Correction Anal. Chem. 1997, 69, 801
Coupled Subcritical Water Extraction with Solid-Phase Microextraction for Determining Semivolatile Organics in Environmental Solids Kimberly J. Hageman, Laurent Mazeas, Carol B. Grabanski, David J. Miller, and Steven B. Hawthorne* (Anal. Chem. 1996, 68, 3892-3898)
We wish to clarify the assembly of the extraction cell and emphasize a related safety issue. The cell was constructed with a stainless steel pipe fitted with threaded (npt) caps. One end was capped, the sample was added, and then water was added to a volume of 3.5 mL including 2.5 mL for the pipe fitting and an additional 1.0 mL for the end cap. The filled cell was then sealed with a second cap, thus creating a 1-mL headspace (for a total cell volume of 4.5 mL). This headspace is absolutely required so that the maximum pressure does not exceed the steam/water equilibrium pressure. Although it was not possible to fill the described cell completely (and thus the pressure safety margin was maintained by the steam/water equilibrium), this procedure should NEVER be used with a cell design that does not include a suitable headspace volume because heating a completely filled cell could result in pressures exceeding several thousand bar.1 (0) Haar, L.; Gallagher, J. S.; Kell, G. S. National Bureau of Standards/ National Research Council Steam Tables; Hemisphere Publishing Corp.: Bristol, PA, 1984.
AC9613951
S0003-2700(96)01395-9 CCC: $14.00
© 1997 American Chemical Society
Analytical Chemistry, Vol. 69, No. 4, February 15, 1997 801
