In the lab there is a long tradition of automation of sample preparation and often those systems are extremely complicated and expensive to introduce. However many labs do make the investment because it saves so much handling time and also eliminates human mistakes. In any case it allows scientist to spend more time with the instrumentation and interpretation of the data, and frees them up from that cumbersome extraction and often unhealthy solvent inhalation.
Today I want to highlight some of the major techniques we have for sample preparation for GC and GC-MS.
Robotic Sample Handling with TriPlus RSH Autosampler
We can automate the preparation of samples with building prep cycles; these are pre-written operations for the autosampler that go far beyond the normal injection modes of a sampler. The autosampler can be placed on top of one or indeed two GCs, but also for example as a standalone in the lab. Using prep cycles, the instrument can perform sample preparation procedures, like calibration curve building, dilutions or derivatizations in an unattended, reliable and fully automated fashion.
The Triplus RSH autosampler automates these cycles with the help of the Automatic Tool Changing Station (ATC), which can hold multiple syringes and automatically change them, as an example for switching from liquid to headspace to SPME analyses in the same sequence or simply to handle different liquid volumes.
A nice example is the application on automated derivatisation for analyzing melamine in milk with GC-MS/MS.
A completely automated analysis of biodiesel is a more widely spread application and thanks to the prep cycles we can handle in line extraction and injection, and analysis according to the legislative EN14105 and ASTM D6584.
Automated Sample Preparation with the AutoTrace
There are cases where, for example, in–vial extraction with the vortexing capacity of the RSH is not sufficient and more sample volume is needed to achieve the actual limits of detection required.
The Autotrace can handle from 20ml to 4L of sample, and perform automated SPE in aqueous samples. There are many applications available for you here.
One of the most prevalent applications with GC in the environmental lab is the analysis of TPH, or total hydrocarbons in water. This application typically is analyzed with GC-FID and it determines the mineral oil in water. The amount of peaks between C10 and C40 is a measure of pollution in environmental matrices and is used as an indicator for follow-up analysis for determining more and other semivolatiles. It is also used in many industries to determine the quality of the effluents or waste water; there are legal limits in place to protect the surroundings. The sample preparation can be automated completely.
And of course a complete and full methodology for the GC-FID can be found here.
Am I forgetting something? Yes, I sure am. I am forgetting to mention our solution for automated sample preparation with Accelerated Solvent Extraction for analyzing compounds in solid samples. If you do not mind, I am leaving that for another time.
But I do have a question for you all: What sample preparation do you want to automate in your lab? Let us know!