Standard Operation Procedure for using gaiasafe passive collectors (PC)
gaiasafe gmbh, Stadtwaldstr. 45a, D-35037 Marburg
Dr. Rainer Haas
General description of passive collectors:
Passive collectors are impregnated fibre materials (paper) that are covered to prevent mechanically destruction. PC are able to absorb inorganic chemicals (all kinds of heavy metals except iron, half metals like arsenic (As), stibium (Sb) and selenium (Se), other metals like aluminium and chlorine). Absorption capacity is about 9% of total paper weight.
PC are able to absorb organic compounds, polar compounds and unpolar compounds like phenols, carbonic acids, aromatic compounds, nitro aromatic compounds, trichloroethylene etc.. Absorption capacity for organic compounds is about 5% of total paper weight.
How to use gaiasafe PC:
PC can be used in surface water, waste water chanels and well water stations. Normal design of PC is for using in well water, sometimes for surface and waste water additional a protection against mechanical destruction is necessary.
PC were put into water and fixed by a line. The collection time is about four weeks. Reductive conditions (H2S), bacteria etc. do not destroy the PC. After using the PC is recovered from water, dried by room temperature and stored in paper and additional in a PE cover. If it is possible, PC after using and drying shell be stored dry, dark and cold. The absorbed compounds are stable at the PC. Part of the used PC can be stored for future analysis. Chemical analysis should be done as soon as possible.
Analysis in laboratory:
In principle the sample extraction procedure for PC is the same as for soil samples. Only 0.2 to 0.5 g of collector material must be used for one extraction.
For inorganic substances 0.2 g PC material is extracted with 5 ml conc. hydrochloric acid for 15 min in ultrasonic bath. After four hours the mixture is filtered. Fe(OH)3 is extracted too. If analysis is done by atomic absorption spectrometry (AAS), no problems are present.
For organic compounds 0.5 g PC material is extracted with 10 ml methanol for 15 min in ultrasonic bath and then stored four hours by room temperature. After this time the extract is filtered.
Instead of ultrasonic bath in principle soxhlet extraction is possible too. Instead of methanol, depending on the compounds, other extraction solvents can be used too, like toluene or dichloromethane.
In any case, sample preparation procedure must be described in report. The analysis of the extract is done like usual with the laboratory methods. The obtained results are presented in mg/g PC.