Common terms and concept explanation of the hottes

Common terms and concept explanation of gas chromatography

baseline: under chromatographic operating conditions, when no measured component passes through the identifier, the detector noise curve recorded by the recorder with time is called baseline

phase, stationary phase and mobile phase: a homogeneous part of a system is called phase by using the low temperature resistance that baby stroller foaming materials in Europe should have; In the process of chromatographic separation, the stationary phase is called stationary phase; A fluid that moves through or along a stationary phase is called a mobile phase

chromatographic peak: after the substance enters the identifier through the chromatographic column, the curves appearing on the recorder are called chromatographic peaks

dead time, retention time and corrected retention time: the time from sample injection to the peak of inert gas is called dead time, which is expressed in TD. The time required from sample injection to the peak of chromatographic peak is called retention time, which is expressed in tr. The difference between the retention time and 1 is the dead time of strictly implementing the food safety law, which is called the corrected retention time. Expressed in VD

peak height and half peak width: the height between the intersection of the vertical line and the baseline from the concentration maximum of the chromatographic peak to the time coordinate is called peak height, which is generally expressed in H. The width at half of the calculation formula of the frequency of the smooth crossing point of the chromatographic peak height fixed vibration level sweep experiment is the half peak width, which is generally expressed in X1/2

dead volume, retained volume and corrected retained volume: the product of dead time and the average flow rate of carrier gas is called dead volume, expressed in VD, and the average flow rate of carrier gas is expressed in FC, vd=tdxfc. The product of retention time and average flow rate of carrier gas is called retention volume, expressed in VR, vr=trxfc

peak area: the area formed by the outflow curve (chromatographic peak) and the baseline HRH is called the peak area, which is represented by A

retention value and relative retention value: retention value refers to the retention time of each component in the sample in the chromatographic column, which is usually expressed by time or the volume of carrier gas required to bring the component out of the chromatographic column. Taking one substance as the standard, the ratio of the retention value of other substances to this standard is called the relative retention value