Method for detecting content of total nonvolatile matters in high-purity and ultra-pure ammonia

Abstract

The invention discloses a method for detecting content of total nonvolatile matters in high-purity and ultra-pure ammonia. The method comprises the following steps of: directly introducing ammonia into a volumetric flask and dissolving the ammonia in water, weighing a mass difference of the volumetric flask before and after the ammonia is dissolved, calculating the ammonia mass, slowly heating a ammonia water solution, releasing the ammonia through low-temperature evaporation, and then setting the heating temperature to be 100+ / 1 DEG C; pouring the ammonia water solution into an evaporating dish after the ammonia water solution is volatilized to a scale line of 100mL; heating the solution on an oven with the temperature of 100+ / 5 DEG C for 30 minutes after the ammonia water in the evaporating dish is totally evaporated; cooling in a dryer for 15 minutes; analyzing the scale weight and recording the reading; and finally, proportioning the mass difference of the ammonia water solution before and after the ammonia water solution is evaporated in the evaporating dish to the mass of the ammonia dissolved in the water, thus obtaining the content of total nonvolatile matters in the ammonia. The method has the advantages of being simple to sample, easy and convenient to operate, low in cost, high in analysis speed, high in detection precision, low in detection limit and short in analysis period.

Description

technical field [0001] The invention relates to a method for detecting impurities in gas, in particular to a method for detecting the content of total non-volatile substances in high-purity and ultra-pure ammonia. Background technique [0002] Electronic grade ultra-pure ammonia is a very important new optoelectronic material, and it is also an important basic material for GaN prepared by MOCVD technology. It is widely used in the manufacture of light-emitting diodes (LEDs), flat panel displays (FPDs), semiconductors and polysilicon solar cells. Especially during the growth of LED chips, ultra-high-purity ammonia gas is used in the epitaxial growth process of metal organic compound chemical vapor deposition (MOCVD). A chemical reaction occurs under high temperature and pressure to form gallium nitride: [0003] Ga(CH3)3(g)+NH3(g)→GaN(s)+3CH4(g) [0004] Therefore, the higher the purity of the ammonia used, the lower the power consumption of the prepared blue LED, the grea...

AI Technical Summary

Problems solved by technology

However, in the existing standards for ultra-pure ammonia in China, the monitoring method for total non-volatile substances is mentioned. It only proposes that ultra-pure ammonia should not contain visible solid particles, and does not clearly specify its indicators and corresponding detection methods.