简介:2.1 A measured volume or weight of sample (approximately 1 L for liquids, 2 to 30 g for
solids) is extracted using the appropriate matrix-specific sample extraction technique.
2.1.1 Aqueous samples may be extracted at 简介:2.1 A measured volume or weight of sample (approximately 1 L for liquids, 2 to 30 g for
solids) is extracted using the appropriate matrix-specific sample extraction technique.
2.1.1 Aqueous samples may be extracted at neutral pH with methylene chloride
using either Method 3510 (separatory funnel), Method 3520 (continuous liquid-liquid
extractor), Method 3535 (solid-phase extraction), or other appropriate technique.
2.1.2 Solid samples may be extracted with hexane-acetone (1:1) or methylene
chloride-acetone (1:1) using Method 3540 (Soxhlet), Method 3541 (automated Soxhlet),
Method 3545 (pressurized fluid extraction), Method 3546 (microwave extraction), Method
3550 (ultrasonic extraction), Method 3562 (supercritical fluid extraction), or other appropriate
technique.
2.2 A variety of cleanup steps may be applied to the extract, depending on the nature of
the matrix interferences and the target analytes. Suggested cleanups include alumina (Method
3610), Florisil (Method 3620), silica gel (Method 3630), gel permeation chromatography (Method
3640), and sulfur (Method 3660).
2.3 After cleanup, the extract is analyzed by injecting a measured aliquot into a gas
chromatograph with either a narrow-bore or wide-bore fused-silica capillary column, and either an
electron capture detector (GC/ECD) or an electrolytic conductivity detector (GC/ELCD).详细>