Things you can do with a MultiFlex (No.4) – Liquid Handling

Kathy Ridgway

5th December 2013

A Dual Head MPS can bring the benefits of auto spiking to any laboratory

Addition of Internal Standards

When working with samples, even those needing no sample preparation, there are always some basic liquid handling tasks that have to be done. This is why the MultiFlex is equipped with two syringe heads – one for the injection of samples and one for liquid handling.

At the very least, virtually every sample will need the addition of an internal standard.

An increasing number of laboratories have come to the realisation that the spiking of internal standards into samples is something that humans are inherently bad at.

Some time ago, we performed a study in our application laboratory, using gravimetric measurements, that showed that the GESRTEL MPS can easily match the precision of “grade A” glassware, when it comes to liquid handling.

Work carried out when we were developing MPS auto spiking on our VOC Analyser, showed that the precision obtained was as good as the most careful analyst could achieve. What is more, the MPS never made mistakes, so no samples were ever double-spiked and no samples were ever missed.

Simon McInulty, one of Anatune’s service engineers, worked in a high throughput lab when auto spiking using a GERSTEL MPS was implemented:

“The biggest difference it made to us was to cut the number of “re-runs”. Before, anything up to 15% of samples had to be repeated due to spiking errors. When we brought in auto spiking the number of re-runs dropped to 2% or so. That saved a lot of messing around”.

The time saving can be considerable. Some labs run hundreds of samples a day, and for them adding internal standards to samples can occupy several members of staff full-time. In these circumstances, the return on investment is ridiculously quick (a few months at most) and the positive impact on laboratory productivity, immediate.

Even for analysts running smaller batches of samples, the time savings are significant and the elimination of human error is very welcome.

In some cases, you can conveniently perform this neat trick with the same syringe that you use for injection (in which case you get all the advantages for free). However, the addition of a second injection head and syringe carriage adds little to the cost of a system and gives you much greater flexibility in the volumes of liquid you can work with.

With only a little more thought effort, you can get the system to make-up standard solutions for you. When you need to build a multi-level calibration curve, you can set-up the MPS to prep your standards. The instrument will prepare the samples the exact same way every time and, once again, you reduce the chance of human error spoiling your day.

This is why, just about every system our customers now buy, is bought with a dual head MPS.

For more information, email, or call the office now on 01223 279210.