LC-6890A AutomaticHead Space SamplingimplementIt is a new type of gas chromatograph sample pretreatment equipment with multiple innovations and intellectual property rights. We know that in the daily analysis process of gas chromatography, 10% of the error size * comes from the instrument being operated, while 90% comes from the quality of sample pretreatment. The advantages and disadvantages of different sample pretreatment techniques and methods vary greatly. Among them, if headspace injection (gas phase extraction) gas chromatography analysis is used, it can achieve accurate, simple, and rapid analysis of volatile compounds in almost any sample. Because headspace sampling makes it extremely easy to achieve solvent-free extraction of liquid and solid samples, it can be said to fundamentally eliminate errors and problems that may occur in sample pretreatment methods such as adsorption desorption and solvent extraction.

1The headspace injection gas chromatography analysis method has the following advantages compared to direct injection, solvent extraction, and adsorption desorption injection methods:

⑴ Accurate, simple, fast, convenient, automatic, and environmentally friendly;

⑵ High sensitivity analysis of volatile components in samples;

Due to the fact that high boiling point components are not introduced into GC, analysis time can be shortened and work efficiency can be doubled;

Due to the fact that high boiling point components are not introduced into GC, it avoids contamination of the analysis system by high boiling point components, thereby reducing the daily maintenance work of the instrument and extending the life of certain key components (such as injectors, chromatography columns, detectors, etc.);

IIThe application fields and examples of headspace injection gas chromatography analysis at home and abroad can be divided into the following categories:

(1) Petrochemical industry: high polymer monomer coatings, volatile organic compounds, etc;

⑵ Environmental science: volatile halogenated hydrocarbons in drinking water and organic toxic volatile compounds in industrial wastewater;

⑶ Hygiene and epidemic prevention: analysis of residual disinfection and fumigation of medical supplies;

⑷ Food industry: quality control of colored wine, vinegar, soy sauce, residual acetaldehyde in packaging materials, and residual 6 # solvent in extracted oil;

(5) Spice essence: flavor analysis in beer and tea;

(6) Quality inspection of drugs: organic residual solvents in drugs;

Forensic chemistry: determination of ethanol, ketones, and aldehydes in blood and urine;

Other: such as volatile organic compounds in soil;

III LC-6890AAutomatic TypeHead Space SamplingimplementCharacteristics and main functions ：
1. Integrated design, compact structure, easy to operate;
2. Metal isothermal body heating and temperature control, with high temperature control accuracy, small gradient, good temperature stability, simple and reliable, reducing various drawbacks that may be caused by oil bath heating and constant temperature;
3. Microcomputer control, LCD Chinese character display, membrane keyboard, numerical input, main functions include:
⑴ LCD can display: method parameter settings, real-time working status, running time, year, month, day, hour, etc. at a glance;
⑵ The headspace bottle, injection valve system, and sampling (injection) transfer tube are all separately heated and temperature controlled;
⑶ Three external affairs, 8-level time program control, running self start and self stop;
⑷ It has 9 methods for editing, storing, and calling at any time, achieving fast startup and analysis;
⑸ The GC and chromatographic data processing workstations can be synchronously started, and the device can also be started using external event programs;
4. Equipped with an external carrier gas regulation system, the GC instrument can be used for headspace sampling analysis without any modifications or changes. The original instrument carrier gas can also be used;
5. Through time programming, automatic functions such as pressurization, sampling, injection, analysis, and post analysis blowback cleaning can be achieved;
6. The use of pressure equilibrium injection technology for headspace injection can result in narrow chromatographic peak shapes;
7. The sample transfer tube and injection valve have automatic blowback function, which avoids cross contamination of different samples;
8. For active substance analysis, an elastic quartz tube can be selected as the sample transfer tube;
9. The injection volume can be adjusted at any time according to the concentration of the sample to be analyzed by the customer;
10. Easy to achieve multiple repeated injections of the same sample bottle, facilitating the development and research of methods;
11. The key components used for driving are imported pneumatic components;
12. The injection needle is easy to replace and can be connected to all models of GC both domestically and internationally;
four．LC-6890AAutomatic TypeHead Space SamplingimplementMain technical parameters of pressure balance injection:
1. Temperature control range in the sample area:
Room temperature -350 ℃, with an increment of 1 ℃, set heating power of approximately 400W;
2. Temperature control range of valve injection system:
Room temperature -180 ℃, with an increment of 1 ℃, set heating power of approximately 60W;
3. Temperature control range of sample transfer pipeline:
Room temperature -200 ℃, with an increment of 1 ℃, the heating power is approximately 40W;
4. Temperature control accuracy:<± 0.5 ℃;
5. Temperature control gradient:<± 0.5 ℃;
6. Headspace bottle workstation: 9;
7. Headspace bottle specifications: optional 20ml, 10ml (50ml and other specifications can be customized);
8. Repeatability: RSD<1.5% (ethanol in 200ppm water, N=5）；
9. Injection volume control mode: Injection time and pressure control the injection volume;
10. Injection pressure range: 0-0.4Mpa (continuously adjustable);
11. Backblowing cleaning flow rate: 0-200ml/min (continuously adjustable);
12. Effective size of the instrument: 180 × 360 × 400mm3;
13. Weight of the instrument: approximately 12 kg.