Non methane total hydrocarbon gas chromatograph for ambient air

Non methane total hydrocarbon gas chromatograph for ambient airSuitable for the determination of methane, total hydrocarbons, and non methane total hydrocarbons in ambient air. When the injection volume is 1.0 ml, the detection limits (calculated as carbon) of methane, total hydrocarbons, and non methane total hydrocarbons in ambient air determined by this method are all 0.04 mg/m ', and the lower limit (calculated as carbon) is 0.16 mg/m'.

Collect gas samples using sampling equipment and store them in a sample container. Take a portion of the gas sample from the sample container and directly inject it into a gas chromatograph equipped with a hydrogen flame ionization detector. Use two chromatography columns to measure the total hydrocarbon content and methane content (calculated as carbon), and the difference between the two is the content of non methane total hydrocarbons. At the same time, use hydrocarbon removal air instead of the sample to measure the response value of oxygen on the total hydrocarbon column, in order to deduct the positive interference of oxygen in the air on the determination of total hydrocarbons.

Preparation of methane and total hydrocarbon standard series

Using a 100ml syringe (pre filled with a small piece of hard polytetrafluoroethylene), dilute the methane standard gas with diluent gasDilute the body step by step and prepare standard gases with 5 concentration gradients, for example, concentrations of 20%, 40%, 60%, 80%, and 100% of the selected range; Automatic dilution devices can also be used to prepare standard series, or customized standard series can be directly used.

Establishment of standard curve

Extract 1.0 ml of the standard series from low concentration to high concentration, inject it into the gas chromatograph, and analyze the total hydrocarbons and methane separatelyAlkane column separation and hydrogen flame ionization detector detection. Establish calibration curves for total hydrocarbons and methane using methane content (umol/mol) as the x-axis and its corresponding response value (peak area) as the y-axis.

Non methane total hydrocarbon gas chromatograph for ambient airInstrument features:

1.The instrument adopts a fully microcomputer control system, with a large screen LED display in both Chinese and English, providing rich and intuitive display content;

2.New digital design, highly integrated electronic circuit, excellent reliability and anti-interference ability, touch based operation in both Chinese and English, convenient parameter setting and operation.

3.The column box structure is compact, the layout is reasonable, the temperature is uniform, and the intelligent dual channel rear door design makes the cooling speed faster (from 280 ℃ to 50 ℃ in just 8 minutes), the efficiency is higher, and it can be stably controlled at room temperature of 5 ℃, expanding the application range of the instrument.

4.The instrument can be equipped with two packed column gasification chambers and one capillary gasification chamber simultaneously, as well as two capillary gasification chambers simultaneously, and can be expanded from a single amplifier to a dual amplifier. According to different analysis applications, different combinations can be used to install up to three detectors simultaneously, such as FID, TCD, ECD detectors, etc. Can easily achieve the series and parallel operation of detectors. Truly achieving one machine with multiple uses.

5.The instrument can be equipped with capillary columns of different specifications (caliber 0.2-0.53MM), and its reasonable capillary injection system design (with split/non split injection, diaphragm blowing, and tail blowing systems) makes the out of column effect small and the column efficiency high; To achieve a peak shape with high chromatographic peak height, narrow half peak, and no tailing, thus obtaining accurate and good repeatability quantitative results.

6.The instrument adopts unit modular design, making installation simple and maintenance more convenient; The new FID has a lower detection limit and can be easily disassembled and cleaned for the nozzle and ion collection electrode,The accurately fixed emitter installation structure ensures high consistency in the performance of each instrument.

7. The gas path adopts the method of stabilizing the pressure first and then stabilizing itDual flow design; Stable regulation mode, with high precision, high reliability, and convenient and intuitive flow regulation. Equipped with gas/air leakage protection and prompt function, it can automatically cut off TCD bridge current to protect rhenium tungsten wire from injury.

8. Equipped with a six channel temperature control system, including column chamber, gasification chamber, detection chamber, converter, and external control events.

9. It has a nine order linear program heating function, which can meet the analysis of multi-component samples.

10. It has power-off protection, over temperature protection, and power on self-test functions.