This Technical Note describes the configuration and operating principles of the Agilent 1100 Series dual-loop autosampler, as well as the different injection modes – complete and partial loop fill. Parameters influencing the quality of the injection are shown for both injection methods. Carry over is discussed and different wash and rinse features are explained to keep the carry over as low as possible. This application has been verified using an Agilent 1200 Series LC system, and showed comparable or even better performance.
The document details the Agilent 1100 Series dual-loop autosampler (DLA), which utilizes a unique fixed loop injection principle involving a buffer loop and a sample loop. This design allows for two distinct modes of operation: complete loop fill, ideal for high-precision analytical tasks, and partial loop fill, suitable for preparative work where minimizing sample waste is critical.
The text analyzes performance factors such as overfill factors for complete filling and draw/eject speeds for partial filling to ensure accuracy. It also discusses carry-over reduction strategies, including needle washing and valve rinsing features designed to maintain low contamination levels between injections.
To ensure the entire sample is applied to the column, you should not inject more than 50% of the sample loop volume.
For the best area precision and injection quality, you should fill the sample loop with between 10% and 50% of its volume.
To achieve highest accuracy and precision, you must use an overfill factor of at least 3 to 5.