Procedure
- A stock solution (40 mg/ml) of standard machine oil was prepared in n-Hexane and sonicated for 10 minutes over an ultrasonic bath.
- A 20cm × 10cm HPTLC plate coated with silica gel 60 F 254 and alumina60 F 254 (E. Merck, Darmstadt, Germany) was used for analysis.
- The samples were applied at 10 mm from the base of HPTLC plate by means of a Camag (Switzerland) Linomat V sample applicator using a syringe (100µL, Hamilton, Bonaduz, Switzerland).
- As oil sample is mixture of different components, so major peak is considered for the study.
- A linear calibration curve was obtained on applying the increasing concentration of standard machine oil in the range (2-16 µg).
- HPTLC analysis was performed on a computerized densitometer scanner 3, controlled by WinCATS planar chromatography manager version 1.4.4. (CAMAG, Switzerland).
- Plate was developed to a distance of 80 mm, in a Camag twin-trough chamber with mobile phase [n-Hexane: Diethyl ether: MeOH:: 7:2:1.5 (v/v)].
- Plates were derivatized using 5% sulphuric acid solution in methanol.
- Plates were evaluated by densitometry at 450 nm with a Camag Scanner 3 for quantification.