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ACQUITY UPLC I-Class System: Optimized System Diffusion, Optimized UPLC Performance
purpose
To ensure that the ACQUITY UPLC ® I-Class system minimizes the extra-column band extension, the separation is better with high resolution and high throughput UPLC ® separations. The importance of these improvements will be illustrated below by impurity analysis and ballistic gradients.
background
It has been demonstrated that in a variety of applications, the column packed with sub-2-n particles can improve peak capacity and resolution of chromatographic separations, thereby greatly increasing resolution and throughput.
However, in order to maximize the resolution that can be achieved with a given separation, it is necessary to minimize system diffusivity. Any liquid line or connection that is part of the system flow path after the injector can cause extra-column band broadening. Includes injection valve, solvent preheater, connecting lines, fittings, and optical flow cell. Many suppliers have tried to improve the spread of UHPLC systems, but with little success. Although the diffusibility can be reduced, it is still not optimal to obtain all the advantages of a narrow-bore UPLC column (inner diameter 2.1 mm). These columns require a lower flow rate, which results in a higher return on investment for each sample, allowing for efficient separation with sufficient resolution.
solution
The ACQUITY UPLC I-Class system reduces the extra-column band distribution. The optical path of the newly designed UV detector flow cell is the same as the optical path of the previous ACQUITY UPLC, providing the same high sensitivity; in addition, the fluid lines and connections have been redesigned to further reduce band spread. Solvent preheaters must be used to minimize temperature gradients that can cause dispersion effects on the column. Therefore, the volume of the solvent preheater should be small enough to ensure that the sample plug reaches the head of the column with minimal diffusion and provides excellent solvent heating performance even at high temperatures and high flow rates. Depending on the needs of your lab, you can choose one of two sample managers to form the ACQUITYUPLC I-Class system. Whether using a fixed loop (SM-FL) or a flow-through needle (SM-FTN) injector, it has been caused by a small volume of needle ports, connecting lines, and internal valve passages. The diffusivity is minimized. Typically, the design of the fixed loop injector allows the extra-column band to be expanded to a lesser extent because it reduces the volume of the syringe flow path. By optimizing each component, the extra-column band spread has been significantly reduced compared to any other commercially available LC system. Table 1 summarizes the band extension values ​​obtained after using a variety of systems, including UHPLC systems.
The ACQUITY UPLC family outperforms all other systems in maintaining the integrity of ultra-efficient separations, among which ACQUITY
The band spread of the UPLC H-Class system is reduced to 9 _L, while the ACQUITY UPLC I-Class system is reduced to as low as 5.5 _L.
Reduced system diffusivity can directly lead to increased resolution of the ACQUITY UPLCI-Class system. Separation can achieve a ballistic gradient while maintaining the resolution in a typical analytical gradient. Figure 2 illustrates the results of impurity analysis for tetracaine.
Separation under the same conditions using the ACQUITY UPLC I-Class system and the UHPLC system from Supplier B.
The separation of the ACQUITY UPLC I-Class is significantly better. Supplier B's system installed a flow cell with an optical path length of 60 mm as recommended, and found that it produced significant band expansion so that no shoulders were detected.
summary
The ACQUITY UPLC I-Class system delivers unmatched performance for today's most challenging separation tasks. Whether your lab needs to increase separation during separation or increase sample throughput, its flexible system configuration minimizes the extra-column band spread on UPLC columns for optimal separation performance.
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