The NG-M series LCMS nitrogen generator is a specialized laboratory gas source equipment designed for on-site production of high-purity nitrogen for liquid chromatography-mass spectrometry (LC-MS). It utilizes ambient air as the raw material and produces gas locally, replacing liquid nitrogen cylinders/high-pressure nitrogen cylinders, and continuously supplying gas to the mass spectrometer ion source.

Three major gas usage scenarios for LC-MS:

1. Nebulizer Gas

Spray nitrogen around the needle, shear the liquid phase effluent, tear it into micron-sized droplets, stabilize the electrospray cone, and ensure a pressure of 0.5~0.7 MPa and a purity of ≥99.5%.

Flow rate: Conventional HPLC 2-5 L/min, ultra-high pressure/high flow rate 5-8 L/min.

2. Drying Gas (Auxiliary Gas, heated to 300-500℃)

The package undergoes high-temperature purging of fog droplets, rapidly evaporating the methanol/water mobile phase solvent, and generating gaseous charged ions through desolvation. Incomplete solvent removal can lead to a high baseline and a significant drop in sensitivity.

Single mainstream unit: 10-25 L/min, which is the largest air consumption path of the entire machine.

3. Curtain Gas (also known as Back Blowing Gas, commonly used by Shimadzu)

A nitrogen barrier is formed at the front end of the conical hole: it isolates air, water vapor, and neutral impurities, blocks unvaporized droplets from entering the mass spectrometry vacuum area, reduces baseline noise, and minimizes salt deposition contamination on the conical hole.