Joan T. Bursey

Analysis of selected pesticides by high-performance liquid chromatography—mass spectrometry

Abstract A Finnigan 4500 mass spectrometer was modified to perform direct liquid introduction high-performance liquid chromatography—mass spectrometry (DLI-HPLCMS). The HPLCMS analysis of some 25 pesticides, including carbamates, chlorinated carboxylic acids and methyl ureas is described. The qualitative appearance of the spectra as well as detection limits are presented for both positive and negative ion detection. In most cases DLI-HPLCMS, using an 1:100 split, provided molecular weight information with sub-microgram detection limits and greatly increased specificity over HPLC detection.

Analysis of candidate anticancer drugs by thermospray high-performance liquid chromatography—mass spectrometry

Thermospray high-performance liquid chromatography-mass spectrometry was used to confirm the identity of five bulk anticancer drugs, and in some cases, to identify drug impurities. Analysis resulted in both molecular weight and structural (fragment ions) information obtained from the full scan spectra of as little as 50 ng of each drug. The technique was also used to evaluate the chromatographic specificity of corresponding ultraviolet or refractive index high-performance liquid chromatographic detection in the presence of drug degradation products.

Sampling and Analysis Experiments for Improved Characterization of Products of Incomplete Combustion

Laboratory and field experiments were conducted to evaluate the volatile organic sampling train (VOST) methodology for the sampling and analysis of products of incomplete combustion (PICs). A pilot-scale incinerator was used to incinerate several volatile chlorinated organic compounds which were known to produce PICs. Approximately 300 ppm of 1,2-dichloroethane, 1,1,1-trichloroethane, and trichloroethene were individually incinerated at 700°C. Standard VOST sampling apparatus was used to collect samples for determinations of precision and for distributive volume-studies. A series of experiments was conducted to establish whether PICs were being formed at concentration levels which could be measured by the VOST methodology. Samples were collected at 1 L/ min for 20 min with standard pairs of Tenax-Tenax/charcoal cartridges. The major PICs found were vinyl chloride from 1,2-dichloroethane, 1,1-dlchloroethene from 1,1,1-trichloroethane, and carbon tetrachloride from trichloroethene. Chloromethane was also fo...

Replacement of Charcoal Sorbent in the Sampling of Volatile Organics from Stationary Sources

Abstract U.S. Environmental Protection Agency Method 0030 for sampling volatile organics from stationary sources (VOST) specifies the use of petroleum-based charcoal in the second sorbent tube. Charcoal has proven to be a marginal performer as a sampling sorbent, partly due to inconsistency in analyte recovery. In addition, commercial availability of petroleum charcoal for VOST tubes has been variable. Lack of data on comparability and variability of charcoals for VOST application has created uncertainty when other charcoals are substituted. Five potential sorbent replacements for charcoal in Method 0030 were evaluated along with a reference charcoal. Two of the sorbents tested. Ambersorb XE-340 and Tenax GR, did not perform well enough to qualify as replacements. Three candidates, Anasorb 747, Carbosieve S-III and Kureha Beaded Activated Charcoal, performed adequately, and produced statistically equivalent results. Because Anasorb 747 exhibited an excellent combination of performance, availability, and c...