Luoyang Yuboo Testing Technology Co., Ltd.
18 Common Testing Instrument Sample Delivery Requirements
Release Time:
2024-01-08 17:54
Infrared spectroscopy has a wide range of applicability to samples. It has the characteristics of fast detection speed, good repeatability, and low sample consumption. Solid, liquid samples, inorganic, organic, and polymer compounds can all be detected.
Infrared spectroscopy has a wide range of applicability to samples. It has the characteristics of fast detection speed, good repeatability, and low sample consumption. Solid, liquid samples, inorganic, organic, and polymer compounds can all be detected.
The frequency, intensity, and shape of the infrared spectral characteristic bands of compounds will vary with the measurement state and sample preparation method. The key to obtaining accurate information in infrared spectroscopy research is to use different sample preparation methods for different samples.
1. KBr compression method: The test spectrum range is 4000-400cm-1. The sample is dry powder or ground powder, with a dosage of 1-2mg. It can be packed in a small plastic bag or wrapped in weighing paper to send the sample.
2. ATR (Attenuated Total Reflection) method: The test spectrum range is 4000-650cm-1, and the sample is powder, liquid (cannot contain a large amount of water because water has a strong absorption peak), fiber, fabric, etc. Non destructive testing. The sample size is small. If the fabric is cut into 1cm2, only one drop of liquid can be detected.
3. The infrared observation of the temperature variation of the sample can be used in a heating cell (room temperature~300 ° C). The sample can be KBr compression tablets or thin films (approximately 30 μ It can also be directly applied to infrared window sheets (such as KBr sheets) with a thickness of m.
4. Orientation samples (usually thin films) can be measured using infrared polarizers to characterize infrared dichroism.
5. Micro infrared method: Test micrometer level samples (such as monofilament fibers).
Gas mass spectrometry (GC-MS)
Application: It is applicable to qualitative and quantitative analysis of low boiling point and thermal stability, structural analysis and pyrolysis mechanism analysis of small molecular organic compounds and macromolecular compounds with good quality, and can be applied to environmental protection, food, petrochemical industry, biomedicine, metabolomics, essence and flavor and other fields, forensic medicine, tobacco.
Sampling requirements:
1、 Solution:
1. Organic solvent system
If the moisture content in the sample is less than 1 ‰, anhydrous sodium sulfate should be added if necessary to remove the moisture; Most of the components in the sample should be small molecules and volatile organic compounds, with little or no difficult to volatile components (such as polymers and large molecules) with boiling points above 280 ℃; The sample does not contain inorganic acids, bases, or other substances that may damage the chromatographic column.
2. Aqueous solution system
If the moisture content in the sample exceeds 5%, pre-treatment accessories, including headspace sampling (HS) and solid-phase microextraction (SPME), need to be used. Suitable for almost all samples such as aqueous solutions and soil, with a detection range of volatile and semi volatile organic compounds.
2、 Solid:
1. Organic small molecules
If analyzing the volatile components in solid samples, samples can be directly sent; If analyzing the organic components in solid samples, it is generally necessary to extract the organic components using appropriate organic solvents. If the system is complex, further purification is required. Afterwards, in order to improve detection sensitivity, concentration is generally required.
2. Polymer
For the analysis of such samples, it is necessary to crack the attachments. The pyrolysis temperature is between 200 and 750 degrees. If analyzing the volatile components in polymer samples, the pyrolysis temperature is generally set at 200-300 degrees without damaging the main structure of the polymer. If it is necessary to analyze the main chain segment structure of the polymer, the pyrolysis temperature is generally 500-700 degrees, and the specific temperature can be determined based on the TG curve.
Notes:
The pre-processing of GC-MS generally requires reference to relevant literature. If you are unsure, you can call for consultation. The quantitative standards are provided by the customer, and our laboratory only provides conventional organic solvents. This instrument is unable to detect gas samples
Test items
1. Quality testing of raw materials, semi-finished products, and products in the chemical industry
2. Detection of volatile and semi volatile components in various matrices using headspace (HS) and solid-phase microextraction (SPME)
3. Analysis of Polymer Structure and Study on Pyrolysis Mechanism
4. Flavor substances in various foods such as cigarettes, alcohol, and beverages
5. Analysis of essential oil components in plants and traditional Chinese medicine.
6. Solvent residue determination
7. Purity testing
8. Polymer monomer residue
9. Pesticide residue detection
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