The user purchases a gas chromatograph . If it is required to be used normally, in addition to the equipment necessary for routine laboratories such as: laboratory bench, glassware, sample processing equipment, etc., the following parts are also required: gas source, host, Chromatography workstations, columns, standards, and other (computers, printers, etc.).
So the question is, how do you choose these parts for the user? Our Shandong Luchuang Analytical Instrument Co., Ltd. will introduce how to configure a simple gas chromatograph for customers. First introduce the choice of the two main gas sources and mainframes.
I. Gas source 1. Classification and selection of gas chromatograph gas source: According to the application, it can be divided into four categories: carrier gas, gas, gas, and driving gas.
Carrier gas: Through the entire analysis system, high purity and good quality are required. Generally speaking, we require customers to use gas generators or cylinder gas from large manufacturers and good brands. However, with the improvement of technology level, better generators are also a good choice. Good carrier gas is to ensure that the analysis can be carried out normally. basis. Generally used carrier gases are: nitrogen, hydrogen, argon, helium, and the like.
Gas: Generally use hydrogen, as long as it can guarantee normal ignition, and does not interfere with the analysis. Users can use hydrogen generators or high purity cylinder gas. If the budget is sufficient, it is recommended to use a hydrogen generator because it is safer.

Gas-assisted gas: Generally, air is used as long as it can play a role in combustion-supporting, and it does not interfere with the analysis. Most of the air generators are now used.
Drive gas: generally air.
2. How to configure the gas source of the gas chromatograph? When we give the user a gas source, we generally consider it according to the detector:
FID: It needs to be equipped with gas, gas and combustion gas. Generally, it is equipped with nitrogen (high-purity cylinder gas, 40L, with pressure reducing valve or nitrogen generator), hydrogen (hydrogen generator), and air (air generator).
TCD: Requires carrier gas. In general, in order to increase the sensitivity, we recommend customers with high purity hydrogen (hydrogen generator) or helium (high purity cylinder gas). But if the customer wants to analyze hydrogen, we need to equip with argon or nitrogen or helium.
ECD: Requires carrier gas. Generally, nitrogen (recommended high purity cylinder gas).
FPD: Same as FID.
When the customer purchases an automatic valve, it needs to be equipped with a driving gas. Generally speaking, an air cylinder or an air source can be used.
Second, the host <br> Host - gas chromatograph is mainly for the user with two parts: the injection system and detection system.
1. Injection system: As the name implies, where the sample enters, it is also used to vaporize the sample. The injection system often hears the following parts: (1) capillary injector; (2) filling injector; (3) headspace injection; (4) thermal analysis injection; (5) valve advancement kind.
Capillary injector: In general, a normal gas chromatograph will have at least one capillary injector or a filling injector. So we have to configure at least one injector (capillary or padding) when we configure the client. When the customer's analysis needs to be equipped with a capillary column: we provide the customer with a capillary injection sampler; when the customer's analysis requires the use of a packed column: we provide the customer with a filling injector. Our factory instruments can be equipped with up to two capillary injectors or three filling injectors or filling/hair injectors.
Fill the injector: See the capillary injector above.
Headspace injection: headspace injection, thermal analysis, and valve injection are all gas injection techniques. It does not conflict with the sampler, which is based on the injection of the sampler and is additionally allocated according to the customer's requirements. Headspace injection is generally used in the determination of volatile components. In more than 90% of cases, the substance to be tested has a boiling point below 120 degrees Celsius. The sample can be solid or liquid. Commonly used in: determination of ethanol in blood, determination of a volatile component in indoor/in-vehicle decorative materials, determination of various solvent residues, and the like.
Thermal Analytical Injection: Typically used for the detection of certain components in indoor/indoor air. Common analysis: TVOC.
Valve injection: Six-port valve injection, commonly used in gas injection. If the customer's sample is in a gaseous state, the valve is often used for high precision requirements.
2. Detection system: It is a system that converts the collected substances into electrical signals that can be seen on a computer. There are five kinds of detectors commonly used in gas chromatography. According to the substances detected by customers, we need to select a suitable detector. .
TCD: is a general-purpose detector. It has a corresponding property to all materials with different thermal conductivity of the carrier gas, but its sensitivity is not high. Generally, only the percentage of the substance can be detected, and the trace substance of the ppm or ppb level cannot be detected. Commonly used in the detection of permanent gases.
FID: Some people say that it is a general-purpose detector, and some people say it is a special-purpose detector. Responsive to organic compounds, ie C/H compounds. The response to compounds containing heteroatoms is weak. Generally, it can be tested at the ppm level. It is a detector that is widely used at present.
ECD: Electronic capture detector. It is a dedicated detector. Extremely sensitive to substances with strong electronegativity. It is generally used for the detection of compounds containing elements such as chlorobromobromoiodooxy. Can do ppb level detection. It is commonly used in the detection of organochlorine pesticide residues and carbon tetrachloride.
FPD: is a dedicated detector. Significant response to sulfur and phosphorus compounds. The detection level is between ppm and ppb, and the sensitivity is average. It is commonly used in the detection of organophosphorus pesticide residues and hydrogen sulfide and sulfur dioxide.
TSD: Also called NPD, nitrogen and phosphorus detector. It is a special-purpose detector that detects compounds containing nitrogen and phosphorus. More sensitive, the detection level is less common between ppm and ppb, and maintenance is more troublesome.

Zirconium Oxychloride