Determination of headspace gas content in plastic packaging container for food
— Sensor method
1 Scope
This document describes the determination of headspace gas content in plastic packaging container for food by sensor method.
This document is applicable to the determination of oxygen, carbon dioxide and other gases in food plastic, plastic and other composite material packages that can be pierced by sampling needles. The determination of headspace gas in other airtight packaging containers can be carried out with reference to this document.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute indispensable requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 2918 Plastics - Standard atmospheres for conditioning and testing
ISO 2602:1980 Statistical interpretation of test results - Estimation of the mean - Confidence interval
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
3.1
headspace gas
a certain amount of gas left or filled into the package after the package containing food is sealed
Note: Depending on the packaging method, the pressure of the gas inside the package may be equal to or higher than the ambient atmospheric pressure, or lower than the ambient atmospheric pressure.
4 Principle
Insert the sampler into the package to be tested, and collect a sufficient volume of sample gas from the headspace in the package. Introduce the sample gas into the gas analysis sensor, and record the test data after a certain test time interval or after the gas concentration value output by the gas analysis sensor is stable.
Corresponding gas analysis sensors shall be used for the determination of different gas contents. For example, when determining the oxygen content in the sample gas, the sample gas shall be introduced into the oxygen analysis sensor; when determining the carbon dioxide content in the sample gas, the sample gas shall be introduced into the carbon dioxide analysis sensor.
For the package filled with high purity nitrogen, the headspace nitrogen content in the package can be obtained by deducting the oxygen content, carbon dioxide content and other known gas content from the total gas content.
5 Sample preparation
The package shall be free from obvious defect and leakage and sealed well. The number of samples shall meet the test requirements and be no less than 5.
6 Apparatus
6.1 Headspace gas analyzer
The headspace gas analyzer shall be capable of automatic sampling, and shall consist of sampling needle, sample injection port, gas analysis sensor, pipeline, etc. See Figure 1 for the schematic diagram.
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Sample preparation
6 Apparatus
7 Calibration
8 Test procedure
9 Result calculation
10 Expression of results
11 Test report
