Crude Oil Preparation

CHAPTER 2

LITERATURE REVIEW

2.1 Sample preparation method

Sample preparation is the most critical step in elemental analysis. Crude oil is a complex matrix of varying viscosities and mixed phases such as organic, water and particulate matter. Therefore crude oil is not an ideal matrix for analysis. The crude oil sample must be pretreated before analyzed by the instrument for metal analysis. This is the most important stage because errors might occur and is time consuming. The selection of a particular procedure depend several factors like analytical technique to be employed, nature and the number of the samples to be analyzed, desired degree of precision and accuracy required availability of the equipment, materials and reagents and the

In the oven cavity, there is a carousal (turntable or rotor) that can hold multiple extraction vessels. The carousal rotates 360º during extraction so that multiple samples can be processed simultaneously. The vessels and the caps are constructed of chemically inert and microwave transparent materials such as TFM (tetraflouromethoxyl polymer) or polyetherimide. The inner liners and cover are made of Teflon PFA (perfluoroalkoxy). The vessels can hold at least 200 psi of pressure. Under elevated pressures, the temperature in the vessel is higher than the solvent’s boiling point, and this enhances digestion efficiency. The vessels need to be cooled down and depressurized after

According to the principle of quantization of energy, very specific wavelengths of light emitted by hollow cathode lamp will transmitted through the sample of interest to determine the concentration of the desired analytes. Without the hollow cathode lamp, peak with narrow line spectrum due to the isolated wavelengths are difficult to obtain. Most commonly available types of lamp in market are hollow cathode lamps (HCL) and electrodeless discharge lamps (EDL).

2.5.1.4 Atomization

Rapid reaction occur reactions occur when the sample molecules enter into the flame. First, the water evaporation from metal complex takes place. Next, organic and dehydrated inorganic complexes degraded by the heat of into gaseous atomic states and then excited by the thermal energy in the flame. Besides, absorption of photons occurs by the electronic ground state gaseous

Atoms in the lower portion of the flame. Different elements require different flame conditions, including the choice of fuel and oxidant and the ratio of the fuel to oxidant mixtures. Hydrogen-air flames produce temperatures of about 2000 °C, while acetylene-air flames yield temperatures of approximately 2300 °C and acetylene-nitrous oxide yield temperatures of 2900