Figure 6.

Analysis of seven common nitrosamines including NDMA, NDEA, NEIPA, NDIPA, NDBA, NMPA, and NMORP using FE-SHSGC-NPD. The carrier gas is helium at constant flow rate at 2 mL/min. The oven temperature is held at 70°C for 1 min, then ramped by 25°C/min to 240°C, and finally held at 240°C for 1 min. The diluent contains 20 mg/mL pyrogallol and 0.1% phosphoric acid in IPA. The standard solution contains 500 ng/mL each of NDMA, NDEA, NEIPA, NDIPA, NDBA, NMPA, and NMORP, and 40 μL is added to a 20-mL headspace vial, capped and crimped tightly. The vial is heated at 150°C for 30 min, and 1 mL headspace is injected with a split ratio of 20:1