The detection properties of silicone rubber can be said to be between organic and inorganic substances. It contains a variety of small molecules and polymers, and the environment of food contact silicone rubber is complex and diverse.
The analysis and detection of toxic substances in silicone rubber can be roughly divided into two ways. One is to directly and qualitatively detect the presence of toxic substances in silicone rubber materials. Secondly, by analyzing the molecular structure changes of silicone rubber before and after aging, the aging mechanism is deduced to determine the possible toxic substances. At present, analytical methods such as infrared spectroscopy and nuclear magnetic resonance are usually used to infer the aging mechanism of silicone rubber, which is simple and fast.
1. Silicone rubber detection methods - gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS)
Currently, GC and GC-MS have become the most commonly used methods for the qualitative and quantitative detection of silicone rubber for volatile cyclosiloxanes in food-contact silicone rubber. This method mainly takes advantage of the strong chromatographic separation ability and high resolution of mass spectrometry, and is suitable for the separation and analysis of volatile complex components.

2. Silicone rubber detection method - Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR)
FTIR and NMR are important tools for analyzing the organic structure of silicone rubber materials. Among them, infrared spectroscopy is an important method to identify the composition of silicone rubber materials. NMR can obtain information about its molecular skeleton structure, and they are widely used in the study of the microstructure of silicone rubber.
At present, the NMR detection of silicone rubber is mainly used in the medical field, industrial field and biological field.


3. Silicone rubber detection method - thermal analysis (TGA)
Thermal analysis is the measurement of the properties of a substance at a set temperature as a function of temperature or time. Thermogravimetric analysis (TGA) is a technique for measuring the mass-temperature relationship of a substance under programmed temperature control. According to relevant literature reports, thermogravimetric analysis can be used to study and detect the thermal degradation process of silicone rubber at high temperature, determine its thermal stability, and analyze the possible migration of toxic substances.
The TGA method was used to detect thermal degradation products of polydimethylsiloxane and montmorillonite nanocomposites.

4. Silicone rubber detection method - inductively coupled plasma mass spectrometry and atomic absorption method
In addition to aging and decomposition to produce low-molecular-weight cyclosiloxane and other toxic substances, due to long-term contact with food, heavy metal ions in addition to silicone rubber products will gradually migrate into food, enrich the human body, and pose a threat to human health.

Source:j检测狗
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