The phrase "a complex mixture of hydrocarbons" is correct and usable in written English.
It can be used in scientific or technical contexts, particularly when discussing chemical compositions or substances.
Example: "Crude oil is primarily composed of a complex mixture of hydrocarbons, which can be refined into various fuels and products."
Alternatives: "a complicated blend of hydrocarbons" or "a diverse combination of hydrocarbons."
Petroleum is a complex mixture of hydrocarbons and non-hydrocarbons of various molecular weights.
Crude oil is a complex mixture of hydrocarbons, consisting of waxes, asphaltenes, resins, aromatics, and naphthenics.
Petroleum is a complex mixture of hydrocarbons and other organic compounds (Hamme et al. 2003).
Petroleum is a complex mixture of hydrocarbons and other organic compounds, including some organometallo-constituents.
It consists of a paraffinic base lubricating oil (a complex mixture of hydrocarbons) and performance enhancing additives.
Bitumen is a complex mixture of hydrocarbons of different families (aromatics, naphthenes, and paraffin among others), oxygen, nitrogen, and sulphur compounds as well as trace metals.
It is composed of a complex mixture of hydrocarbon compounds and a minor amount of inorganic compounds.
During the asphalt heating process in the various stages of hot mix asphalt (HMA) production and paving operations a complex mixture of hydrocarbon aerosols, vapors and gases, generally composed of products of combustion, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), is emitted into the atmosphere.
During the various stages of asphalt paving mixtures production and placement, as a result of binder heating, a complex mixtures of hydrocarbons and volatile organic compounds (VOCs) is released into the atmosphere.
Tar is a complex mixture of condensable hydrocarbons, including, among others, oxygen-containing, 1- to 5-ring aromatic, and complex polyaromatic hydrocarbons.
One of the most prevalent workplace chemical exposures historically and currently confronting the global military and civilian workforce is jet propellant (JP) fuel (e.g., JP4, JP5, JP8, jet A1), a complex mixture of numerous hydrocarbon compounds and additives.
