Sulfur that is present in feedstock can also be found in the finished biodiesel. To ensure biodiesel conforms to the ultra-low sulfur diesel (ULSD) standard of 15ppm maximum (10ppm maximum in Europe), it is important to manage the sulfur concentration in the feedstock. If not properly treated, sulfur can transfer to the finished fuel. This technique involves preparation of the sample with kerosene or a kerosene-substitute followed by ICP-OES analysis.