In recent years, in order to reduce the analysis time and improve the analysis flux, the ultra-high performance liquid chromatography technology has made remarkable development. Ultra high performance liquid chromatography instrument can withstand higher system pressure and flow rate, and the analysis speed and efficiency are greatly improved; The improvement of detector module and new data processing algorithm also effectively improve the rate of signal acquisition; With the development of modern chromatographic column technology, even a very short column length can provide sufficient high-efficiency chromatographic separation efficiency. For example, uHPLCs liquid chromatographic column has many lengths, such as 30, 50, 75, 100, 150, 200, 250 and 300mm.The high-efficiency separation technology is attributed to the liquid silica gel chromatographic filler. Through the advanced technology of uHPLCs, 99.9% ultra-high-purity spherical porous silica gel with extremely low metal content has unified management and quality assurance in pore size, pore volume, specific surface area, carbon content, metal ion content, peak symmetry, etc.
There are many research directions for liquid chromatography, among which improving flux is an important research direction to improve the analysis rate of liquid chromatography. In standard instrument operation mode, the automatic injector sequence occurs before each injection.This sequence usually includes moving the needle to the designated sample bottle location, sampling, moving back to the injector valve, and a series of needle cleaning to reduce sample residue. This approach has many limitations and operational steps that may increase instrument cycle time and thus reduce overall analytical flux.
Here we introduce the multiple injection technology. One change in the sample preparation of synchronous injection cycle is the multiple injection (miser) technology in a single experimental run. In miser, multiple injections operate in the same way as above, but the data is not collected as a separate chromatogram, but in a single data file.This is an ideal strategy for qualitative work, where a quick comparison of a series of runs in the injection sequence allows quick identification of general trends and outliers (i.e., high abundance and low abundance peaks) in the sample set.
The main disadvantage of MISER is the increased difficulty of peak quantization compared to collecting separate chromatograms for each unique run. Many software algorithms for quantification use area comparisons between analyte peaks and internal standard peaks at specific retention times (and/or m/z values, depending on the detection mode), which may be more difficult to combine on a single chromatogram when multiple separate separations have all been completed.Although it can still be done by liquid chromatogram resolution program or manual processing, these strategies require more user interaction to ensure that all peaks match correctly.
With the increase of running times in high-throughput screening experiments, the overall workload increases significantly. It is therefore important to consider the overall purpose of the ongoing high-throughput experiments, and more specifically whether they are qualitative or quantitative, to determine which approach is best suited to reducing cycle times.
Post time: Apr-12-2022
