Fundamentals of Sample Preparation for Environmental Analysis - Fundamentals of Environmental Sampling and Analysis - page 181

Sulfur Clean-up Elemental sulfur is a common contaminant that can be easily
shown on chromatography as a semivolatile. It is removed by the agitation with
powdered Cu, mercury metal, or tetrabutyl-ammonium sulfite [CH 3 (CH 2 ) 3 ] 4 NHSO 4 .

Sulfuric Acid/Permanganate Clean-up This method uses concentrated
H 2 SO 4 and 5% KMnO 4 . It is a very rigorous clean-up that will remove most
interference except PCBs, chlorinated benzenes, and chlorinated naphthalenes. This
method cannot be used to clean-up extracts for other target analytes, as it will destroy
most organic chemicals including several pesticides. A few chlorinated hydrocarbons
will survive.

7.4.2 Recommended Clean-up Method
for Selected Compounds

The clean-up methods specified in the EPA SW-846 is summarized in Table 7.2. It is
noted that most of the soil, sediment, and waste samples require clean-up. Four
major mechanisms are also listed in this table, i.e., adsorption, size separation,
partitioning, and oxidation-reduction reaction.

Table 7.2 Selection of cleanup methods and their environmental applications

Cleanup type

Purpose of cleanup (mechanism) Method no.

Analysis of phthalate esters (neutral alumina) Alumina (adsorption) EPA 3610

and nitrosamines (basic alumina)
Separation of petroleum wastes into aliphatic,

Alumina (adsorption) EPA 3611

aromatic, and polar fractions (neutral alumina)
Analysis of phthalate esters, nitrosamines, Florisil (adsorption) EPA 3620

organochlorine pesticides, PCBs, chlorinated
hydrocarbons, organophosphorus pesticides
Analysis of PAHs, PCBs, and derivatized phenol Silica gel (adsorption) EPA 3630

Analysis of phenols, phthalate esters, nitrosamines, Gel-permeation EPA 3640

organochlorine pesticides, PCBs, nitroaromatics, (size-separation)

cyclic ketones, PAHs, chlorinated hydrocarbons,
organophosphorus pesticides, priority pollutant
SVOCs
Analysis of phenols, priority pollutant semivolatile

Acid-base partition EPA 3650

(partitioning)

Analysis of organochlorine pesticides, PCBs, Sulfur clean-up EPA 3660

priority pollutant SVOCs (oxidation-reduction)

Analysis of PCBs, chlorinated benzenes and H 2 SO 4 -permanganate EPA 3665

chlorinated naphthalenes (oxidation-reduction)