>> Update My Profile | Subscribe to Access Agilent | Article Directory

More speed and sensitivity for impurity analysis with the new Agilent 1290 Infinity LC System

By Christian Gotenfels, Agilent Product Manager, Liquid Chromatography;
Dr. Gerd Vanhoenacker and Prof. Dr. Pat Sandra, Research Institute for Chromatography

Many pharmaceutical labs face an overwhelming sample load and need to increase throughput and productivity while reducing costs. In response, some labs are trying to develop LC methods that are four to five times faster than those used today. The challenge is to dramatically increase speed without compromising the accuracy, precision, and repeatability of the method. The Agilent 1290 Infinity LC System helps to achieve this goal by providing an extended flow and pressure range and new levels of sensitivity.

Figure 1. The new design of the 1290 Infinity DAD maximizes signal while reducing noise and baseline drift, so you detect impurities at lower levels. (Click here to see this image larger.)

In liquid chromatography (LC), you can speed up analyses by using particles that are smaller than 2 µm and/or by operating at elevated temperature. Columns packed with sub-2-µm particles allow you to significantly increase mobile phase velocity, but you do need specialized LC instrumentation. A number of vendors offer dedicated instruments for fast LC, but all of them operate at different pressures, flow rates, system volumes, temperatures, and detector sensitivities. So each system suffers from performance limitations for specific column dimensions or particle technologies.

No more compromises in LC performance

The new Agilent 1290 Infinity LC System overcomes these limitations. It offers the widest available power range, combining ultra-high pressures up to 1200 bar and high flow rates up to 5 mL/min. This flexibility allows you to choose the column dimension, particle type, mobile and stationary phase, flow rate, and pressure that provide optimum separation and speed. And you can now more easily detect low-level impurities. The innovative optical design of the Agilent 1290 Infinity Diode Array Detector (DAD) – featuring Agilent Max-Light flow cells with optofluidic waveguides – delivers highest UV sensitivity and baseline robustness.

Figure 2. The initial analysis on the conventional Agilent 1200 Series LC system took 14 minutes. The chromatogram shows the sample formulation spiked at the 0.5% level with impurities 1 to 9. (Click here to see this image larger.)

Figure 3. The analysis on the 1290 Infinity LC took only 3.2 minutes, which was four times faster than the original method. (Click here to see this image larger.)

Four times the speed, without loss of resolution

To show how you can gain both speed and sensitivity, we transferred the LC impurity analysis of metoclopramide hydrochloride formulations from an Agilent 1200 Series LC system (Figure 2) to a 1290 Infinity LC. The method transfer was straightforward once we considered some instrumental characteristics, such as the significantly lower delay volume of the 1290 Infinity LC. After the initial transfer, we changed the original column (150 mm x 3.0 mm, 3.5 µm particle size) to a narrow-bore 2.1 mm column with smaller 1.7 µm particles.

The new column significantly improved the resolution between the compounds. The use of particles smaller than 2 µm allowed us to increase the mobile phase velocity to reduce the analysis time without hampering resolution. The high pressure and mobile phase velocity generated frictional heat, which changed the selectivity of the method, so we lowered the column temperature to maintain the original selectivity. The final analysis on the Agilent 1290 Infinity LC System used a 100 mm column at 880 bar and was four times faster than the original HPLC method (Figure 3).

Validated method far exceeded sensitivity requirements

We successfully demonstrated the linearity, injection repeatability, and detection limits of the revised method on the Agilent 1290 Infinity LC System, using the conditions shown in the table that accompanies Figure 3. The limits of detection varied between 0.001 and 0.005% by weight relative to the main compound. This corresponds to 50 to 250 pg on-column, which is 10 to 50 times lower than the required reporting level.

The 1290 Infinity LC delivers new levels of sensitivity and all the flexibility you need to successfully translate your conventional LC methods to fast LC. If you want to solve your sample throughput problems and achieve greater sensitivity at the same time, learn more about the Agilent 1290 Infinity LC System. And for all the details about the successful conversion of the metoclopramide hydrochloride method to a fast LC method, download Agilent Application Note 5990-3981EN.

>> Update My Profile | Subscribe to Access Agilent | Article Directory