Description of Accredited Methods
1. Density by the areometric method in accordance with PN-EN ISO 3675 standard.
The tested sample is brought to a certain temperature. Next, its one part, as the analytical sample, is transferred to a hydrometric measurement cylinder. The cylinder is brought to approximately the same temperature as the sample. A properly selected aerometer with a temperature close to the temperature of the sample is immersed in the tested sample and allows free positioning. After temperature equalizing, the hydrometer parameters data are read. The tested sample temperature is recorded and the corresponding density value at 15 ° C is read with the help of standardized conversion tables.
If necessary, the areometric measurements cylinder and its contents are placed in a bath at a constant temperature, which avoids temperature fluctuations during the measurement.
Range: 600-1000 kg / m3
2. Density by the oscillatory method in accordance with PN-EN ISO 12185, ASTM D 4052 standard.
Density is the basic physical quantity. It is used in conjunction with other quantities to characterize both light and heavy fractions of crude oil and petroleum products. A small volume (usually less than 1 ml) of the test sample is introduced into a temperature-controlled U-tube. The vibration frequency and the density of the test sample are measured by applying the measurement constant determined, which is appointed by measuring the U-tube frequency vibration filled with a reference material of known density.
Range: 700-900 kg / m3
3. Fractional composition by the distillation method in accordance with PN-EN ISO 3405:2012, ASTM D86-12 standard.
The fractional composition, which is determined by normal distillation, is characterized the fuel ability to pass into steam and is a fuel volatility parameter. The sample, due to its composition and predicted volatility characteristic, is assigned to one of the four groups. The classification is based on an apparatus assembly defined method, condenser temperature and operational variables. The analytical sample of 100 ml volume is distilled under specific conditions. The conditions depend on the group to which the sample was assigned. Then, the thermometer and the volume of condensate obtained are systematically observed. The residue in the flask volume is measured and the loss from distillation is recorded. The thermometer’s readings for atmospheric pressure are corrected and the data obtained is used in calculations according to the sample nature and the specification requirements.
Range: 0-400 ° C
4. Ignition temperature by the “Pensky-Martens” method (the closed-cup methode) in accordance with PN-EN ISO 2719:2007 standard.
The test sample is placed in the crucible for the Pensky-Martens apparatus. While constant stirring, the sample is heated to provide the continuous temperature increase. For parameter determination, the ignition source is introduced through a hole in the crucible cover at regular temperature intervals with simultaneous interruption of mixing. The lowest temperature at which application of the ignition source will ignite the sample vapours and the flame spreading above the liquid surface is recorded as the flash point at ambient atmospheric pressure. This temperature is corrected to normal atmospheric pressure by using the appropriate equation.
Range 40-150 ° C
5. Ash content by the weight method in accordance with PN-EN ISO 6245:2008 standard.
The parameter is introduced to protect product against possible components that may form ash. The residue after incineration is determined by the method of burning the sample in a special vessel, reducing the carbon residue to ash by heating it in the oven at 775 ° C and weighing the obtained residue.
Range: 0.001-0.020% (m / m)
6. Cloud point temperature by the manual method in accordance with PN-ISO 3015:1997 standard.
The test sample is cooled at a determined rate and periodically checked for appearance. The temperature at which turbidity appears at the tested tube bottom is taken as the cloud point.
Range (-35) -35 ° C
7. Copper-corrosive action by the visual method in accordance with PN-EN ISO 2160:2004. ASTM D 130-12 standard.
The method is used for testing the corrosive action on copper liquid petroleum products and specified solvents with a maximum vapour pressure of 124 kPa at 37.8 ° C. A polished copper plate is immersed in the sample of a specified volume. Then it is heated at a specified time and temperature, which are determined for the particular product. Air fuel and raw gasoline are tested in a pressure vessel, while other products are tested at atmospheric pressure. At the end of the heating period, the plate is removed and washed. The colour assessed by comparison with corrosion standards.
8. Kinematic and dynamic viscosity by the capillary method in accordance with PN-EN ISO 3104:2004 standard.
The determination of liquid viscosities by measuring the time of flow of a given volume liquid under the influence of gravity. The test is performed under reproducible and controlled conditions. The kinematic viscosity is calculated by multiplying the flow time by viscometer constant.
Range 1,600-6,000 mm2 / s
9. Determination of the contamination content by weighing method in accordance with PN-EN 12662:2014-05 standard.
Contamination is understood as the insoluble substances which are retained on the filter membrane after filtration under the test conditions. The part of the sample is weighed and vacuum filtered through a pre-weighed membrane filter. The filter with the residue is washed, dried and weighed. The contamination content is calculated on the basis of the difference in the filters mass and is determined in relation to the mass of the sample in mg/kg.
Range: 6-30 mg / kg
10. Determination of the water content of clear and transparent points by the coulometric titration method in accordance with PN-EN ISO 12937:2005 standard.
The sample is assessed visually. If it is clear, transparent and free from water droplets and solid particles visible during the swirl, the weighed part is injected into the titration cell of the Karl Fisher coulometric instrument. In the apparatus, iodine for the Karl Fischer reaction is generated coulometrically at the anode. When all the water is titrated, the excess iodine is detected by the electrometer endpoint sensor and the titration is discontinued. The stoichiometry of reaction shows that one mole of iodine reacts with one mole of water, from this reason the amount of water is proportional to the total sum of the current according to the Faraday’s law. If the sample is not transparent and clear or if water droplets, as well as solid particles, are observed during the swirl, aliquots of the sodium dioctyl sulfosuccinate solution are added to the sample before the sample is homogenized using a stirrer.
Range: 0.003-0.100% (m / m)
11. Determination of the distillate fuel oil resistance to oxidation in accordance with PN-EN ISO 12205:2011 standard.
The method of determining the natural oxidation stability of medium fuel distillates under accelerated oxidation conditions. The method does not apply to fuels containing residual components or significant quantities of non-petroleum components. The sample of the filtered middle distillate fuel is subjected to an ageing process at 95 ° C for 16h with an oxygen flow through the sample. After the ageing process, the sample is cooled to the room temperature. Then is filtered to determine the insoluble filtering deposits content. Adhering insoluble impurities are removed from the oxidation kit and other glass parts with a solvent. The sum of adhering insoluble sediment and filtered insoluble sediments is given as a total insoluble sediments.
Range: 1-30 g / m3
12. Determination of the pour point by the manual mathod in accordance with PN-ISO 3016:2005 standard.
After the initial heating, the sample is cooled at a determined quench rate. In order to check its liquidity, the sample is controlled at 3 ° C intervals. The lowest temperature at which the movement of liquids is observed is considered as the flow temperature value.
Range: (-35) -35 ° C
13. Cetane index calculation of fuels in accordance with PN-EN ISO 4264:2010/A1:2013:07 standard.
The higher cetane index, the greater ignition potential of the compressed fuel mixture. The higher cetane index, the easier engine cold start and the better fuel combustion process. It is a parameter closely related to the cetane number. The higher cetane index, the stronger fuel. Density at 15 ° C and temperatures at which product distils 10% (V / V), 50% (V / V), and 90% (V / V) are determined by standardized test methods. On that bases, the cetane index data is calculated using well-known dependences.
The recommended range of fuel properties according to PN-EN ISO 4264: 2010 standard.
||The recommended range|
|Density at 15oC, kg/m3||805,0-895,0|
|Distilation temperature 10% (V/V),°C||171-259|
|Distilation temperature 50% (V/V),°C||212-308|
|Distilation temperature 90% (V/V).°C||251-363|
14. Cetane index calculation by the engine methode in accordance with PN-EN ISO 5165:2003 standard.
The Cetane Number (CN) is an indicator of the diesel self-ignition capacity. It is one of the diesel basic parameter, dependent on its chemical composition. The diesel fuel CN for spontaneous ignition engines is determined by comparing its ignition properties with analogous properties of reference fuel mixtures with determined cetane numbers.The test is carried out under standard conditions by using the test engine. The determination is made by using the “bracketing” procedure. Created from the final scale readings on the sample engine combustion and each of the two “bracketing” reference fuels; in order to obtain the ignition relative time delay that allowing for CN interpolation based on readings on the knob scale.
15. Cold filter plugging point in accordance with PN-EN 116:2001 standard.
The fuel sample is cooled under strictly defined conditions, then is sucked into the pipette at 1 ° C intervals under a controlled vacuum of 2 kPa through the standardized sulfur filter. The procedure is repeated after each 1 ° C fuel temperature reduction, starting with the temperature of the first determination. The determination is carried out until the paraffin crystals amount evolved from the solution will stop or slow down the flow of fuel in such a way that the pipette filling time exceeds 60 s or the fuel does not flow back completely to the measuring vessel before the next 1 ° C of cooling. The temperature of the blocked cold filter (CFPP) is the temperature during which the last filtration is taken.
Range: (-35) -0 ° C
16. Oxidation stability in accordance with PN-EN 15751:2014-05 standard.
Oxidation stability is one of the basic operational properties determined for fuel used in compression-ignition engines. The fuel oxidation leads to the various types of sediments, resins and acids formation. These products, by settings on the ends of the injectors, may interfere with the fuel injection process and as a result can damage fuel pumps, block filters and fuel lines. Acid oxidation products may cause the engine elements degradation by increasing corrosion and rapid destruction of various types of seals. A stream of purified air is passed through the sample which temperature is brought to a specified value. Volatile compounds, that are released from the sample in the oxidation process, pass through the air into a vessel containing demineralized or distilled water and equipped with a conductivity measuring electrode. The electrode is connected to the measuring and recording unit. It indicates the end of the indication period when the conductivity starts to increase rapidly. Accelerated growth is caused by the volatile carboxylic acids dissociation, which is formed in the oxidation process and is absorbed in water.
Range: 0,5-30 h
17. Inherent resin content the weight method in accordancie with PN-EN ISO 6246:2001 standard.
The presence of resins is a residue from evaporation of aviation fuels. They have not been subjected to any treatment. The sample measured volume is subjected to evaporation under controlled conditions of temperature and air or steam flow. The residue obtained from the test is weighed and can be further processed by solvent washing and subsequent weighing.
Range: 1-10 mg/ml
18. Determination of the fuel resistance to oxidation by the inductive period method in accordance with PN-EN ISO 7536:2011 standard.
The method determines the aviation fuel and motor gasoline resistance under accelerated oxidation conditions. It consist in measuring the induction period to the point of refraction, which is conducted in a pressure bomb equipped device. The sample is oxidised in a pressurebombet, that is previously filled with oxygen at 15 ° C to 25 ° C at 690 kPa and heated to a temperature between 98 ° C and 102 ° C. The pressure is read at regular intervals or continuously recorded until the break point is reached. The time necessary to reach this point is observed by the induction period at the determination temperature from which the induction period at 100oC temperature can be calculated.
Range: over 15 min
19. Determination of the saturation vapor pressure by the Reid method in accordance with PN-EN 13016-1:2009, ASTM D 5191-13 standards.
In this method, the vapour pressure of non-viscous liquids such as liquid fuels: aviation gasoline, gasoline components, liquid biofuels, is automatically determined. A cooled, air-saturated sample of known volume is injected into an emptied thermostated chamber or into a chamber where the vacuum is created after moving the plunger.The chamber internal volume is five times greater than the total volume of the introduced analytical sample. After injection, the sample is allowed to reach a thermal equilibrium at a test temperature of 37.8 ° C. The total pressure obtained during the procedure is equivalent to the sum of the sample vapour pressure and the dissolved air partial pressure.It is measured by using a sensor with a pointer. The measured total vapour pressure can be converted to a dry pair equivalent (DVPE) by using the correlation equation.
Range: 20,0-100,0 kPa
20. Determination of the Research Octane Number (ROB) by the engine method in accordance with PN-EN ISO 5164:2014-08 standard.
The Research Octane Number (ROB) is the knock resistance measure of fuels which are used in motor vehicles with spark ignition engines at moderate engine loads. The fuel sample, that is feeding the Cooperative Fuel Research (CFR) engine, is compared with the mixtures of the basic reference fuels. This procedure is conducted, in order to choose the mixture, which feeds the engine working at the fuel-to-air ratio, ensuring the maximum throttle intensity and demonstrate, with the same engine compression ratio, the same standardized intensity of the knob as the tested fuel. The basic reference fuel mixtures volume composition determines the octane number of the chosen mixture of basic reference fuels as well as the octane number of the test fuel sample.
21. Determination of the Motor Octane Number (MON) by the engine method in accordance with PN-EN ISO 5163:2014-08, ASTM D2700-14 standards.
The Motor Octane Number (MON) is the knock resistance measure of fuels used in motor vehicles for spark ignition engines at high engine loads. The fuel sample supplies the Cooperative Fuel Research (CFR) engine. Next, the sample is compared with the basic reference fuels to select a mixture that feeds the working engine at the same fuel-air ratio. This allows achieving maximum torsional stress. It also shows, with the same engine compression degree, the same knob standardized intensity as the tested fuel. The basic fuels volume composition of the reference fuels determines the chosen mixture octane number of the basic reference fuels and (at the same time) the octane number of the tested fuel sample.
80,0-90,0 for PN-EN ISO 5163:2014-08 standard.
85,0-103,5 for ASTM D2700-14 standard.
22. Determination of the crystallisation temperature by automated method in accordance with ASTM D 7153-15 atandard and by visual method in accordance with ASTM D 2386-15e1 standard.
The method includes the temperature determination, below which solid hydrocarbon crystals are produced. The sample is cooled in a very precisely controlled manner until the crystals are formed and then heated until they melt. The fuel crystallization point is defined as the temperature at which the last fuel crystals, which was previously cooled to separate the hydrocarbon crystals, are melted.
(-80)-(-40)°C by automated method
(-40)-(-60)°C by visual method
23. Determination of the exposure with water by the visual method in accordance with ASTM D 1094-07 standard.
The method involves determining the water miscible components presence in aviation fuel and gasoline. During the test, the fuel sample is shaken with the phosphate buffer solution. The changes in the volume and appearance of the water layer are treated as the interaction of fuel with water. If, during the mixing of aviation fuel and water there, a change in the volume of the water phase is noticed, it indicates the presence of the water-soluble compound e.g. alcohol.
24. Determination of the electrical conductivity by the conductometric method in accordance with ASTM D 2624-15 standard.
The fuel electrical conductivity is a crucial parameter that is related to the fuel safe operation. It is particularly important for fuels used in aviation. This method includes determining the electrical conductivity of aviation fuels and gasoline components. The measurement is carried out using the conductometric method.
Range: 50-600 pS/m
25. Determination of the resistance to oxidation by the weight method in accordance with ASTM D 873-12 standard.
The method determines the propensity to oxidize aviation fuel and gasoline components. The fuel sample is oxidated under certain conditions in a pressurized container filled with oxygen. Next, the amount of generated sediment is determined by using the weight method. The result is useful for indicating the fuels durability during storage.
Range: 1-8 mg/100ml
26. Determination of the resins content by the weight method in accordance with ASTM D 381-12 standard.
Resins content is the basic indicator which evaluates the fuel propensity for the sediment formation. In the high-temperature zone (valves, the piston bottom, the combustion chamber, etc.), sediment gradually burns out, leading to the so-called carbon deposits formation. During the measurement, the sample evaporates under controlled conditions of temperature and air flow. The residue is weighed and the result obtained in mg / 100ml.
Range: 1-8 mg/100ml
27. Determination of the aniline point by the C manual method in accordance with ASTM D 611-12 standard.
The aniline point is in other words the temperature at which the aniline phases and gasoline mixture are separated. The test indicates the presence of aromatic hydrocarbons in gasoline. Knowledge of the aniline point value is extremely useful in the pure hydrocarbons and hydrocarbon mixtures characterization. This method includes determining the aniline point in aviation gasoline and gasoline components. Method C is used for samples which significantly evaporate at the aniline point.
28. Determination of the net calorific value by the calculation method in accordance with ASTM D 4529-01 (2011), ASTM D 3338/D3338M-09 (2014) standards.
The calorific value is the amount of usable heat energy released when a fuel is burned under conditions similar to those in which it is normally used. This method allows determining the amount of heat released while burning aviation fuels at constant pressure. these three elements: the aniline point, density and sulfur content allows the calculation of the combustion heat of combustion using the known correlations.
Range: 40-50 MJ/kg
29. Determination of the aromatic hydrocarbon content by high-performance liquid chromatography (HPLC) in accordance with PN-EN 12916:2008 standard.
The sample with the defined mass is diluted with heptane. Next, the constant volume of this solution is injected into a high-performance liquid chromatography (HPLC) equipped with a polar column. The column indicates a small affinity for non-aromatic hydrocarbons, while being highly selective towards aromatic hydrocarbons. As a result, the separation of non-aromatic hydrocarbons from aromatic hydrocarbons takes place in various ranges. The process depends on the hydrocarbons ring structure such as mononuclear aromatic hydrocarbons, bicyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons. The column is connected to a refractive index detector that detects components as they elute from the chromatography column.
|III- and more rings||(0-2)%(m/m)|
|Polycyclic aromatic hydrocarbons (PAH)||(1-12)%(m/m)|
|Sum of aromatic hydrocarbons||(7-42)%(m/m)|
30. Determination of the hydrocarbons group content by the fluorescent indicator adsorption (FIA method) in accordance with PN-C-04100:2004 PN-EN 15553:2009 standard.
The sample is placed into a special glass adsorption column filled with activated silica gel. The thin layer of a silica gel contains a mixture of fluorescent dyes. After adsorbing of the silica gel, alcohol is introduced to desorber. Hydrocarbons are separated according to their sorption affinity to aromas, olefins and saturated. Fluorescent dyes are also selectively separated along with the hydrocarbon groups. This enabled the aroma, olefin and saturated ultraviolet visualization zones. The content of each hydrocarbon group is expressed as a volume fraction in percent and calculated from the length of each zone in the column.
(5-99) % (v/v) – Aromatic hydrocarbon:
(0,3-55) % (v/v) – Olefinic hydrocarbons
(1-95) % (v/v) – Saturated hydrocarbons
31. Determination of the lead content by the Flame Atomic Absorption Spectrometry (FAAS) in accordance with PB/AS-23 wg PN-92/C-04195 standard.
The procedure includes the lead determination of ethylene petrol with tetraethyl or tetramethyl lead by atomic absorption spectrometry in accordance with PN-92 / C-04195 standard. The atomic absorption spectrometer Fee Pye Unicam LTD is used in the measurement, equipped with a slit burner and a lead cathode lead-in lamp.
Range: 0,025-1,32 g/l
31a. Determination of the lead content by the Flame Atomic Absorption Spectrometry (FAAS) in accordance with ASTM D 3237-12 standard.
The method determines the total lead content in gasoline. This method is used to ensure traceability of trace lead content in accordance with the regulations for unleaded petrol. The sample is diluted and stabilized. Lead contained in the sample is determined by using flame atomic absorption spectrometry.
Range: 2,5-25 mg/l
32. Determination of the lead content by the Wavelength Dispersive X-ray Fluorescence (WDXRF) in accordance with ASTM D 5059-14 met. A IP 228/72 (2014) met. A, ASTM 5059-14 met. C. standard.
The lead additive to gasoline prevents its incorrect combustion, which increases its octane number. On the other hand, lead has a very adversely affects the catalytic afterburners and may cause their damage. Moreover, lead compounds present in fuel and in combustion gases have a negative impact on the natural environment and human health. Using this method, the content of lead in fuels is determined. Lead in fuels is derived from alkyl additives, which are intended to improve its anti-knock properties.
A method 0,04-1,032 g/l
C method 0,0026-0,132 g/l
33. Determination of the lead content by the titrations in accordance with D 3341-05 (2016) standard.
This method is used to determine the total lead content in gasoline derived from anti-knock additives. The sample of given volume is diluted with a heavy distillate and shaken with an aqueous solution of iodine monochloride. Each present tetraacrylic compound reacts with iodine monochloride and is extracted into the aqueous phase as a lead dialkyl. The aqueous phase is separated from the gasoline and evaporated to a small volume in order to decompose the free iodine monochloride.Each present organic matter is eluted with nitric acid, that also serves to convert lead dialkyl compounds into inorganic lead compounds.The residue is dissolved in distilled water and buffered to pH 5. The lead remaining in the buffered solution is determined by EDTA titration with orange xylenol as an indicator.
Range: 0,026-1,3 g/l
34. Determination of low lead content by the Flame Atomic Absorption spectroscopy (FAAS) in accordance with PN-EN 237:2007 standard.
The lead added to gasoline prevents its incorrect combustion, what increases its octane number. On the other hand, lead adversely affect on the catalytic afterburners that are resulted in their destruction. Lead compounds present in fuel and combustion have also a negative impact on the natural environment and human health. The tested sample which is diluted tenfold with isobutyl methyl ketone. Next iodine is given and the sample is aspirated into the flame of the acetylene-air atomic absorption spectrometer. Absorbance is measured at a wavelength of 217.0 nm and compared with the absorbance of the standard solutions with marked lead content.
Range: 2,5-10 mg/l
35. Determination of benzene content by the Fourier-Transform Infrared spectroscopy (FTIR) in accordance with PN-EN 238:2000+A1:2008.
Benzene is used in the chemical industry as a starting material in the organic synthesis. It is a high-energy component of motor gasoline. During the test, an infrared spectrum is recorded in the range from 730 cm-1 to 630 cm-1 of the sample previously diluted with cyclohexane.The absorbance is measured at 673 cm-1 and compared with the standard benzene solutions absorbance. The benzene content is obtained in g / 100 ml and it is converted into a volume fraction or mass or percentages.
Range: 0,1-20 % (v/v)
36. Determination of external appearance by the visual method in accorcance with NO-91-A235:2007 pkt. 4 ASTM D 4176-04 (2009) 1st methode standard.
The tested sample shall be poured into a glass cylinder made of clear glass. Then the external appearance of the sample is visually assessed in the passing light. The test is carried out at a temperature of (20 ? 5) ° C. It is recognised that the aviation fuel meets the requirements if during the test if the liquid is clear, without sediment, turbidity and undissolved water.
37. Determination of colour in Lovibond-RYBN units by the colorimetric method in accordance with IP 17:2010 standard.
The procedure of colour determining of dyed and undyed petroleum products. Solid and semi-solid products, such as petrolatum and waxes, are tested in a liquid state. This procedure is based on a three-colour scale (red, yellow, blue) and measures the colour intensity in Lovibond units.
38. Determination of colour in Lovibond-RYBN units by the colorimetric method in accordance with IP 569/09 standard.
The procedure of automatical colour determining of dyed and undyed petroleum products. The light passes through the sample of liquid petroleum products or liquid wax and falls onto the detector. The result is presented in Lovibond units (red, yellow, blue and neutral) as the sample colour.
39. Determination of colour by the visual method in accordance with ASTM 2392-15 standard.
The aviation gasoline is coloured with different colours in order to facilitate the identification of its type. It minimizes the risk of misfuelling the aircraft. This method determined the acceptability of dyed aviation gasoline.
40. Determination of carbon residue by the weight method in accordance with PN-EN ISO 10370:2014:12 standard.
Carbon reduce is the total residue obtained after evaporation and thermal decomposition of petroleum product under specific conditions. A weighed portion of the oil sample is placed in a glass vial and then heated to 500 ° C in a stream of inert gas (nitrogen) under controlled conditions for a specified period of time. Volatile substances formed during the reaction are removed with an inert gas. The charred residue is weighed.
Range: 0,1-16 % (m/m)
41. Determination of sulphur content by the Wavelength Dispersive X-ray Fluorescence (WDXRF) method in accordance with PN-EN ISO 14596:2009, ASTM D 2622-10, PN-EN ISO 20884:2012 standards.
The sulfur content in the fuel has a great ecological importance. Too much of sulfur causes exhaust gases quality deterioration and may damage the exhaust gas catalyst. The method includes the determination of total sulfur content in petroleum and petroleum products. The analytical sample is exposed to the original X-ray radiation of the X-ray tube. During the measurement, the intensity of the peak from sulfur (0.5373 nm) is measured. The value obtained is then referred to the previously prepared standard curve in order to obtain the sulfur content.
0,001-2,5% (m/m) – for PE-EN ISO 14596:2009 standard
0,0003-2,5 % (m/m) – for ASTM D 2622-10 standard
5-500 mg/kg – for PN-EN ISO 20884:2012 standard
42. Determination of sulphur content by the ultraviolet (UV) fluorescence test method in accordance with ASTM D 5453-09, PN-EN ISO 20846:2012 standartds.
The method is used to determine the total sulfur content of liquid hydrocarbons which boiling point is between 25 and 400 ° C and have a viscosity in the range of 0.2-20 mm2 / S at the room temperature. The sample is injected directly or placed in the introducer boat. The sample is introduced into the combustion tube. Then, at high temperature, the sulfur atom is oxidized to sulfur dioxide (SO2) in the atmosphere rich in oxygen. Water produced in combustion is removed and then the exhaust gases of the sample are exposed to ultraviolet (UV) radiation. SO2 absorbs energy from UV radiation and as a result, comes to the sulfur dioxide (SO2 *) excitation. Fluorescence emission occurs during the transition from the excitation state SO2 to its ground state. SO2 is detected by photomultiplier tubes. The obtained signal is a measure of sulfur contained in the sample.
1-1050 mg/kg – for ASTM D 5453-09 standard.
3-500 mg/kg – for PN-EN ISO 20846:2012 standard.
43. Determination of Fatty Acid Methyl Esters (FAME) by the Fourier-transform infrared spectroscopy (FTIR) method in accordance with PN-EN 14078:2014-06 standard.
The analytic sample is first taken from the sample which is previously dilution with a non-FAME solvent. Then, the spectrum of the analytical sample is recorded in the mid-infrared range. Absorbance is measured at the peak maximum characteristic of the absorption band esters at about (1745 ? 5) cm-1. The FAME content is calculated on the basis of the maximum absorption peak band, by using a standard curve. The standard curve is based on measuring of standard solutions of known FAME content.
Range: 0,5-22,7 % (v/v)
44. Determination of external appearance by the visual method in accordance with PB/AS-91 standard.
The procedure defines the external appearance of engine fuel samples (gasoline, diesel oil), light fuel oil, biofuels and liquid biocomponents. The method consists in the visual inspection of the sample with an unaided eye.
45. Determination of the total hydrocarbons C6-C36 by the gas chromatography (GC) method in accordance with PB/ACH-100 standard.
The aim of the method is to extract hydrocarbons from the water sample by the means of n-pentane, followed by the chromatographic analysis of the resulting extract by gas chromatography. The measurement is carried out using a gas chromatograph 7890A which is equipped with a flame ionization detector (FID) and a capillary column.
Range: 0,02-150 mg/l
46. Determination of the petroleum hydrocarbons C6-C12 and oil hydrocarbons C12-C35 content by the gas chromatography (GC-FID) method in accordance with PB/ACH-81 standard.
The aim of the procedure is the quantitative determination of the petroleum hydrocarbons C6-C12 and oil hydrocarbons C12-C35 content, expressed in mg/kg of dry matter in soil samples by gas chromatography. The method consists extracting hydrocarbons from the test sample with n-pentane in the Soxtec Avanti 2050 extractor. Next, polar components are removed by adsorption on florisil / sodium sulfate columns and then the final sample of the purified extract undergo chromatographic analysis by using a gas chromatograph which is equipped with a flame ionization detector. The apparatus provides a strict separation petroleum hydrocarbons from oil hydrocarbons.
C6-C12 30-1000 mg/kg s.m.
C12-C35 30-4000 mg/kg s.m.
47. Determination of the petroleum hydrocarbons C6-C12 by the gas chromatography (GC) in accordance with PB/ACH-124 standard.
The aim of the method is the quantitative determination of trace hydrocarbon content in soils by using gas chromatography following the headspace technique. Measurement is performed using an HP 5890 SII gas chromatograph that is equipped with a Flame Ionization Detector (FID).
Range:1-30 mg/kg s.m.