Liquid handling is one of the most important (yet tedious) tasks in the analytical laboratory. However, analytical results are only accurate and reproducible when using the correct volume of sample, solvent, reagent, titrant, or auxiliary solution. With each manually prepared sample or solution, the risk for falsified results rises. This blog article discusses the many advantages of automating liquid handling steps.
The main concept of liquid handling is to transport a solution or reagent completely, accurately, and precisely from one place to another. Contrary to manipulating liquids with e.g., graduated cylinders, glass burets, or pipets, automated liquid handling utilizes piston-driven burets to perform this job.
A piston-driven buret from Metrohm consists of three major parts: the piston, cylinder, and dosing drive (Figure 1). Inside of the buret is a piston which is mounted in a cylinder. The piston is coupled to the spindle of a motorized dosing drive that moves the piston up and down within the cylinder.
Depending on the dosing device used, the drive can be mounted as shown in Figure 1 or turned by 180°. In the example shown here, liquid can be aspirated through the IN port when the piston goes down. Conversely, liquid is dosed through the OUT port when the piston goes up. A valve disk is used to switch between these ports.
Metrohm offers dosing devices that can handle either exchange, dosing, or cylinder units. Metrohm burets e.g., 807 Dosing Units, come in various sizes from 2 mL up to 50 mL (Figure 2).
Depending on the application, different materials are used to best suit the specific task. Glass cylinders (Figure 2) are used for general purpose liquid handling, while ETFE 807 Dosing Units (Figure 3) are used for more aggressive chemicals e.g., for dosing alkali reagents or hydrofluoric acid (HF).
Flexibility of control means that these burets can be used for various liquid handling tasks, e.g., the addition of titrants or auxiliary solutions, pipetting, diluting, sample preparation, and much more. This flexibility allows automated liquid handling to be used for many different applications like sample measurement, sample preparation, dilution, and standard addition for analysis techniques such as titration or ion chromatography (IC).
It is very useful to work with automated liquid handling devices in all kinds of industry sectors like pharmaceuticals, petrochemical refining, chemical manufacturing, environmental analysis, and more. Whenever an exact, known amount of a liquid must be used, automating this work is a must for the most accurate and dependable results.
Read our blog post to learn more about automated liquid handling solutions for the petrochemical industry.
Lab of the future: Automated robotic analysis of petroleum products
Automating liquid handling tasks can dramatically improve your daily lab routine. The following benefits are gained when manual liquid handling practices are automated.
Liquid handling tasks are completed more quickly or even completely automatically, allowing you to focus on other more demanding tasks. For example, an eluent can be mixed automatically at the touch of a button, or even an entire series of titrations can be processed overnight without the need for lab personnel.
Automation of liquid handling steps allows potentially hazardous or toxic substances to be handled more safely, as direct contact with these substances is minimized. The solution is added to a bottle to which a dosing device is attached. When the solution is required, the user only needs to press a button.
If you are still working manually with pipets, glass burets, and other kinds of measuring cylinders in your lab, it’s time to consider automation for your liquid handling processes. These days, electronic burets can do much more than just simply transfer a liquid from one place to another. Accurate, precise, cost-efficient liquid additions and sample preparation are only some of the benefits of switching to using automated liquid handling in the laboratory.
On-demand webinar: Automated liquid handling – The key to accurate and reproducible results
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