Srita

Waters ACQUITY UPLC System Enhanced Sample Management Capabilities
Since introducing the ACQUITY UPLC™ System in 2004, Waters has pursued programs to extend total system capabilities, and to furtheroptimize performance of this unique UPLC™ technology. The ACQUITY UPLC Sample Manager has benefited by providing more choices for needles, sample loops, and additional programming features. Among theenhancements contained in the newest software revision is a new injection mode, called “Partial Loop with Needle Overfill”. This technique is in addition to the Full Loop and Partial Loop – PressureAssist modes provided standard in all ACQUITY UPLC Systems. Waters continues to rigorously evaluate all injection modes with a wide range of conditions and sample types. Reproducibility, accuracy,linearity, and the other usual characteristics of autosamplers have been considered. Based on these tests and comparisons, the following “Best Practices” for sample injection on the ACQUITY UPLC™ systemare provided.

Selecting the Optimum Sample Injection Mode
The ACQUITY UPLC Sample Manager supports two injection modes – Full Loop and Partial Loop. For the partial loop mode, there are twoinjection techniques – Needle Overfill and Pressure Assist.

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Partial Loop with Needle Overfill

The Partial Loop with Needle Overfill is the best general purpose mode for partial loop injection. Itprovides the best partial loop accuracy, precision and linearity for a wide range of samples, including strong and weak acids and bases, hydrophilic, and hydrophobic compounds. It is recommended asthe first choice mode, except where there are clear indications for the others.

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Partial Loop – Pressure Assist

The Pressure Assist – Partial Loop mode should be reserved for those situationswhere analysis time takes precedence over any other concern, where the sample volume is very limited, or where the injection volume is very large.

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Full Loop – Pressure Assist

The Full...