Variations in flow can cause peak broadening or tailing , affecting resolution and sensitivity . Using advanced flow control technologies such as electronic pressure control ( EPC ) in gas chromatographs and precision dosing in liquid chromatographs can maintain consistent flow rates . In addition , real-time monitoring and feedback systems can adjust parameters dynamically to ensure flow stability .
Temperature stability is equally important ; fluctuations can affect the viscosity of the mobile phase and the interaction between analytes and the stationary phase , leading to inconsistent retention times . By implementing precise temperature control systems , such as oven temperature programming or thermostat-controlled column compartments , these issues can be mitigated .
Durability and maintenance Increasing demand for highthroughput analysis and point-ofcare testing is driving the need for compact , automated chromatographic systems . Microfluidic technology as well as automated sample preparation and injection systems can reduce sample and reagent consumption , improve throughput , and enable portable applications .
Clearly , for equipment that is used regularly , a robust build quality and simple maintenance procedures are important . Frequent interventions for maintenance caused by system wear and tear can lead to downtime and increased operational costs . Developing durable materials and components , along with automated maintenance protocols , can enhance system longevity and reduce downtime .
The choice of valve can also have a significant effect on maintenance costs and process availability . In a laboratory with an eight-hour working day , valves clocked at 1 Hz , operating for six hours will perform 21,600 switching operations per day .
Using a conventional solution , the valve reaches 10 million operations and can be used for 463 days .
However , selecting a Bürkert solution that can achieve 100 million operations means the equipment can operate for 4,630 days . This equates to a potential saving of 90 million circuits , a service life of more than 4,100 days and seven hours less maintenance , resulting in a more productive solution .
Individual challenges There are also challenges within the individual fields of liquid chromatography . Analytical work can be affected by vague switching behaviour of the liquid control valves , which leads to imprecise mixing in the mobile phase , leading to an inaccurate gradient . The valves and their control blocks play a vital role in delivering accuracy and cleanliness to the process .
Increasing demand for high-throughput analysis and point-of-care testing is driving the need for compact , automated chromatographic systems .
The quality of valve blocks is determined by the design and manufacturing expertise that goes into the complex process of machining as well as the quality of the surface finish . Mass produced valve blocks may not have the optimum level of quality or the best design features for a particular application .
It is better to have a range of options for materials and valves to ensure the most effective design is achieved . For example , incorporating pulse valves enables solvent bottles to be changed during operation , saving time for operators . In the same design , cleaning processes can be automated and valve blocks designed to optimise this activity as well .
Compact reliability
A similar situation exists for gas chromatography as well . Designing and building analysis equipment for laboratories is a complex task , needing to combine a
compact footprint with precision , speed of analysis and reliability . As a manufacturer , sourcing all the various components to create a gas control solution , as well as configuring and installing them can be a painstaking process .
This can be made much simpler by engaging with an expert in the field , such as Bürkert , that has the expertise to design , specify , source , assemble and test all the required components . The result is a task-specific device , optimised for performance and reliability , that delivers stable measurement results with excellent repeatability .
Furthermore , the gas control system can be designed with simple integration interfaces to match both the mechanical and electronic / communication protocols . More complex systems can include multichannel mass flow controllers , bespoke manifolds and integrated control systems , all of which can be developed and supplied by specialists such as Bürkert .
Precision results
Chromatographs offer clinical and pharmaceutical laboratories the means to conduct vital research and development work . The precise control of gas and liquid flow in chromatography is paramount to obtaining reliable analytical results . Overcoming the challenges in developing new chromatographs requires a multifaceted approach , incorporating advanced technologies and innovative solutions .
By addressing these topics with the support of experts such as Bürkert , the pharmaceutical and clinical sectors can continue to rely on chromatography for critical analyses , ensuring the safety and efficacy of drugs as well as the accuracy of clinical diagnostics .
For further information , please visit www . burkert . co . uk
Issue 69 PECM 69