"Sensor Method for Determination of Headspace Gas Content in Food Plastic Packaging Containers" solicits opinions

 

This standard is drafted in accordance with the provisions of GB/T 1.
1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents"
.
This standard was drafted by: Beijing Institute of Product Quality Supervision and Inspection, Jinan Languang Electromechanical Technology Co.
, Ltd.
, Foshan Shunde Tepugao Industrial Co.
, Ltd.
, Ganjiang New Materials Co.
, Ltd.
, Jiaxing Xingyue Packaging Materials Co.
, Ltd.
, Wuhan Xudong Foods Co.
, Ltd.
, Beijing Jisi Juyuan Information Technology Co.
, Ltd.
, Hangzhou Xingdian Packaging Materials Co.
, Ltd.
, Beijing Crestar Technology Co.
, Ltd.
, China Nutrition and Health Food Association, Beijing Institute of Science and Technology Analysis and Testing Institute, Jinan University, National Center for Food Safety Risk Assessment, Institute of Agricultural Quality Standards and Testing Technology, Chinese Academy of Agricultural Sciences
.

 

　　This standard describes the use of sensors to determine the content of different headspace gases in plastic food packaging containers
.
This standard is applicable to the determination of the content of oxygen, carbon dioxide and other gases in food plastics that can be pierced by sampling needles and the packaging of composite materials of plastics and other materials
.
The detection of headspace gas in airtight packaging containers of other materials can be carried out with reference to this document
.

 

　　Method principle:
 

　　Insert the sampler into the package to be tested, and collect a sufficient volume of sample gas from the headspace of the package
.
The sample gas is introduced into the gas analysis sensor, and the test data is recorded after a certain test time interval or after the gas concentration value output by the gas analysis sensor is stable
.

 

　　The detection of different gas content should use the corresponding gas analysis sensor
.
For example, when detecting the oxygen content in the sample gas, the sample gas should be introduced into the oxygen analysis sensor; when detecting the carbon dioxide content in the sample gas, the sample gas should be introduced into the carbon dioxide analysis sensor
.

 

　　For a package filled with high-purity nitrogen, the nitrogen content in the headspace of the package can be obtained by subtracting the oxygen content, carbon dioxide content and other known gas content from the total gas content
.

 

　　equipment:
 

　　1.
Headspace gas analysis device
.
The headspace gas analysis device should realize automatic sampling, including sampling needle, injection port, gas analysis sensor, pipeline,
etc.
2.
Sampler
.
It is used to puncture the sample and extract the sample gas to be tested from it, and the sampling error should be less than 1% (volume fraction)
.
Including sampling needle, filter and handle three parts
.
3.
Filters
.
It is used to filter the impurity components in the sample gas to be tested entering the gas analysis sensor, so as to prevent impurities from causing damage to the sensor or affecting the accuracy of the test data
.
4.
Gasket
.
The auxiliary sampler pierces the packaging to avoid rupture of the packaging material
.
If the elasticity of the packaging material of the site to be sampled is sufficient to prevent leakage when the sampler is pierced, the gasket may not be used
.
5.
Injection port
.
Through the injection port, the sample gas in the sampler can be introduced into the detection device
.
6.
Sensor
.
Accurately detect the content of specific gases in the sample gas, and the detection accuracy does not exceed ±0.
5% (volume fraction)
.
7.
Piping
.
The gas flow path for delivering the sample gas to be tested
.

 

　　Calibration:
 

　　Use standard gas for device calibration, and the calibration of different gas analysis sensors should use the corresponding standard gas
.
When calibrating from standard gas
 

　　The gas extracted from the source is introduced into the detection equipment, and the sensor should be calibrated with standard gases of different gas concentrations
.

 

　　Usually, various gas analysis sensors use 99.
99% nitrogen standard gas for zero calibration
.
The carbon dioxide analysis sensor needs to use different concentrations of carbon dioxide standard gas according to the sensor range during the calibration process.
The analytical sensor with three ranges of 0%~100%, 0%~20%, 0%~5% can use 25% and 10% respectively.
, 3% carbon dioxide standard gas calibration; oxygen analysis sensor using 21% oxygen standard gas calibration
.

 

　　experiment procedure:
 

　　1.
According to the requirements of GB/T2918, the test is carried out in a laboratory environment of 23℃±2℃ and relative humidity of 50%±10%
.
If there are other test requirements, it can be tested under the specified environmental conditions
.

 

　　2.
Stick the gasket to the part to be tested of the sample, pay attention to stick it firmly to prevent air leakage
.

 

　　3.
After the sample is stably placed, pierce the sampling needle through the middle of the sealing gasket and enter the package to avoid the sampling needle sticking to the items in the package, causing the needle to be blocked or broken
.

 

　　4.
Use a sampler to collect sample gas from the inside of the package, and the sample gas volume should meet the minimum sample gas volume requirements of the headspace gas analysis device
.

 

　　5.
To prevent the needle from inhaling the gas in the non-packaging container, the sampling needle cannot be pulled out from the packaging, and quickly introduce all the gas to be tested in the sampler into the detection device through the injection port
.
The sample gas will enter the oxygen analysis sensor, carbon dioxide analysis sensor and other gas analysis sensors in turn through the injection port and pipeline
.
Record the test data after a certain test time interval (the length of the test time depends on the response time of the gas analysis sensor) or the corresponding gas concentration value (expressed as volume fraction (%)) output by the corresponding gas analysis sensor to be tested is stable
.

 

　　(Original title: "Sensor Law for Determination of Headspace Gas Content in Food Plastic Packaging Containers" for comments)