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Optimization of PAH determination in samples of recovered bituminous mixtures

Feb 11, 2020

In some national legislation criteria where the asphalt mixture is a by-product or ceases to be waste, the issue of determination of polycyclic aromatic hydrocarbons (PAH) in asphalt mixtures has become an intensively discussed and developed topic.

In our ALS laboratories, we continuously develop new methods and optimize them so that we can always offer our customers efficient, economical and above all quality services. For the analytical purposes of determination of polycyclic aromatic hydrocarbons in asphalt mixtures, the laboratory experts immediately prepared an "analytical combination" involving both specific homogenization and sample preparation, and subsequent determination of PAH content.

Ideal PAH determination? Fast, reliable, accurate

The ALS laboratory, thanks to its many years of experience in the field of determination of PAH in asphalt, has a proven method for determination of PAH in this type of material. Due to the orderly growth in the number of asphalt samples for this type of PAH analysis, our organic laboratory department prepared a significant increase in capacities for this type of determination. We have invested in new instruments and equipment (another mill suitable for crushing asphalt samples, several gas chromatographs) and increased the number of laboratory employees in the relevant departments.

In addition, laboratory experts have worked intensively to enhance the method of a PAH-targeted extraction and accelerated PAH determination in asphalt, while keeping high quality standards. In a short time, they have made significant progress and ALS is proud to introduce an optimized method for determining polycyclic aromatic hydrocarbons in asphalt mixtures. This new method meets the requirements of our customers for the ability to process large quantities of samples in the required time.

New PAH method in a nutshell:

• Accredited method optimal for determination of PAH in asphalt

• Verified method by comparing the results from the original method by testing several sets of real samples

• Allows processing up to twice more samples compared to the original method

• Higher sample weight for extraction even better resolves sample homogeneity and increases precision

• Cryogenic grinding and crushing of the sample especially suitable for asphalt materials for both recovered asphalt mixture and test boreholes

• The output consists in the sum of 16 polycyclic aromatic hydrocarbons, including report of benzo(a)pyrene

• Limits of determination comply with most of legislative requirements on criteria where the asphalt mixture is a by-product or ceases to be waste or even where the asphalt mixture is considered as waste.

If necessary, quicker delivery of results for the content of PAH and benzo (a) pyrene may be carried out under the terms of the offer and ALS Czech Republic General Terms and Conditions.

If you have a request for PAH analysis, feel free to contact us at +420 226 226 228 or email us at

Technical specifications of the optimized laboratory method under code S-PAH-ASPH-130

Recommended sample weight is 500 g, possibly according to the size of the test bore.

Parameter Limit of Quantification Unit
Dry matter at 105 °C 0,1 %
sum 16 PAU 3,2 mg/kg dry matter
naftalen 0,2 mg/kg
acenaftylen 0,2 mg/kg
acenaften 0,2 mg/kg
fluoren 0,2 mg/kg
fenantren 0,2 mg/kg
antracen 0,2 mg/kg
fluoranten 0,2 mg/kg
pyren 0,2 mg/kg
benz(a)anthracen 0,2 mg/kg
chrysen 0,2 mg/kg
benzo(b)fluoranten 0,2 mg/kg
benzo(k)fluoranten 0,2 mg/kg
benzo(a)pyren 0,2 mg/kg
indeno(1,2,3-cd)pyren 0,2 mg/kg
benzo(g,h,i)perylen 0,2 mg/kg
dibenz(a,h)antracen 0,2 mg/kg