IP 501 for Determination of Elements in residual Fuel Oil
IP 501 Determination of Aluminium, Silicon, Vanadium, Nickel, Iron, Sodium, Calcium, Zinc and Phosphorus in Residual Fuel Oil by Ashing, Fusion and Inductively Coupled Plasma Emission Spectrometry
5 Apparatus
5.1 General
The apparatus requirements are detailed in 5.2 to 5.16. All platinumware and glassware shall be sodium-free and carefully cleaned with hot hydrochloric acid solution (4.7.1) and rinsed thoroughly with water to eliminate contamination.

5.2 Inductively coupled plasma emission spectrometer
Use either a sequential or simultaneous spectrometer.

5.3 Platinum basin
Of 100 ml capacity with a minimum diameter of 70 mm. Clean the basin with fused potassium hydrogensulfate (4.2).

NOTE 1 - The following cleaning technique is recommended: place approximately 5 g of potassium hydrogensulfate (4.2) in the basin, heat in a muffle furnace at 550 °C±25 °C or over a Bunsen burner for 5 min. Allow to cool, wash out with water and dry.

5.4 Zirconium crucible Of a capacity of 30 ml to 50 ml, and fitted with a close-fitting zirconium lid.

5.5 Mixer
Non-aerating, high-speed type.

5.6 Oven
Electric, capable of being maintained at a temperature between 50 °C and 60 °C.

5.7 Muffle furnace
Electric, capable of being maintained at temperatures of 525 °C±25 °C and 925 °C±25 °C, and preferable having apertures at front and rear to allow passage of a slow, natural draught of air. Ensure that the refractory walls are in good condition, with no loose particles.

5.8 Hot plate
Electric, with or without a magnetic stirring capability

5.9 Volumetric flasks
100 ml and 1 000 ml capacity, complying with the requirements of ISO 1042, class A.

5.10 Pipettes
1 ml, 2 ml, 5 ml, 10 ml, 20 ml and 25 ml capacity, complying with the requirements of ISO 658, class A.

5.11 Pipettes
1 ml and 2 ml capacity, graduated in 0,1 ml subdivisions, complying with the requirements of ISO 835-2.

5.12 Measuring cylinders
10 ml, 25 ml, 50 ml and 100 ml capacity, with subdivided graduations, complying with the requirements of ISO 4788.

5.13 Beaker
400 ml capacity, squat form, complying with the requirements of ISO 3819.

5.14 Filter paper
'Ashless' grade, 0,01 % (m/m) ash content maximum.

5.15 Plastic bottles
100 ml and 1 000 ml capacity, suitable for long-term storage of dilute acid solutions.

5.16 Analytical balance
Capable of weighing to the nearest 0,2 mg.

6 Samples and sampling
6.1 Unless otherwise specified, laboratory samples shall be obtained by the procedures described in IP 475 or IP 476.

6.2 Thoroughly mix samples in their containers immediately prior to withdrawal of the test portions. Place the sample container in the oven (5.6) and maintain the sample at 50 °C to 60 °C until all the sample is fluid and of uniform viscosity. Insert the shaft of the mixer (5.5) into the sample container so that the head of the shaft is immersed to approximately 5 mm from the bottom of the container. Mix the sample for approximately 5 min.

NOTE 2 - Failure to use this homogenization procedure will invalidate results.