Halogen detection is an important test item in chemical analysis, which is mainly used to detect the halogen content of fluorine (F), chlorine (Cl), bromine (Br) and iodine (I) in samples. Halogen testing is of great significance for environmental protection, food safety, medical and health care, and other fields. This article will introduce the standards and methods for halogen detection.
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1. Halogen testing standards.
The standards for halogen testing are based on the relevant standards established by the International Organization for Standardization (ISO), as well as the regulations and standards of various countries and regions. Here are some common halogen testing standards:
1.ISO 14501:2006 Plastics - Method for Determination of Chlorine, Bromine and Fluorine in Plastic Samples.
2.ISO 17294-1:2017 Soil quality - Determination of iodine, bromine, chlorine and fluorine content in soil.
3.ISO 17294-2:2017 Soil quality - Standard method for the determination of iodine, bromine, chlorine and fluorine in soil.
4.ISO 17295-1:2017 Drinking water - Part 1: Determination of chlorine, bromine, iodine and fluorine content.
5.ISO 17295-2:2017 Drinking water - Part 2: Determination of chlorate and fluoride.
6. gb/t 5750.10-2006 Standard Test Methods for Drinking Water Determination of Halogen Content in Sensory Properties and General Physical and Chemical Indicators.
2. Halogen detection methods.
At present, there are several methods for halogen detection:
1.Atomic Absorption Spectrometry (AAS).
Atomic absorption spectrometry is a commonly used method for the detection of halogens. The principle is to convert the halogen elements in the sample into an atomic state, and the halogen content is calculated by measuring how well a specific atom in the sample absorbs light. This method has high sensitivity and accuracy, but requires expensive instrumentation and specialized operators.
2.Ion-selective electrode method (ISE).
The ion-selective electrode method is an electrochemical analysis method suitable for the determination of chlorine, bromine, and iodine ions in a sample. The principle of this method is to measure the ion concentration at a certain potential using a specific ion-selective electrode. This method is easy to operate, but it requires calibration with standard solutions and is less sensitive for the determination of iodine ions.
3.Gas chromatography (GC).
Gas chromatography is a method for separating and analyzing different components in complex samples and is commonly used for the determination of organohalogen compounds in samples. The principle of this method is to separate the organohalogen compounds in the sample through a gas chromatography column and then detect them through a detector. This method has high separation efficiency and sensitivity, but requires complex sample preparation.
4.High Performance Liquid Chromatography (HPLC).
High performance liquid chromatography (HPLC) is a method for separating and analyzing different components in complex samples and is commonly used for the determination of organohalogen compounds in samples. The method works by separating organohalogen compounds in a sample through a high-performance liquid chromatography column and then passing them through a detector. This method has high separation efficiency and sensitivity, but it requires complex sample preparation and expensive instrumentation.
5.Fluorescence spectroscopy (FS).
Fluorescence spectroscopy is an analytical method based on the luminescence properties of fluorescent substances and is commonly used to determine the fluorine content of samples. The principle of this method is to use a specific wavelength of light to excite fluorine in a sample to make it fluoresce, and the fluorine content is calculated by measuring the intensity of the fluorescence. This method has high sensitivity and accuracy, but requires expensive instrumentation and specialized operators.
In summary, there are various standards and methods for halogen testing, and it is necessary to choose the appropriate method according to the specific testing needs. At the same time, in order to ensure the accuracy and reliability of the test results, it is also necessary to pay attention to the collection, storage, preparation and handling of samples, as well as to comply with the safety norms and operating procedures of the laboratory.