CAMAG Linomat

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 5.12 Close-up view of the spray nozzle (CAMAG Linomat 5). 

Fig. 2 Camag linomat IV band applicator. (Photo courtesy of Camag Scientific, Inc.)...

To prevent oxidation of substances on the layer, protective measures must be taken even before the samples are applied. Using the CAMAG Linomat IV with inert gas blanket, nitrogen (for example) can be applied before and during application of the sample. To develop thin-layer chromatograms with exclusion of O2, the chamber is purged with CO2 if the substances are not affected by this gas, or alternatively with N2. For this, a lid fitted with a tube with a double-valve gas supply system is useful [20, p.69]. 

Nitrocellulose Hi-flow plus membrane was cut into sections (3.0 x 0.5 cm2), for the detection of small molecular (such as pesticide). The procedures of preparation of membrane strip were shown Step 1 The membrane was coated with hapten-OVA conjugates in a volume of 1 a.L containing 1 pg hapten conjugate as test line with Camag Linomat 5 automatic TLC sampler. The control line was coated with 0.5 pL of anti-rabbit IgG from goat diluted 1/100 in PBS buffer (pH 7.2). The distance between the two lines was 0.5 cm. 

Figure 5.3 shows the microprocessor-controlled Camag Linomat IV, which applies samples in the form of narrow bands by a spray-on technique in which nitrogen carrier gas atomizes the sample from a syringe onto the plate, which is moving back and forth under the atomizer. Band length is selectable between 0 ( = spot) and 190 mm. Although sample volumes of 1-100 (xl can be applied by the Linomat, the sample size most used is 5-20 pi for TLC and HPTLC plates. 

Figure 5.3 Camag Linomat IV. (Photograph courtesy of Camag.

Samples for preparative layer chromatography are applied as bands across thicker layers. This can be done manually by allowing sample to flow from a pipet drawn along the edge of a ruler. The Camag Linomat, described above, is among the special instruments designed to apply samples more uniformly. 

Thus, a complex mixture is first separated with a microbore system, thereby providing a low flow rate of about 60 llLVmin. This low flow rate enables a connection without a splitter by transferring the selected HPLC fractions directly to the TLC plate with the aid of a special application device (CAMAG Linomat C or ATS III). The coupling of a reversed phase HPLC system with a normal phase TLC system is leading to an enormously efficient method. 

CAMAG Linomat IV Mobile stage with fixed turret. Speed 10 mm/sec Volume 5 to 10 sec/pl Width of band 0 to 190 mm... 

CAMAG Linomat IV (Figure 17) Microprocessor controlled bandwise applicator which optimizes conditions for subsequent densitometric measurement. It has a range of 5-490 pi for preparative separations and 1-99 pi for quantitative application. 

CAMAG Linomat C Microprocessor controlled spray application of effluent from HPLC onto HPTLC plates. Column flow rates of up to 1(X) pl/min can be used. 

Samples (30 and 20 /xl) were applied as 4 mm bands by means of a Camag Linomat 5 device. Development was performed in an unsaturated chamber (20 x 20 cm twin-trough) to a distance of 10 cm. 

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