Grapefruit Seed Extract and Artificial Preservatives

Regarding the October 17th, 2003 Q&A on Grapefruit Seed Extract, could you please provide me with a reliable source for this research? I've been using GSE along with Tocopherols as life extenders for my herbal beauty products as recommended in Susan Miller Cavitch's soap books but if GSE contains artificial preservative chemicals, I'd rather avoid it. I never know where to turn to find honest, accurate research regarding specific "natural" ingredients.

There have been several reports that commercial grapefruit seed extracts contain chemicals such as triclosan, a chlorinated chemical commonly used in personal care products such as deodorants and mouthwash. A Japanese study in 1996 was one of the first to show the presence of triclosan in commercial grapefruit extracts (https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9037863).
In a study published in Pharmazie (https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10399191), six different grapefruit seed extracts were tested for antimicrobial properties. Of the six, five exhibited strong antimicrobial activity. But those five contained the chemicals benzethonium chloride (a preservative), triclosan and methyl parabene, compounds not naturally found in grapefruit. The only extract not found to contain any of these chemicals was also the one that had no microbial effect in this study.