Do you know how to deal with the common fault of the UHPLC operating?

At frist, we need to know what is UHPLC, Ultra-High Performance Liquid Chromatography, is a new category and new technology in chromatographic separation science.It has been optimized in terms of manufacturing technology, diffusion volume and withstand pressure. The solid phase of small particles is used to increase the throughput, sensitivity and chromatographic peak capacity of the analysis, and to maximize the chromatographic performance.

Chromatography instrument is a kind of precision instrument, and some incorrect operation or neglected experimental steps will lead to poor analysis effect of the instrument and even cause damage to the instrument. Among them, the most common problems with column pressure, drift, and abnormal peak shapes, such as ghost peaks, shoulder peaks, and peak tailing.

Fault 1: shoulder peaks

The packing status can change from exposure to long-term pressure loads or deterioration of the base packing material (dissolution of silica gel, for example). In many cases, a slight gap develops in the packing material at the column inlet, which can cause shoulder peaks or split peaks.

Fault 2: Ghost peaks

A ghost peak is a peak that appears at a position where we do not expect a peak”. It is a component that shows up in the system and it may show up everywhere in the chromatogram. Sometimes it is a sharp peak, sometimes it’s a broad peak or a “hump” and sometimes it is a rising baseline.

Fault 3：peak tailing

The primary cause of peak tailing is the occurrence of more than one mechanism of analyte retention. … Secondary analyte interactions, with ionised silanols on the silica surface, give rise to peak tailing. These interactions need to be minimised to achieve acceptable peak shapes.

It may also be due to the dead volume or extra-column volume being too large, the column efficiency is reduced, the column head collapses, etc., you can replace a suitable chromatographic column, or add a guard column in front of the chromatographic column.UHPLCS analytical/preparation guard column can trap the chemicals and particles that cause clogging of the chromatographic column sieve, column head collapse, and decrease in column efficiency.The filtration of sample and mobile phase can maintain the adsorption capacity of the guard column for chemical contaminants, and can maintain column efficiency for a longer period of time.