Standard Practice for Sampling, Storage, and Handling of Hydrocarbons for Mercury Analysis

Importancia y uso:

5.1 This practice is intended for use in sampling liquid hydrocarbons including crude oils, condensates, refinery process intermediates, and refined products. Generally these samples are expected to contain mercury from the parts per billion (10^–9 mass) to parts per million (10^–6 mass) range.

5.2 This practice is not intended for use when sampling aqueous systems where the concentrations of mercury are often in the parts per trillion (10^–12 mass) range. These samples are often better addressed by using the rigorously clean techniques from the EPA Method 1669 “clean hands, dirty hands” sampling procedures.

5.3 This practice is not intended for use for liquefied samples, for which special containers may be required for pressurized samples.

5.4 This practice is only suitable for stabilized samples which remain 100 % liquid at ambient conditions. For samples that on depressurization lose some of the light hydrocarbon ends it is important to note that elemental mercury may be lost during sampling. Sampling modules which inject unstabilized liquid hydrocarbons close to process conditions directly to the mercury analyzer can be used to overcome this issue.

5.5 Based on this practice, two Test Methods (D7622 and D7623) are available for determination of mercury in crude oil, based on cold vapor atomic absorption technique.

5.6 In some refined streams and in tank samples free water may be present. Process streams that are water saturated may condense water as the sample cools from process temperature to ambient temperature. Ionic mercury species are water soluble and these water droplets may contain mercury or adsorb mercury over time.

5.7 The presence of mercury during crude oil production, transport, and refining can be an environmental and industrial hygiene concern.

Subcomité:

D02.03

Referida por:

D7622-20, D8056-24, D7623-20, D7455-24, D7623-20, D7622-20, D7623-20, D7622-20

Volúmen:

05.04

Número ICS:

71.040.40 (Chemical analysis)

Palabras clave:

handling; mercury; mercury analysis; sampling; storage;