Flow meters and controllers for elemental analysis

When and why do traces of elements need to be measured?

Elements are measured for a wide variety of reasons. Environmental analyses are one example: high concentrations of heavy metals such as mercury, lead, cadmium and arsenic are dangerous to humans and the environment, so it’s important to monitor soil, plant and water quality. This is done using TEA techniques. In addition to such hazardous elements, even ‘ordinary’ elements such as carbon, hydrogen and sulphur need to be measured sometimes, as altered concentrations can be a sign of ongoing climate change.

I like that I can make a small contribution to a clean and safe world by enabling more data to be collected on pollution levels,
in combination with analysis devices manufactured by others.

More and more, I’m seeing pharmaceutical companies use these analysis techniques to analyze and safeguard the purity of their end products. But like I said earlier, there are many more potential applications, nearly all of which require precise and reproducible flow meters and controllers. That’s why we’re often asked to give recommendations and to help optimise the equipment used to measure trace elements. We look at the accuracy, reproducibility and speed of the analysis device and convert those needs into a suitable flow solution. Our extensive product range means we can offer solutions tailored to the specific requirements of any analysis device.

What is the specific function of a flow controller during analysis? 

First of all, the elements in the sample are separated from each other and then measured by a detector. Next, a carrier gas is used to transport the separated sample components. Other gases may also be necessary to bring about chemical and sometimes physical reactions, to make sure the elements to be measured are clearly identifiable. The carrier and reactant gases used must be pure, since the elements to be measured are only found in very small concentrations. The flow controllers and flow meters used to measure a carrier gas or administer a reactant gas must not only be highly accurate, but also extremely reproducible. In other words: the analysis results must not only be correct, they must also be exactly the same if you conduct the same analysis again the next day, or even somewhere on a mountain in Switzerland.

Can you tell us a bit more about these specific needs and requirements?

When it comes to flow meters and controllers, the needs of analysis device manufacturers often vary greatly. The shape of the instrument is important, of course, since it ultimately has to fit inside the device. Our customers also look at the signal processing method, the control system and the power supply. All of these are factors in deciding which instrument to use. Naturally, the price matters as well.

Because our own engineers and those of the customer work together as a team, they are capable of producing great results.

While Bronkhorst flow controllers are already capable of self-diagnosis to indicate the condition of the instrument itself, we’re also looking at how we can offer device maintenance predictions, e.g. by looking at the valve tension required to control the flow.

Right now, I'm busy looking at the various wishes and requirements of pharmaceutical companies when measuring trace elements – so I’d very much like to hear from readers who have thoughts on this matter!