^4\mathrm{plates} \end{gathered}$$

Step 2:Calculate the plate height

Calculating the plate height

$$\begin{gathered} \mathrm{h}=0.400\mathrm{m}\times \left(1.35\times {10}^4\mathrm{plates}\right) \\ \mathrm{h}=30\mathrm{\mu m} \end{gathered}$$