LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
(a)
Type of Measurements: Background [ ]; At contaminated site [ ]; Other [X] Mississippi River
Medium: Surface Water
Results: LAS was detected in 16% of the 323 mainstem samples collected during the
upstream sampling cruises at concentrations ranging from 0.1 to 10.3 µg/L,
and in 15% of the 39 tributary samples at concentrations ranging from 0.1 to
2.8 µg/L. LAS was detected in 21% of the 38 mainstem composite samples
collected during the downstream cruises at concentrations ranging from 0.1
to 2.8 µg/L and was not detected in any of the 16 tributary composite
samples. LAS was detected in 85% of the 34 samples collected from the
Thebes time-series site at concentrations ranging from 0.4 to 28.2 µg/L.
Remarks: The 2,800 km reach of the Mississippi River between Minneapolis and New
Orleans was examined for the occurrence of LAS. River water was sampled
in the summer and fall of 1991 and in the spring of 1992 during upstream and
downstream sampling cruises. LAS was analyzed using solid-phase
extraction and gas chromatography/mass spectrophotometry. The range of
average chain length for all dissolved LAS was 10.2-12.0, with an average of
11.1. The removal of the higher LAS homologues and external isomers
indicates that sorption and biodegradation are the principle processes
affecting dissolved LAS.
Reference: Tabor, C.F. and Barber, L.B. 1996. Fate of linear alkylbenzene sulfonate in
the Mississippi River. Environ. Sci. Technol. 30:161-171.
Reliability: 2 Valid with restrictions
(b)
Type of Measurements: Background [ ]; At contaminated site [ ]; Other [X] Mississippi
Medium: Sediment
Results: LAS was present on all bottom sediments (33 locations) at concentrations
ranging from 0.01 to 20 mg/kg dry matter. It should be noted that all
concentrations were