Layers a Cellulose MN

Cellulose MN 300 powder (15 g) is homogenized in a blender with distilled water (90 ml) for 30 sec [3]. The suspension is spread onto the plate to a thickness of 250 [x with the Desaga apparatus and the moist plate is dried at 100° for 10 min. The addition of calcium sulphate or other 

The microcrystalline cellulose ( Avirin or AviceF , 100 g) is blended in a mixer for 15—45 sec with distilled water (430 ml). The amount of water required may vary with the particular lot of cellulose. An insufficient amount of water results in cracking of the layer. The cellulose suspension is transferred to a filter fiask and placed under vacuum for a few min to remove air bubbles. The plates are spread by means of a Desaga apparatus (Firm 44) (drawn slowly) to a thickness of 1.0 mm and dried overnight at room temperature or at 80° for 30—60 min. Thin layers (250 [x) are not as suitable for either analytical or preparative work. The performance of the plates is also infiuenced by the time of blending and for good smooth plates the mixture should peak somewhat. 

Cellulose layers are very durable and the plates may be stacked together for storage or written on without crumbling. They need not be desiccated. 

A suspension of sieved ECTEOLA-cellulose powder (Firm 127) (2 g) in 0.004 M ethylenediaminetetraacetic acid, pH 7.0 (18 ml) is shaken vigorously for 5 min. The slurry is spread uniformly on a glass plate (20 X 20 cm) and dried overnight at room temperature giving a layer about 200 [X thick. The dried layer is then sprayed with 0.1 M ammonium tetraborate, pH 9.0, hnd dried at 50° for 30 min. No changes are found on storing the plates for 3 days. 

Calcium suKate hemihydrate (0.8 g) is ground for 1 min in a mortar with distilled water (5 ml). The Cehte adsorbent (Filter Cel or Hyflo Super-Cel) (15 g) and additional water (60 ml) are added and the mixture is ground for 1—2 min. The smooth slurry is spread with an applicator in the usual way to give five 8 x 8 in (20 x 20 cm) plates which are air-dried for 10—15 min and then dried at 100° for 30 min. 

---