Needle Caps for Liquid Injection Ports

Abstract

The invention discloses a needle-type sample injection cap used on a liquid injection mouth, which is characterized in that an outer pressing cap injection mouth is arranged on an outer pressing cap; an inner pressing cap injection mouth is arranged at the upper part of an inner pressing cap; a pressing cap blowing air drain is arranged inside the inner pressing cap, and two inner pressing cap blowing holes are formed inside the inner pressing cap; the outer pressing cap and the inner pressing cap are tightly matched, and the bottom edges are welded after assembly; a cap core hole is formed in the top end of a cap core; the upper thread of the cap core and the thread inside the inner pressing cap are tightly matched, and a seal gasket arranged therebetween is used for hermetically connecting the cap core and the inner pressing cap; the lower thread of the cap core is in fixed threaded connection with the connector of an elemental analyzer; a gas loading pipe (mouth), a cap core blowing pipe and a blowing gas port are arranged on the cap core; the outer pressing cap injection mouth, the inner pressing cap injection mouth and the cap core hole are concentric. The needle-type sample injection cap provided by the invention is skillful in structure manufacture, is convenient to replace, can effectively improve the value testing accuracy of key system parts, solves the problem of influence of air on analysis result during the liquid sample injection, and has excellent application and popularization value.

Description

technical field [0001] The invention relates to a special sample injection cap used for sample injection of all liquid injection port needle syringes. Background technique [0002] The study of stable isotopes of carbon, nitrogen, hydrogen, and oxygen in liquid samples is of great significance in indicating the source of water vapor, exploring the evolution of groundwater migration and the nitrogen cycle of living systems, and is widely used in earth science, environmental science, life science and other fields .In particular, it will play an important role in the research of global climate change, water resource assessment and management, carbon and nitrogen cycle of ecosystem, etc. [0003] The combination of elemental analyzer and gas isotope mass spectrometer has been widely used in the field of environmental ecological research in recent years. Among them, TCEA pyrolysis element analyzer can realize the test of water hydrogen and oxygen isotope ratio in water samples; ...

AI Technical Summary

Problems solved by technology

However, it was found during the test that since the injection port is exposed to the atmosphere, the moment the needle injector injects the sample from the injection port of the instrument, nitrogen, nitric oxide, nitrous oxide, carbon dioxide, etc. in the atmospheric components will enter the elemental analyzer. Affect the test and analysis effect of oxygen and nitrogen isotopes

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