Next level sample preparation
The new AOC-6000 autosampler
The new AOC-6000 autosampler
For more than a decade, the AOC-5000 autosampler has been state-of-the-art for various injection techniques and is still today a reliable sampler for daily laboratory routine. However, in recent years the specifications of many laboratories have increased significantly – from simple sample preparation with subsequent injection to complex automated processes. Automated systems make sample preparation and analysis results more reliable as they eliminate the influence of ‘human error’. At the same time, efficiency is increased and costs are minimized.
With the AOC-6000, an autosampler is now available that not only meets these needs, but also sets standards in integrated sample preparation.
The development of the AOC-6000 focused on extension of its application range. The automated syringe exchanger unit (figure 1) plays a central role here. While the AOC-5000 was limited to the use of one syringe during operation, the AOC-6000 can handle up to six different syringes during ongoing operation – syringes for liquids (1 – 10,000 µL), headspace syringes (1 – 5 mL) or SPME fibres.
Figure 1: Syringe exchanger unit
In addition, other minor modifications were implemented that extend the possibilities of the AOC-6000. The ‘Fast Injection Mode’ allows for non-discriminating injection of hydrocarbons up to a chain length of C40. A small contact sensor in the injection head enables the detection of the vial bottom so that even the smallest amounts of sample can be used. With 5 µL of sample, it is possible to inject 3 x 1 µL accurately from this sample. A vortex mixer (figure 2) enables thorough mixing of different solvents and reagents. Vials in sizes of 2 mL, 10 mL or 20 mL can be agitated at up to 2,000 rpm.
Figure 2: Vortex mixer
One of the new application areas results from combination of the AOC-6000 with the high-end GCMS-TQ8040 or GCMS-QP2010 Ultra instruments (figure 3). Through the patented design of the high-vacuum range of these systems, two chromatographic separation columns can be operated simultaneously without any loss in sensitivity and with no cross contamination. This creates the possibility for fully automated injection of various types of samples onto the most suitable chromatographic separation column with subsequent ultra-high sensitivity analysis. In this way, for example, a liquid sample can first be injected onto a non-polar separation column while the headspace sample is being prepared simultaneously in the incubator. When the sample preparation is completed, a portion of the headspace can be injected directly onto the second polar column in the next step.
Figure 3: Combination of the GCMS-TQ8040 and the AOC-6000
Complex sample preparation made easy
The AOC-6000 reaches its greatest potential in complex sample preparation. This usually involves the combination of very different steps, the use of strongly differing volumes and the mixing of highly reactive compounds. Some examples of complex preparations are the addition of an internal standard, the creation of a calibration curve or the derivatization of substances that are difficult to analyze using gas chromatography without chemical conversion. For these basic tasks, the AOC-6000 offers ready to use methods that can be implemented easily in the daily laboratory routine, enabling easy access to automated sample preparation.
A very time-intensive and error-prone routine task in the laboratory is the creation of a dilution series. When using the AOC-6000, it is sufficient to load the autosampler with chemicals and vials as well as to parametrize the preconfigured basic method. Fully automated preparation as well as subsequent injection into the GCMS then takes place. Figure 4 shows a calibration curve created with the aid of the AOC-6000, while figure 5 shows the corresponding stepwise approach.
Figure 4: Calibration curve created using the AOC-6000
Figure 5: The stepwise process for the creation of a calibration curve using the AOC-6000
The possibilities of the autosampler are, however, not limited to these basic tasks. Every analytical laboratory has its own specific know-how and requirements, which must be taken into account during automation of sample preparation. To integrate this unique knowledge into the sample preparation process in an optimum way, it is possible to develop customized methods in close cooperation with experienced Shimadzu engineers and to integrate these methods in daily laboratory practice.
Smart software control
Especially important for a simple and efficient use of an autosampler is the way the control software is integrated in the chromatographic data acquisition system. Typically, autosamplers are controlled via a second software, which can lead to synchronization problems between autosampler and chromatograph. This is not the case with the AOC-6000, which is fully integrated in the tried and tested GCMSsolution software. All parameters needed for sample preparation and measurement are entered into the software and can be viewed very easily and afterwards verified.
Figure 6 shows a screenshot of the GCMSsolution software. Each of a total of six preconfigured methods is divided into three parameter groups. In this way, the user can easily select the basic parameters (setup + analysis) of a method. If special parameters requiring an increased level of knowledge on the injection technique need to be adapted, this can be carried out via the advanced section.
Figure 6: The control software GCMSsolution for sample preparation and injection
With this high degree of flexibility and easy handling, the AOC-6000 sets new standards for integrated sample preparation, and offers both routine and advanced users a broad application spectrum.