Injection Valve is a device such as a rotary valve that allows the introduction of a sample solution in the HPLC column under high-pressure and flow conditions. An injection valve can be a standalone manual valve, or part of an autosampler . It typically consists of a needle port, a rotor and stator combination, and an exchangeable sample loop. A split-loop design includes the sampling needle as part of the sample loop, and aspires an exact sample aliquot to be introduced. A pulled-loop design aspires the sample by vacuum from an external sampling syringe into the loop. A pushed-loop design fills a loop with pressure.
The amount of the main component from the prior injected sample, which is observed in a subsequent injection of the sample diluent (blank) without analyte. Carryover performance is highly analyte-dependent, and is particularly problematic for very basic compounds and proteins. Precision reflects the variation (scatter) of the delivered sample volumes during repetitive injections as a relative standard deviation (RSD) of peak area or peak height.
Autosampler is a device that automates the introduction of an aliquot of sample solution to the HPLC column. An HPLC autosampler typically comprises a sample storage compartment with an injector, containing a valve, a sample dosing or metering device, and a moving sampling needle. A common issue with autosamplers is leaks. Problems such as usage of the incorrect needle or blockage of the waste line can cause samples and waste leaking from the autosampler. Uncontained leaks may expose the operator to hazardous materials without their knowledge. Autosamplers are available that can detect leaks and handle them safely, keeping the users safe. This is done by siphoning leaks into a single tray and triggering an alarm when the instrument detects liquid in the tray.
Autosamplers replace manual sampling and injection by automatically selecting a sample and inserting it into the inlets of the instrument. In addition to liberating the operator’s time, autosamplers eliminate sources of error and provide better reproducibility and accuracy, especially when working with very low volumes. Autosamplers are available for GC applications, such as liquid injection, static and dynamic headspace, SPME, and purge and trap, and for HPLC applications, including liquid injection, sample prep, and fraction extraction. They are used in medical and forensic labs and in the environmental, pharmaceutical, and food industries.
Autosamplers come with comprehensive maintenance schedules and instructions. By following the instructions and timeline for your instrument, lab members can perform weekly, monthly, and annual maintenance without a provider. This will help your lab save money on a service plan. Service providers can be contacted for more complex issues or if you are not comfortable replacing parts on the instrument.
An autosampler, which is short for automatic sampler, is a device used in analytical laboratories to automatically and reproducibly deliver a sample to an analytical instrument in which the sample is to be analyzed. Autosamplers can be used in chemical along with medical laboratories. This article mainly concentrated on the use in chemical analysis labs. Autosamplers are commonly coupled to analytical devices to quickly and accurately load samples for analysis. Autosamplers can be equipped to perform simple liquid, solid, headspace, or solid phase micro extraction (SPME) injections.
