The standard method for hydrazine analysis published by the National Institute of Occupational Safety and Health (NIOSH) presented a methodology I found a little bit confusing. The first four steps of the procedure are as follows: SAMPLING: 1. Connect the outlet of the sampler and the inlet of the pump to a tube packed with glass wool to protect the pump from splashover. 2. Calibrate the personal sampling pump with sampler in line. 3. Sample at 0.2 to 1.0 L/min for a sample size of 7 to 100 L. 4. Transfer the solution from the bubbler to a glass vial, rinsing both the bubbler stem and body with 1-mL portions of 0.1 M HCl. Cap the vial securely for shipment. Also, is there any alternative method for measuring hydrazine using gas chromatography flame ionization detectors (GC-FID)? I am having a difficult time visualizing step 1 in particular. Is there anyone that may help provide clarification, hopefully with a diagram of some sort? It would be very much helpful. Thank you and have a good day!