The objectives of this paper are (i) to present reliable methods of quantification of both hydrocarbons and metals in dissolved and particulate urban runoff samples as well as atmospheric deposits, (ii) to emphasise on the validation procedure of these methods by using replicates, available certified samples or standard mixtures. NIST 1648 (urban particulate matter), BCR 144 R and 146 R (trace elements in sewage sludge from domestic and industrial origin, respectively), NIST 1643c (trace elements in water), SPS-WW1 and SPS-SW2 (waste and surface waters, respectively), were used with success for validating metal extraction and analysis procedures. In the absence of certified urban runoff sample for particulate or dissolved aliphatic hydrocarbons, NIST SRM 1941a was used as noncertified particulate sample (marine sediment certified only for aromatic hydrocarbons) and Florida TPH mix (NSI Environmental Solutions) as a mixture of 17 dissolved aliphatic hydrocarbons from C 10 to C 40. Such validation procedures enable a better discrimination between sample heterogeneity and determination precision.