High performance liquid chromatography is an important branch of chromatography. Using liquid as mobile phase, single solvents with different polarities or mixed solvents and buffers with different proportions are pumped into the chromatographic column of stationary phase by high-pressure perfusion system. After the components in the column are separated, they enter the detector for detection, so as to realize the analysis of the sample.
High performance liquid chromatography has become an important application of separation and analysis technology in chemistry, medicine, industry, agriculture, commodity inspection and legal inspection. Divided into six categories:
1, adsorption chromatography
2. Partition chromatography
3. Ion chromatography
4. Gel filtration chromatography
5. Bonded phase chromatography
6. Affinity chromatography
Extended data:
Related terms:
1. Chromatogram: The signal-time curve obtained when the sample flows through the chromatographic column and detector, also called chromatographic outflow curve.
2. Baseline: After the mobile phase is washed and the chromatographic column and the mobile phase are balanced, the detector measures the outflow curve for a period of time. It should generally be parallel to the time axis.
3. Noise: baseline signal fluctuation. It is usually caused by poor power contact or instantaneous overload, unstable detector, bubbles in mobile phase or contaminated chromatographic column.
4. Drift: The baseline changes slowly with time. Mainly due to the instability of operating conditions such as voltage, temperature, mobile phase and flow rate, pollutants or stationary phase in the column will drift if elution is continued.
5. Chromatographic peak: the curve generated by the continuous signal response when the component flows through the detector. Projection on the outflow curve. The normal chromatographic peak is similar to the symmetric normal distribution curve (Gaussian gaussian curve). There are two kinds of asymmetric chromatographic peaks:
6. Leading peak and trailing peak. The former is rare.
7. Peak bottom: the distance from the starting point to the end point on the baseline.
8. Peak height (h): the distance from the highest point of the peak to the bottom of the peak.
9. Peak width (w): the distance between two tangents at inflection points on both sides of the peak and two intersections of the baseline. W=4σ
10, half-peak width (Wh/2): the peak width at half-peak height. Wh/2=2.355σ
1 1 peak area (a): the area surrounded by the peak and the peak bottom.
12, retention time (tR): the time when a component reaches the maximum concentration from the beginning of injection to the column.
13, theoretical plate number (n): used to quantitatively express the separation efficiency of chromatographic column (column efficiency for short).
14, resolution (r): the ratio of the retention time difference between two adjacent peaks to the average peak width. Also known as the degree of separation, it indicates the degree of separation between two adjacent peaks. R≥ 1.5 is called complete separation.
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