EN 15487:2007

Overview

EN 15487:2007 (CEN) specifies a laboratory procedure for the determination of phosphorus (as orthophosphate) in ethanol used as a blending component for petrol. The method uses the ammonium molybdate spectrometric reaction (formation of molybdenum blue) and covers a measurement range of 0.15 mg/L to 1.50 mg/L P. Results are reported in mg/L to the nearest 0.01 mg/L. WARNING: the method involves hazardous acids and reagents; users must implement appropriate safety and regulatory controls.

Key topics and technical requirements

• Principle: Evaporate the ethanol sample, dissolve the dry residue in water, form an antimony phosphomolybdate complex which is reduced by ascorbic acid to a molybdenum blue complex and measured spectrometrically at 880 nm.
• Measurement range: 0.15–1.50 mg/L phosphorus (as orthophosphate).
• Calibration: Multi-point calibration with orthophosphate standards (typical calibration points up to about 1.6 mg/L). Linear regression (absorbance vs mg/L) yields slope (a) and intercept (b) used to calculate sample concentration.
• Reagents: analytical grade reagents including ammonium heptamolybdate (acid molybdate reagent), antimony potassium tartrate, ascorbic acid, sulphuric and hydrochloric acids, sodium hydroxide, and orthophosphate stock/working standards.
• Apparatus: UV/Vis spectrometer capable of 880 nm with 10 mm cells, water bath, evaporating dishes, oven at 105 ± 2 °C, volumetric glassware. Glassware must be phosphate-free and cleaned to avoid contamination.
• Sample handling: Use HDPE containers, follow EN ISO 3170 sampling where applicable, analyse promptly to avoid losses, and avoid phosphate-containing detergents.
• Precision: Repeatability r = 0.03·X + 0.02 mg/L; reproducibility R = 0.09·X + 0.06 mg/L (X = average mg/L).

Applications and users

• Quality control in fuel laboratories, ethanol production plants and blending facilities to verify phosphorus levels in ethanol intended for petrol blending.
• Regulatory compliance testing where phosphorus limits affect engine performance, emission control systems, or fuel certification.
• Analytical and research labs monitoring contamination sources or process control (e.g., tracking phosphorus introduced during production, storage, or handling).
• Refiners and fuel additive manufacturers assessing feedstock compatibility with downstream catalysts and vehicle emission systems.

Related standards and references

• EN ISO 6878: Water quality - Determination of phosphorus - Ammonium molybdate spectrometric method (basis for reagent chemistry).
• EN ISO 3170: Petroleum liquids - Manual sampling (sampling guidance).
• EN ISO 3696: Water for analytical laboratory use.
• EN ISO 4259: Precision data for test methods.
• EU Regulation references (method origins for dry residue procedures).

Keywords: EN 15487:2007, ethanol phosphorus determination, ammonium molybdate spectrometric method, phosphorus in ethanol, ethanol fuel blending, orthophosphate analysis, spectrometry 880 nm.