Sample application semiautomatic

Semiautomatic devices suited for preparative purposes are the CAMAG Linomat 5, the Desaga HPTLC applicator AS 30, and the Alltech TLC sample streaker. For all devices, the syringe has to be filled manually with sample solution and rinsed after sample application. Except for the Alltech TLC sample streaker, each of these instruments can be employed either as software-controlled or as a stand-alone device. The former is more convenient for creation, editing, and saving of the application pattern and instrument parameters. 

Figure 27. Semiautomatic sample application equipment Linomat IV (CAMAG)...

Striping equipment LINOMAT 5 semiautomatic sample application device from CAMAG (Wilmington, NC USA). 

In semiautomatic application of samples, the time factor is very important, as the operation should sometimes be performed as quickly as possible to prevent unstable materials from decomposing before the actual chromatography. Therefore, sometimes even an extension of the usual pause times, which are often fixed, can be necessary To give begirmers an idea of the time required for semiautomatic application with the Linomat IV, Table 7 gives some typical examples from our own experience, along with the equipment settings. 

The device delivers the kinetics not in single points but as a continuous exact curve. The continuous injection maintains a steady ligand concentration on the chip throughout the measuring time. Depending on the model, the application of the sample is automatic or at least semiautomatic and is evaluated by computer. In short, he is happy who measures with BIACORE. 

The first semiautomatic instrument utilizing all advantages of the spray-on technique was the (Lino-mat 5) (Figure 2). Today s latest model is software controlled. Only the y-position of the application is set manually and the user loads the sample into the... 

Sample preparation for each compound is performed in 96 well plate using a semiautomatic liquid handing station. LC-MS/MS instrumentation is used for the quantification of the sample and the final raw data are stored. Further calculation is done by appropriate quantification application. From the quantification, data concentration of unknowm samples are extrated and plotted versus the sampling time points (average plasma concentration vs. time). Pharmacokinetic calculations are performed by using pharmacokinetic software WinNonlin Pharsight Corporation) ... 

Although of limited value in qualitative analytical TLC, a variety of automatic or semiautomatic spot and streak applicators can be purchased. These applicators are used most frequently for quantitative TLC and HPTLC, and for preparative TLC. Jaenchen (1996) has reviewed instruments for application of samples for TLC and HPTLC. 

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