Detection target
Determination of Nitrogen Content in Food Additives
Introduction
Nitrogen (N2) is an important food additive (processing aid) and packaging gas in the food industry, primarily used for gas filling, preservation, and protection during food packaging and processing. Due to its inertness, odorless, colorless nature, and its status as a major component of the atmosphere, it is widely used in the packaging of puffed foods, edible oils, dairy products, etc. By displacing oxygen, it slows down oxidation and inhibits microbial growth, thereby maintaining food quality and taste. Because it usually escapes from the food after use, leaving little or no residue, and does not chemically alter the food itself, it is widely recognized internationally as a safe method of preservation and protection.
The main tests involve checking its purity and filling ratio in food packaging, as well as ensuring strict adherence to the usage guidelines for processing aids, to guarantee its effectiveness and prevent risks introduced by impurities or improper use.
Overview
This solution conforms to the GB 29202 National Food Safety Standard Food Additive – Nitrogen. Zirconia is used as the detector in the gas chromatograph. The components to be measured in the sample gas—hydrogen, oxygen, methane, and carbon monoxide—are separated by the chromatographic column and then enter the detector, generating corresponding chromatographic peak signals. Quantitative analysis is then performed using the external standard method. This standard applies to food additive nitrogen produced by cryogenic air separation nitrogen generation, pressure swing adsorption nitrogen generation, membrane separation nitrogen generation, and small-scale specialized nitrogen generators.
Apparatus
GB 29202 Gas Chromatograph for Nitrogen, Food Additive

Configuration
Serial | Name | Configuration | Purpose | Number |
1 | Gas Chromatograph | FID | Analysis of H2, O2, CO, CO2, CH4 | 1 set |
Analysis of CO, CO2, CH4 | 1 set | |||
2 | Chromium Oxide Detector | ZD | Detection of H2, O2 | 1 set |
3 | Methanizer Converter | NI | Conversion of CO, CO2 | 1 set |
4 | Chromatography Column | Special 5Å | Dedicated column | 1 pc |
5 | Chromatography Column | Special TDX-502 | Dedicated column | 1 pc |
6 | Standard Gas | National Standard | Instrument calibration | 1 bottle |
7 | High-Purity Hydrogen Generator | Supply of hydrogen (support gas) | 1 set | |
8 | Air Generator | Supply of air (support gas) | 1 set | |
9 | Chromatography Software | HW-2000 | Data processing | 1 set |
10 | Sampling Cylinder | 2L | Gas sampling device | 1 set |
11 | Computer + Printer | Standard configuration | Brand-specific | 1set |
12 | High-Purity Argon + Regulator | Purity: 99.999% | Carrier gas | 1 set |

