Evaporative Light Scattering Detector (ELSD) is a general-purpose detector. Although it has not been developed for a long time, it has been widely used in liquid chromatography for carbohydrates, lipids, fatty acids and amino acids, drugs and polymers. In the detection analysis. As the main factors affecting the detection effect of the evaporative light scattering detector, there are drift tube temperature, mobile phase composition and flow rate, carrier gas properties and flow rate. The effect of drift tube temperature on baseline levels and noise is not apparent. When the temperature rises, the mobile phase evaporation tends to be complete, and the signal-to-noise ratio increases. However, if the temperature is too high, the mobile phase will boil, which will increase the background noise, and at the same time may cause partial vaporization of the solute, which will make the signal smaller and reduce the signal-to-noise ratio. If the temperature is too low, the mobile phase is not fully evaporated and the baseline level is increased. Therefore, the optimum temperature should be based on the basic volatilization of the mobile phase (including the salt contained therein), and the lowest temperature at which acceptable noise is generated is the most desirable state. The better the volatility of the mobile phase, the higher the sensitivity of the method. The volatility, purity and concentration of mobile phase buffer salts will directly affect the baseline level, baseline drift and noise level of ELSD detection. The salt used as a buffer salt is required to be easily volatilized (generally thermally decomposed and volatilized) and has a high purity. Commonly used buffer salts consist of acetic acid, formic acid, trifluoroacetic acid, ammonium nitrate, diammonium hydrogen phosphate, and the like. Within a certain range, the lower the flow rate of the mobile phase of the liquid chromatograph, the lower the carrier gas flow rate required for the complete evaporation of the mobile phase, the larger the solute particles formed, the stronger the laser scattering ability, and the stronger the corresponding signal. When the carrier gas flow rate is too small, the mobile phase volatilizes incompletely, increasing background noise and reducing the signal-to-noise ratio. The optimum carrier gas flow rate should be the lowest flow rate at which the maximum detection response is generated based on acceptable noise.