Creport 5500 series Medical Pendant/ICU Pendant
according to different clinical demands,to configure with expert level caring
configuration,multi kinds of gas outlet and power socket can be choosed,its
modular assembly,to make the medical suitable to different environment
use,which is inevitable choice for operation theater and ICU room.
1.Anesthesia Pendant
Convenient for anesthesia environment
using,fully meet purify environment demands.
2.
Surgical
Pendant
Simply structure,simply operation,easy to move.
3.
Cavascope
Pendant
Plate number is choosable,height is
adjustable,fully meet clinical requirments.
4.
ICU
Pendant/Bridge Pendant
Wide-angle smooth rotation,Comprehensive cover
nursing area,its necessary bearing platform for ICU.
Medical Pendant,Surgical Pendant,Hospital Pendant,Cavascope Pendant Shandong Lewin Medical Equipment Co., Ltd. , https://www.lewinmed.com
The atmospheric pressure gas sample is injected and injected through the injection septum by a medical syringe (1 ml to 5 ml). It is simple and flexible, but there are samples backflushing and leakage when the defects are present, and the quantitative error is large, and the repeatability is generally above 2.5%. This is because the pre-column pressure is higher than the ambient atmospheric pressure and the sample gas will leak along the inner wall of the syringe. At this time, although it can be compensated by coating a high-temperature vacuum silicone grease on the inner wall of the tube to improve the airtightness, the adsorption effect of the silicone grease on the organic matter may occur, and the quantitative error is still large. If the volume is injected with a six-way valve, it is not only easy to operate, but also the result is accurate. Reproducibility can be less than 0.5% as long as the operation is reasonable and certain skills are mastered. It is easy to adjust even if the ambient temperature, pressure changes or different corrections. In addition, the six-way valve can also be used directly for high pressure gas injection.
. Analyze the working principle, structure and sample direct contact valve material that you are using to suit your analytical requirements;
. Since the air tightness of the valve is very different (0.1~0.6Mpa), can you ensure that there is no air leakage when you connect to your pneumatic system? Otherwise, it will not only affect the stability of the instrument, but also can not guarantee the reproducibility of the instrument injection. . Quantitative tube volume: As small as possible when the sensitivity meets the requirements, the maximum quantitative tube volume should be limited to 10% when the number of trays drops during the experiment. Otherwise, the injection volume is further increased, and only the peak width is increased without increasing the peak height, or the injection volume when the chromatographic peak width is substantially not broadened is the maximum quantitative tube volume. For packed columns, it is generally not more than 5 ml;
. At present, in order not to affect the liquid injection injection, the six-way valve is often connected in series at the inlet of the vaporization chamber. Obviously, this connection increases the dead space. When the analysis requirements are high, it is best to directly enter the column across the vaporization chamber or insert the six-way valve carrier gas outlet directly into the column head through the injection pad;
. At ambient temperature, when the sample components are likely to condense or contain traces of liquid gas, consider the temperature effects of the six-way valve (including the piping that is introduced into the instrument): a) place the valve in the column oven; b) separately temperature-controlled heating . Sample pretreatment problems: a) Prevent dust and mechanical particles from entering the valve to affect air tightness or normal operation; b) Avoid contamination of valves with high boiling impurities. Sampling method: In order to prevent possible contamination or interference of the gas components in the environment, it is best to use a large syringe needle to enter the dosing tube like a liquid injection. It is not easy to use a variety of hoses or plastic pipes to access this: a) the pipe itself is not pure; b) in principle, all pipes will have an osmotic effect, which is especially disadvantageous for trace analysis.
. Sampling tools: At present, metal coating air bags, large syringes or special gas cylinders are commonly used. Unless the requirements are extremely low, it is rarely used in the bladder, plastic bags, etc.;
. Quantify the air pressure of the sample in the tube: Since the gas content is directly related to the air pressure, in order to ensure the repeatability of each injection, the pressure of the quantitative tube should be balanced with the atmospheric pressure after sampling. According to experience, it can be balanced for 20~30 seconds after sampling. ;
. Flushing the volume of the sample tube: Due to the different concentrations of the gas sample being analyzed, in order to prevent the higher concentration from entering the lower concentration sample, the interference of the original high concentration gas in the tube is quantified. When sampling, it is required to flush the quantitative tube with a new sample gas. The flushing volume is not less than 5 times the quantitative volume according to experience. The actual impact can also be judged and selected by the reproducibility of the experimental peaks;
. When is the time after injection, is the six-way valve rotated back to the sampling position?
Depending on the analysis, such as: the volatility of the baseline after injection, the qualitative and quantitative repeatability is determined, according to experience, after the injection is a few seconds (when the first peak has not yet appeared), the valve is rotated back. The sampling position is better. At this time, it is easy to eliminate the poor airtightness of the valve and the excessive volume of the quantitative tube to affect the baseline or the peak;
. If the valve is found to be poorly airtight or contaminated, an experienced operator can remove the six-way valve. However, it should be noted that the sealing surfaces of the valve body and the valve disc are only allowed to be wiped with a soft cotton cloth, and the solvent is applied with volatile hexane. Acetone, chloroform, etc., after washing, dry with dry air. However, special attention should be paid to the use of halogen-containing hydrocarbons (eg, chloroform) as cleaning agents for gas six-way valve injection systems for ECD, which would otherwise be present at trace levels for extended periods of time. Strange peak
Six-way valve injection technology and skills in gas chromatography
In gas chromatography, injection is one of the main sources of quantitative analysis error. Because the principle, structure, materials used, temperature during injection, injection volume, injection speed, and tools for injection will have a direct impact on the qualitative and quantitative repeatability and accuracy of GC analysis. In the actual analysis, due to the different gas, liquid, solid and state of the sample, the analysis purpose is different, the requirements are different, and the sampling system for GC is various. For example, the atmospheric gas sample has a six-way valve gas injection or injection needle. There are two types of cartridge injection. Below we only summarize the gas injection six-way valve injection technology and skills for the reference of workers who often do gas analysis.