PASSIVE SAMPLING
Passive sampling in water offers several advantages over conventional
sampling. The sampler is deployed for extended periods of time (often
days or weeks), enriching trace analytes to facilitate their detection
and quantification. The results obtained are concentrations averaged
over the sampling time. ALS offers passive samplers for non-polar
organic compounds (e.g., PAH, PCB, dioxins), polar organic compounds
(e.g., water soluble pesticides) and metals.
PS Organic
PS Organic is our passive sampling system for non-polar organic compounds, such as
PAHs, PCBs and dioxins. The sampler consists of a stainless steel canister that holds one
or two membranes, mounted in so-called spiders. Canisters and spiders can be hired or
purchased. Alternatively, a smaller and simpler disposable sampler, which holds one or
two shorter membranes can be used. The membrane contains a lipid that easily absorbs
hydrophobic substances. The length of the sampling period is variable, but is often about
one month. During this time, organic pollutants in dissolved or gas phase diffuse through
the membrane and accumulate in the lipid. This uptake mimics the accumulation of
organic pollutants in, for example, fish. The organic compounds are then extracted from
the membrane for subsequent chemical analysis by conventional methods. From the
analytical result, the concentrations in the ambient water can be calculated.
Concentrations of lipid-soluble substances in water are often so low that direct chemical
analysis is difficult, but the passive sampler provides substantial preconcentration and
thus enables more reliable analyses. Due to the large capacity of the lipid, a relatively
long time (often >1 month) will elapse before the sampler is saturated, i.e., before a
state of equilibrium has been attained between sampler and water. This means that even
polluted waters can be sampled using PS Organic.
Analyses for PS Organic
Analytical package
Polycyclic aromatic hydrocarbons (PAH)
Polychlorinated biphenyls (PCB)
Organochlorinated pesticides
Dioxins and furans (PCDD/F)
Coplanar PCBs and indicator PCBs
Brominated flame retardants (PBDE)
Organotin compounds
LOQs depend on sampling times.
Other analyses may be possible. Please contact your local sales representative for further information.
PS Metal
PS Metal is used to sample metals in situ in water, soil and sediment. The simple
plastic sampler contains a filter, a hydrogel, and an ion exchange resin. Metal ions in
water diffuse through the filter and the gel, and finally accumulate in the ion exchange
resin. The longer the sampling time, the larger the amounts of ions accumulated. In
uncontaminated water, the equipment can be left in place for several months. The ions
are then eluted from the resin with acid, and can be determined by ICP-AES or ICP-MS.
If the water temperature and the exposure time are known, the concentration of each
metal in the water can easily be calculated.
Analyses for PS Metal
Analytical package
Basic metal package
(Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, U, Zn)
Extended metal package
(Ag, Al, Ba, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Gd, Ho, La, Lu, Mg, Mn, Nd, Ni, Pb, Pr, Sm, Sr, Tb,
Tm, U, Yb, Zn)
LOQs depend on sampling times. Please contact your local sales representative for further information.
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Product catalogue Water
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