1) Analysis of Ultra Low Sulfur in Automotive Fuels According to ASTM D by Sulfur Analyzer Micro-Z ULS (Rigaku Application Note XRF1053)

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1 Dear Scientist, XRF ۱۰٥۳ Thank you for downloading this short application compendium for low sulfur analysis in fuel oils. Rigaku Corporation and Gulf Bio Analytical are pleased to bring you this resource and hope that it will be a useful for you in developing protocols for ultra low sulfur analysis in your laboratory. The guide is divided into the following sections: 1) Analysis of Ultra Low Sulfur in Automotive Fuels According to ASTM D by Sulfur Analyzer Micro-Z ULS (Rigaku Application Note XRF1053) 2) Analysis of Low Concentration Sulfur in Automotive Fuels by Mini-Z Sulfur Analyzer According to ASTM D (Rigaku Application Note 5035) 3) EDXRF Application Note: Sulfur in Crude as per ASTM D4294 (Rigaku Application Note 1149) 4) EDXRF Application Note: Sulfur in Diesel as per ASTM D4294 5) Simultaneous Analysis of Sulfur and Ultra-Low Chlorine in Crude Oil by EDXRF (Rigaku Application Note 1432) 6) Analysis of Low Concentration Sulfur in Petroleum-based Fuels by Benchtop WDXRF According to ASTM D Gulf Bio Analytical - Your trusted partner in the Middle East for Rigaku Coporation s Energy Dispersive X-ray Fluorescence (EDXRF) and Wavelength Dispersive X-ray Fluorescence (WDXRF) Spectroscopy Solutions Established in 1999 in Dubai, United Arab Emirates, Gulf Bio Analytical LLC (GBA) today, is a recognized leader in providing comprehensive laboratory solutions to the hydrocarbon processing and analytical sciences industries in the Middle East, India and S. E. Asia. From our headquarters in Dubai and all our regional offices we are able to efficiently serve the growing laboratory clientele in these regions. We represent world leading scientific and analytical equipment manufacturers and partner with them to provide value added and cost-effective services to our esteemed clientele. All our offices are equipped and staffed to handle end-to-end business functions such as sales, service, logistics, distribution, warehousing, accounts, etc. ۱

2 XRF 1053 Analysis of Ultra Low Sulfur in Automotive Fuels According to ASTM D by Sulfur Analyzer Micro-Z ULS fuel oil petroleum Benchtop wavelength dispersive X-ray fluorescence spectrometer Micro-Z ULS automotive fuels ultra low sulfur diesel fuel gasoline ASTM benchtop sulfur analyzer Introduction Recent developments in ultra low sulfur (ULS) fuel have improved fuel efficiency and created cleaner exhaust gases. Globally, the permitted sulfur limit in fuel oils has been decreased to 10ppm in many countries and regions. For compliance verification, X-ray fluorescence (XRF) spectrometry is the definitive analysis tool for use at distribution terminal and refineries, as well as mobile or stationary testing laboratories. In recent years, there has been an increasing need for an instrument which does not require the use of helium gas, for instances, when acquisition or delivery of helium to the analysis site is difficult. The Micro-Z ULS (ultra low sulfur) is a newly developed Sulfur analyzer which does not require helium gas in operation. This application note demonstrates that Micro-Z ULS can meet the requirements of ASTM D Instrument The Micro-Z ULS is a benchtop wavelength dispersive X-ray fluorescence (WDXRF) spectrometer with fixed optics optimized for sulfur analysis. The atmosphere in the optics path of the Micro-Z ULS, is a vacuum, so that helium gas is not required. The spectrometer is designed to minimize the restrictions in installation such as cooling water, special power supply, installation space, etc. The Micro-Z ULS is equipped with an air-cooled 40 W Cr-target X-ray tube and a doubly curved RX-9 analyzing crystal optimized for low concentration sulfur. The Micro-Z ULS has a built-in operation panel, which enables simple and easy operation for daily analysis. The counting time was 300 seconds for peak and background measurements in this experiment. Sample preparation Four ml of each sample was poured into a liquid cell (inner diameter 35 mm) with sample film of 2.5 μm Mylar film (Chemplex 100). Standard and calibration Number 2 diesel fuel standards and isooctane-based standards provided by VHG Labs, inc. were used for calibrations of diesel fuel and gasoline respectively. The calibration results are listed in Table 1 and the calibration curves are shown in Figure 1. Table 1 Calibration result for each material using Micro-Z ULS (unit: mg/kg) Material Diesel fuel Isooctane (for gasoline) Calibration range Accuracy LLD

3 XRF 1053 The accuracy of calibration is calculated by the following formula, Accuracy= i ( C Ĉ ) i n m C i : reference value of standard sample Ĉ : calculated value of standard sample i n : number of standard samples m : degree of freedom (2: linear). The lower limit of detection is calculated by the following formula, LLD= 3 1 σ m B = 3 m i 2 IB 1000 t m : sensitivity of calibration (kcps/[mg/kg]) σ B : standard deviation of blank intensity (kcps) I B : blank intensity (kcps) t : counting time (s) (a) (b) Analysis results Repeatability tests were carried out using a representative sample for each material. For each sample, two aliquots were prepared and analyzed using the calibration Figure 1; this process was repeated twenty times. The test results are tabulated in Table 2 (a) for diesel fuel and (b) for gasoline, in which the average and the difference of two aliquots are shown respectively. r represents repeatability defined by the following formula in ASTM D , Repeatability (r) = X mg/kg (1) X: total sulfur concentration The difference between successive test results obtained by the same operator with the same apparatus under constant operation conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the values calculated by Equation (1) only in one case in twenty. The test results shown in Table 2, where the maximum value for each fuel is smaller than r, prove that the performance of the Micro-Z ULS meets the requirement of ASTM D for diesel fuel and gasoline. Conclusion Low concentration sulfur in petroleum-based fuel can be routinely analyzed with high accuracy and precision on the Micro-Z ULS, a benchtop WDXRF spectrometer with fixed optics, which does not require He gas, external water for cooling the X-ray tube or special power supply. This application note demonstrates that the performance of the Micro-Z ULS meets the requirement of ASTM D , which has become strict in the recent versions of ASTM D2622. Reference ASTM D (2010), Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry, ASTM International,12pp. Figure 1 Calibration curve for each material of Micro-Z ULS (a) Diesel fuel (b) Isooctane (for gasoline) 2

4 XRF 1053 Table 2 Repeatability test result for Micro-Z ULS (qualification test for ASTM D ) (a) Diesel fuel (b) Gasoline Run # Difference Run # Difference Avg. 8.2 Avg Maximum 0.7 Maximum 0.8 r (repeatability) 0.8 r (repeatability) 1.1 3

5 XRF 1053 Tokyo Branch , Sendagaya, Shibuya-ku, Tokyo , Japan Phone Fax Rigaku Corporation Head Office , Matsubara-cho, Akishima-shi, Tokyo , Japan Phone Fax Rigaku Corporation Osaka Factory 14-8, Akaoji-cho, Takatsuki-shi, Osaka , Japan Phone Fax Rigaku Americas Corporation 9009 New Trails Drive, The Woodlands, Texas , USA Phone Fax Rigaku Beijing Corporation 2601A, Tengda Plaza, No.168, Xizhimenwai Avenue, Haidian District, Beijing , P.R.China Phone Fax Rigaku Europe SE Am Hardtward 11, Ettlingen, Germany Phone Fax Rigaku Latin America Ltda. Rua Harmonia, 1232, Sumarezinho, CEP , São Paulo, SP, Brazil Phone Fax (K1118en)

6 XRF 5035 Analysis of Low Concentration Sulfur in Automotive Fuels by Mini-Z Sulfur Analyzer According to ASTM D fuel oil petroleum Benchtop wavelength dispersive X-ray fluorescence spectrometer Mini-Z Sulfur Analyzer automotive fuels sulfur diesel fuel gasoline ASTM benchtop by azza-bazoo Introduction Recent developments in ultra low sulfur diesel (ULSD) fuel has improved fuel efficiency and created cleaner exhaust gas and permitted limit of sulfur in fuel oils has been decreased to 10 or 15 ppm as the limit in most countries. There is a strong possibility that these regulations can become even more severe. For compliance verification, X-ray fluorescence (XRF) spectrometry is the definitive analysis tool for use at distribution terminal, as well as mobile or stationary testing laboratories. This application note demonstrates that Mini-Z Sulfur Analyzer can meet the requirements of ASTM D Instrument The Mini-Z Sulfur Analyzer (hereafter called Mini-Z S ), a benchtop single fixed-channel wavelength dispersive X-ray fluorescence (WDXRF) spectrometer, is designed to minimize the restrictions in installation such as cooling water, special power supply, installation space, etc. The Mini-Z S is equipped with an air-cooled 40 W Cr-target X-ray tube and the RX-9 analyzing crystal, optimized for sulfur analysis. The Mini-Z S has a built-in operation control panel, which enables simple and easy operation. The counting time was 300 seconds for peak and background measurements. The path atmosphere of the Mini-Z S is helium. Sample preparation Four milliliter of each sample was poured into a special liquid cell called Caplugs with analysis film of 2.5 μm Mylar film (Chemplex 100). Standard and calibration Number 2 diesel fuel standards and isooctane-based standards provided by VHG Labs were used for calibration for diesel fuel and gasoline respectively. The calibration results are listed in Table 1 and the calibration curves are shown in Figure 1. Table 1 Calibration result for each material using Mini-Z S (in mg/kg) Material Diesel fuel Isooctane (for Gasoline) Calibration range Accuracy LLD 0.3 The accuracy of calibration is calculated by the following formula, 1

7 Intensity Intensity Intensity Intensity XRF 5035 Accuracy i C i Ĉ n m C i : calculated value of standard sample Ĉ : reference value of standard sample i n : number of standard samples m : degree of freedom (2: linear). i 2 Analysis results Repeatability tests were carried out using a representative sample for each material. For each sample, two aliquots were prepared and quantified with the calibration Figure 1; this process was repeated twenty times. The test results are tabulated in Table 2 (a) for diesel fuel and (b) for gasoline, in which the average and the difference of two aliquots each are shown respectively. r represents repeatability defined by the following formula, The lower limit of detection is calculated by the following formula, Repeatability (r) = X mg/kg (1) X: total sulfur concentration LLD 3 (a) 1 m B 3 m IB 1000 t m : sensitivity of calibration (kcps/[mg/kg]) B : standard deviation of blank intensity (kcps) I B : blank intensity (kcps) t : counting time (s) in ASTM D , which states that the difference between successive test results obtained by the same operator with the same apparatus under constant operation conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the values calculated by Equation (1) only in one case in twenty. The test results shown in Table 2, where the maximum value for each fuel is smaller than r, prove that the performance of the Mini-Z S meets the requirement of ASTM D for diesel fuel and gasoline. Conclusion Standard value (ppm) Low concentration sulfur in petroleum-based fuel can be routinely analyzed with high accuracy and precision on the Mini-Z Sulfur Analyzer, a benchtop single fixed-channel WDXRF spectrometer, which does not require external water for cooling an X-ray tube or special power supply. This application note demonstrates that the performance of the Mini-Z Sulfur Analyzer meets the requirement of ASTM D , which has become strict in the recent versions of ASTM D2622. (b) Reference ASTM D Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry. Standard value (ppm) Figure 1 Calibration curve for each material of Mini-Z S (a) Diesel fuel (b) Isooctane (for gasoline) 2

8 XRF 5035 Table 2 Repeatability test result for Mini-Z S (qualification test for ASTM D ) (a) Diesel fuel (b) Gasoline Run # Difference Run # Difference Avg. 9.5 Avg Maximum 0.8 Maximum 1.0 r (repeatability) 0.9 r (repeatability) 1.3 3

9 XRF 5035 Tokyo Branch , Sendagaya, Shibuya-ku, Tokyo , Japan Phone Fax Rigaku Corporation Head Office , Matsubara-cho, Akishima-shi, Tokyo , Japan Phone Fax Rigaku Corporation Osaka Factory 14-8, Akaoji-cho, Takatsuki-shi, Osaka , Japan Phone Fax Rigaku Americas Corporation 9009 New Trails Drive, The Woodlands, Texas , USA Phone Fax Rigaku Beijing Corporation 2601A, Tengda Plaza, No.168, Xizhimenwai Avenue, Haidian District, Beijing , P.R.China Phone Fax Rigaku Europe SE Gross-Berliner Damm 151, Berlin, Germany Phone Fax (I0323)

10 XRF 1044 Analysis of Low Concentration Sulfur in Petroleum-based Fuels by Benchtop WDXRF According to ASTM D fuel oil petroleum Benchtop wavelength dispersive X-ray fluorescence spectrometer Supermini200 petroleum fuel oil sulfur diesel fuel gasoline kerosene ASTM benchtop by azza-bazoo Introduction Sulfur in petroleum-based fuels contributes to atmospheric pollution. Sulfur content in fuels, especially in automobile fuels, is strictly controlled and regulations of sulfur content in fuel oil, such as diesel fuel and gasoline, have been tightened. Therefore, control of sulfur content is very important in refineries. X-ray fluorescence (XRF) spectrometry has been used for quantitative analysis of sulfur in petroleum-based fuels, owing to simple sample preparation. In XRF analysis of fuel oil, the sample is simply poured into a plastic cup equipped with a transparent film without any complicated treatment, such as chemical decomposition or serial dilution. In addition, concentration of total sulfur is obtained in XRF analysis. This application note demonstrates quantitative analysis of low concentration sulfur in diesel fuel, gasoline and kerosene according to ASTM D on Rigaku Supermini200, a benchtop wavelength-dispersive X-ray fluorescence (WDXRF) spectrometer. Instrument The Supermini200 is a benchtop sequential WDXRF spectrometer designed specifically to deliver excellent performance while eliminating typical installation requirements, such as cooling water, special power supply, large floor space, etc. Featuring a unique air-cooled 200W X-ray tube, two detectors, programmable environment of vacuum or helium, and three analyzing crystals, the Supermini200 can analyze elements from fluorine to uranium. The Windows-based software running the Supermini200 is shared with Rigaku s popular Primus family of higher-power WDXRF systems, which means that it has the same advanced algorithms, multiple language support and an intuitive user-friendly interface. Measurements were performed on the Supermini200 using a PET analyzing crystal, included in the standard crystals, with the X-ray tube operating at 50 kv and 4.0 ma. The counting time was 300 seconds for peak and 150 seconds for background. Sample preparation Four milliliter of each sample was poured into a standard liquid cell (Chemplex 1540) equipped with 3.6 μm Mylar (Chemplex 150). Standards and calibration Number 2 diesel fuel standards, isooctane-based standards and kerosene-based standards provided by VHG Labs were used for calibration of diesel fuel, gasoline and kerosene respectively. The calibration curves are shown in Figure 1 and the calibration results are listed in Table 1. 1

11 XRF 1044 Table 1 Calibration result for each material (in mg/kg) Material Diesel fuel Gasoline Kerosene Calibration range Accuracy LLD 0.5 (a) Sulfur in diesel fuel The accuracy of calibration was calculated by the following formula, Accuracy= i ( C Ĉ ) i n m C i : calculated value of standard sample Ĉ : reference value of standard sample i n : number of standard samples m : degree of freedom (2: linear). i 2 (b) Magnified (0 mg/kg 100 mg/kg) Sulfur in gasoline The lower limit of detection was calculated by the following formula, LLD = 3 1 m σ B = 3 m IB 1000 t m : sensitivity of calibration (kcps/[mg/kg]) σ B : standard deviation of blank intensity (kcps) I B : blank intensity (kcps) t : counting time (s) Analysis results In order to assess the repeatability of the method, two aliquots of a representative sample were prepared and quantified with the calibration; this process was repeated twenty times. The test data are compiled in Table 2 (a) for diesel fuel, Table 2 (b) for gasoline and Table 2 (c) for kerosene, which show the average and the difference of the results of each two-aliquot measurement. ASTM D defines repeatability (r) by Repeatability (r) = X mg/kg (1) X: total sulfur concentration and states that the difference between successive test results obtained by the same operator with the same apparatus under constant operation conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the values calculated by Equation (1) only in one case in twenty. For diesel fuel and gasoline, other repeatabilities, which are not mandatory, are provided in Appendix of ASTM D Diesel fuel: r = X Gasoline: r = X X: total sulfur concentration These values for the test are also shown in Table 2 (a) and Table 2 (b) for reference. (c) Magnified (0 mg/kg 100 mg/kg) Sulfur in kerosene Figure 1 Calibration curve for each material (a) Diesel fuel (b) Gasoline (c) Kerosene Magnified (0 mg/kg 100 mg/kg) The test results shown in Table 2, where the difference of two aliquots does not exceed the repeatability (r) for each material, prove that the performance of the Supermini200 easily satisfies the requirement of ASTM D for diesel fuel, gasoline and kerosene. 2

12 XRF 1044 Table 2 Repeatability test result (qualification test for ASTM D ) (a) Diesel fuel (b) Gasoline (c) Kerosene Run # Difference Run # Difference Run # Difference Avg. 9.4 Avg. 9.5 Avg Maximum 0.8 Maximum 0.8 Maximum 0.7 r (repeatability)* 0.9 r (repeatability)* 0.9 r (repeatability)* 0.9 r in Appendix** 0.6 r in Appendix** 1.3 * This r is defined in the text of ASTM D and mandatory for qualification. ** This r is defined in Appendix of ASTM D and is not mandatory for qualification. Conclusion This application note desmonstrates that low concentration sulfur in petroleum-based fuel can be routinely analyzed with excellent accuracy, sensitivity and repeatability using a benchtop WDXRF spectrometer with minimal site requirements. In particular, the Rigaku Supermini200 benchtop WDXRF system, which does not require external water for cooling an X-ray tube or special power supply, meets the specification of ASTM D , which has become more stringent in the recent versions of ASTM D2622. Reference ASTM D Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry 3

13 XRF 1044 Tokyo Branch , Sendagaya, Shibuya-ku, Tokyo , Japan Phone Fax Rigaku Corporation Head Office , Matsubara-cho, Akishima-shi, Tokyo , Japan Phone Fax Rigaku Corporation Osaka Factory 14-8, Akaoji-cho, Takatsuki-shi, Osaka , Japan Phone Fax Rigaku Americas Corporation 9009 New Trails Drive, The Woodlands, Texas , USA Phone Fax Rigaku Beijing Corporation 2601A, Tengda Plaza, No.168, Xizhimenwai Avenue, Haidian District, Beijing , P.R.China Phone Fax Rigaku Europe SE Am Hardtward 11, Ettlingen, Germany Phone Fax Rigaku Latin America Ltda. Rua Harmonia, 1232, Sumarezinho, CEP , São Paulo, SP, Brazil Phone Fax (K1118en)

14 EDXRF APPLICATION NOTE SULFUR AND ULTRA-LOW CHLORINE IN CRUDE OIL # 1432 SCOPE The simultaneous analysis of sulfur and and ultra-low chlorine in crude oil is demonstrated. BACKGROUND Monitoring the sulfur and chlorine content is important in crude. In crude oil, chlorine may be present through natural processes or possible adulteration. If unmeasured or not corrected for, chlorine may bias the sulfur measurement or potentially cause corrosion damage in blending operation, in pipelines or during the refining process. The industry requires a fast, simple means of screening and monitoring the chlorine content of crude at the well site, along pipelines, during blending and other pre-refining checks. In these cases and others, Applied Rigaku Technologies meets the challenge of monitoring and measuring the sulfur and chlorine content of oils with the use of benchtop EDXRF instrumentation. The Rigaku NEX CG using indirect excitation and polarizations brings the industry a simple means to measure sulfur and chlorine simultaneously while delivering the lowest chlorine detection limits by EDXRF. INSTRUMENTATION Model: Rigaku NEX CG X-ray tube: 50 W Pd-anode Excitation: Indirect with polarization Detector: SDD Analysis Time: 300 sec Environment: Helium Purge Film: Prolene SAMPLE PREPARATION Ensure each sample is homogeneous and stable, it is recommended that water be removed prior to the XRF measurement. Shake sample gently and allow any bubbles to settle. Fill an XRF sample cup with 5g of sample to ensure consistent sample depth. Prolene film (4um) is used to ensure optimal X-ray transmission. Make the XRF measurement immediately after preparing the sample. Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

15 Calculated Calculated EDXRF APPLICATION NOTE # 1432 CALIBRATION Empirical calibration was built using a set of 8 commercially available certified standards. A summary of the empirical calibrations is shown here. S Calibration Element: S RMS: Units: % Correlation: I.D. Standard Calculated Std Std Std Std Std Std Std Std anchor 0 0 anchor Correlation Plot S Standard Cl Calibration Element: Cl RMS: 2.1 Units: ppm Correlation: I.D. Standard Calculated Std Std Std Std Std Std Std Std anchor 0 0 anchor Correlation Plot Cl Standard Page 2 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

16 EDXRF APPLICATION NOTE # 1432 REPEATABILITY To demonstrate repeatability (precision), the low and high chlorine calibration standards were selected. Each was measured in 10 repeat analyses using an analysis time of 300 sec per sample without moving the sample between measurements. Standard 1 Standard 8 Element Standard NEX CG Std Dev % Relative Element Standard NEX CG Std Dev % Relative S (%) Cl (ppm) S (%) Cl (ppm) DETECTION LIMIT The empirical method was used to determine the detection limit. In the empirical method, ten repeat analyses of a blank sample are taken with the sample in static position and the standard deviation is determined. To demonstrate LLD three different blanks were tested: Heavy mineral oil containing no sulfur or chlorine Sweet crude containing 0.5% sulfur and no chlorine Sour crude containing 1.5% S and no chlorine The Lower Limit of Detection (LLD) is then defined as three times the standard deviation of the ten repeat analyses. The following typical LLDs are reported here using a measurement time of 300 sec. Element S Cl LLD <1.0 ppm 0.3 ppm in crude up to 1.5% sulfur CONCLUSION The results shown here indicate that given stable, homogeneous samples the Rigaku NEX CG EDXRF analyzer gives superior performance for the measurement of sulfur and chlorine in oil. The versatility of the NEX CG for multi-element analysis make it an ideal tool for measuring many other elements and oil matrices such as lube oils, wear metals in oils, used oils and waste oil, as well as ultra-low sulfur measurement in diesel and gasoline, giving the user versatility for analysis throughout the petroleum industry. Page 3 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

17 EDXRF APPLICATION NOTE SULFUR IN CRUDE # 1149 SCOPE The analysis of sulfur in crude oil as per ASTM D4294 is demonstrated. The performance shown is applicable to: light and heavy crude oils residual oil bunker fuels BACKGROUND Sulfur will always be an important element in crude oils and fuels oils. Sulfur content is regulated in many products, and plays an important role in fuel quality and control of polluting emissions. Around the world regulations are limiting the amount of sulfur allowable in diesel fuels, kerosene, heating oils, etc., thus affecting the price and quality of crude oil based on sulfur content of the crude. Reliably characterizing the sulfur content of crudes ensures proper quality for the various feedstocks at the refinery, and optimum blending ratios when blending different crudes to meet a desired sulfur concentration. Monitoring sulfur is also very important when characterizing other similar oils, like residual oils and bunker fuels. To meet the needs of the industry, Rigaku offers NEX QC, a simple and versatile benchtop EDXRF analyzer for the analysis of sulfur and other elements in crude oil, petroleum oils and fuels. INSTRUMENTATION Model: X-ray tube: Detector: Sample Type: Film: Analysis Time: Environment: Optional: Rigaku NEX QC 4 W Ag-anode Semiconductor Crude oil Mylar 100 sec Air Autosampler SAMPLE PREPARATION To measure a sample, gently shake the sample bottle, allow bubbles to settle and fill a 32mm XRF sample cup 3/4 full (5g). Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

18 Calculated EDXRF APPLICATION NOTE # 1149 LOW RANGE: % Sulfur CALIBRATION An empirical calibration was built using a set of commercially available certified crude oil standards. Goodness-of-fit is optimized by developing separate calibration methods for different sulfur ranges, if needed. A summary of the calibration for S is shown here, using a measurement time of 100 sec. Element: S Units: % Std Error of Est: Correlation: Sample I.D. Standard Calculated STD STD STD STD STD Correlation Plot S Standard REPEATABILITY To demonstrate repeatability (precision), the select samples were chosen from the set of calibration standards. Each sample was measured in static position for ten repeat analyses using a total analysis time of 100 sec per measurement, with typical results shown below. Element: S Units: % Sample ID Standard Std Dev % Relative STD STD Page 2 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

19 Calculated EDXRF APPLICATION NOTE # 1149 HIGH RANGE: % Sulfur CALIBRATION An empirical calibration was built using a set of commercially available certified crude oil standards. Accuracy is optimized by developing separate calibration methods for different sulfur ranges, if needed. A summary of the calibration for S is shown here, using a measurement time of 100 sec. Element: S Units: % Std Error of Est: Correlation: Sample I.D. Standard Calculated STD STD STD STD STD STD Correlation Plot S Standard REPEATABILITY To demonstrate repeatability (precision), the select samples were chosen from the set of calibration standards. Each sample was measured in static position for ten repeat analyses using a total analysis time of 100 sec per measurement, with typical results shown below. Element: S Units: % Sample ID Standard Std Dev % Relative STD STD Page 3 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

20 EDXRF APPLICATION NOTE # 1149 MULTI-ELEMENT VERSATILITY The NEX QC is capable of measurement more than just sulfur. Multi-element analysis is important for detecting crude oil contamination or adulteration by the presence of salt and other chlorine-bearing compounds. Left undetected, the presence of Cl can bias the S reading high and potentially leave the leave the presence of Cl unnoticed. NEX QC has the ability to detect Cl and other elements, and correct for the presence of Cl so that its presence is noticed and does not bias the S reading. Sweet crude 0.5% S containing no Cl Sweet crude oil contaminated with Cl If unnoticed and uncorrected, the Cl will bias the sulfur reading high Page 4 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

21 EDXRF APPLICATION NOTE # 1149 TYPICAL DETECTION LIMITS To determine the Lower Limit of Detection (LLD) using the empirical method, ten repeat analyses of mineral oil containing no S were measured and the standard deviation calculated. The LLD is then defined as three times the standard deviation. S 100 sec S 600 sec 20 ppm 8 ppm INTERNATIONAL STANDARD TEST METHODS The Rigaku NEX QC complies with the following international standards test methods for measuring sulfur in crude and petroleum oils. Note that by weight 1 ppm = 1 mg/kg. ASTM D4294 ISO ISO 8754 IP 496 IP336 JIS K ppm 5% mg/kg 100 mg/kg 5% 100 mg/kg 5% 100 mg/kg 5% % CONCLUSION The performance shown here demonstrates the ability of the NEX QC to yield excellent results for the measurement of crude oil and other heavy petroleum oils in air, without the need for helium purge. Simple, modern touch screen interface allows for reliable and efficient measurement protocols, and performance meets the major international norms shown above. Page 5 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

22 EDXRF APPLICATION NOTE SULFUR IN DIESEL # 1135 REV1 SCOPE The analysis of sulfur in diesel fuel as per ASTM D4294 is demonstrated. BACKGROUND Sulfur will always be an important element in crude oils and fuels oils. Sulfur content is regulated in many products, and plays an important role in fuel quality and control of polluting emissions. Around the world regulations are limiting the amount of sulfur allowable in diesel fuels, kerosene, heating oils, etc. Jet fuels also rely on the sulfur content to ensure optimum fuel properties, in addition to emission concerns. Therefore, from characterizing, blending and refining crude oil to the production of various fuel oils, monitoring sulfur content will continue to be a very important measurement. To meet the needs of the industry, Rigaku offers NEX QC, a simple and versatile benchtop EDXRF analyzer for the analysis of sulfur and other elements in petroleum oils and fuels. INSTRUMENTATION Model: Rigaku NEX QC X-ray tube: 4 W Ag-anode Detector: Semiconductor Sample Type: Diesel fuel Film: Mylar or Prolene Analysis Time: 120 sec Standard Range, in Air (240 sec during calibration) 300 sec Low Range, in Helium Environment: Air or Helium Optional: Autosampler SAMPLE PREPARATION To measure a sample, gently shake the sample bottle, allow bubbles to settle and fill a 32mm XRF sample cup 3/4 full (5g). Mylar film is used for the standard range and higher levels, and Prolene film is used to optimize the low sulfur range of ppm S. Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

23 Calculated EDXRF APPLICATION NOTE # 1135 REV1 CALIBRATION Standard Range An empirical calibration was built using a set of commercially available certified diesel fuel standards. Separate calibration methods can be built for different sulfur ranges, if needed. A summary of the calibration is shown here, using a measurement time of 240 sec in air atmosphere. Element: S Units: ppm Std Error of Est: 4 Correlation: Sample I.D. Standard Calculated STD STD STD STD STD STD Correlation Plot S Standard REPEATABILITY Standard Range To demonstrate repeatability (precision), the select samples were chosen from the set of calibration standards. Each sample was measured in static position for ten repeat analyses using a total analysis time of 120 sec per measurement in air atmosphere, with typical results shown below. Element: S Units: ppm Sample ID Standard Std Dev % Relative STD STD Page 2 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

24 Calculated EDXRF APPLICATION NOTE # 1135 REV1 CALIBRATION Low Range The low sulfur range ppm uses typical ULS technique protocol: Prolene film Helium purge 300 sec measurement time 5.0g of sample Prepare fresh sample in new cup, set on Kim-wipe or similar to check for leaks Measure sample immediately An empirical calibration was built using a set of commercially available certified diesel fuel standards. A summary of the low range calibration is shown here, using a measurement time of 300 sec in helium atmosphere. Element: S Units: ppm Sample I.D. Std Error of Est: 3.5 Correlation: Standard Calculated STD STD STD STD Correlation Plot S Standard REPEATABILITY Low Range To demonstrate repeatability (precision), the select samples were chosen from the set of calibration standards. Each sample was measured in static position for ten repeat analyses using a total analysis time of 300 sec per measurement in helium atmosphere, with typical results shown below. Element: S Units: ppm Sample ID Standard Std Dev % Relative STD STD STD Page 3 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

25 EDXRF APPLICATION NOTE # 1135 REV1 REPRODUCIBILITY Low Range Reproducibility is the longer term reliability over many days, different aliquots of the same sample, different analyzers and different operators. Reproducibility is expected to be X repeatability. To demonstrate reproducibility, two NEX QC analyzers were tested over a 10 day period. A 50 ppm sample was measured on each machine, once or twice a day, for a total of 14 measurements over the 10 day period. ULS measurement protocol was used, and no Standardize drift correction was required. Sample: 50.0 ppm S in Diesel Units: ppm Standard Std Dev % Relative Analyzer Analyzer Green Line: +2.77s 95% Confidence Level Analyzer Purple Line: -2.77s 95% Confidence Level Analyzer Green Line: +2.77s 95% Confidence Level Purple Line: -2.77s 95% Confidence Level Page 4 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)

26 EDXRF APPLICATION NOTE # 1135 REV1 TYPICAL DETECTION LIMITS To determine the Lower Limit of Detection (LLD) using the empirical method, ten repeat analyses of a diesel fuel standards with <0.1 ppm S were measured and the standard deviation calculated. The LLD is then defined as three times the standard deviation. Standard Range in Air Atmosphere Range S 120 sec S 600 sec ppm S 10 ppm 5 ppm Low Range in Helium Atmosphere Range S 300 sec S 600 sec ppm S 5 ppm 3 ppm INTERNATIONAL STANDARD TEST METHODS The Rigaku NEX QC complies with the following international standards test methods for measuring sulfur in crude and petroleum oils. Note that by weight 1 ppm = 1 mg/kg. ASTM D4294 ISO ISO 8754 IP 496 IP336 JIS K ppm 5% mg/kg 100 mg/kg 5% 100 mg/kg 5% 100 mg/kg 5% % FUEL TYPES The performance shown here for diesel is also applicable to the following fuel and oil types when calibrated over similar ranges: Diesel Kerosene Heating oils Jet fuel Naphtha Other middle distillates Residual oil Crude oil Unleaded Gasoline Gasohol Hydraulic oil Mineral oil Biodiesel (see Note 2 ASTM D ) And other similar petroleum products. CONCLUSION The performance shown here demonstrates the ability of the NEX QC to yield excellent results for the measurement of sulfur in diesel fuel in air, without the need for helium purge. Helium can be used to optimize the low sulfur range. Simple, modern touch screen interface allows for reliable and efficient measurement protocols, and performance meets all international norms for the range 100 ppm into % levels of sulfur, and meets ASTM D4294 and ISO for measurements below 100 ppm to the ASTM D4294 scope of PLOQ 16 ppm S. Page 5 Applied Rigaku Technologies, Inc Spectrum Drive, Bldg. 4, Suite 475 Austin, TX USA info@rigakuedxrf.com (+1)