Reagents and Materials:

- Chloroform, GC grade

- Helium, carrier gas

- Flame ionization detector (FID)

Procedure:

1. Prepare a 10 ppm standard solution of chloroform in hexane.

2. Inject 1 µL of the standard solution into the GC.

3. Run the GC using the following conditions:

- Column: DB-5 (30 m x 0.25 mm x 0.25 µm)

- Temperature program: 40 °C (hold for 5 min) - 220 °C (at 10 °C/min)

- Detector temperature: 250 °C

- Carrier gas flow rate: 1 mL/min

Analysis:

1. Identify the chloroform peak by comparing its retention time to that of the standard.

2. Calculate the purity of the chloroform sample by comparing the area of the chloroform peak to the total area of all peaks in the chromatogram.

The purity of the chloroform sample should be greater than 99.9%.