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Field laboratories of the U.S. Food and Drug Administration collected and tested 11,312 import and 768 domestic seafood samples over a 9-year period (1990 to 1998) for the presence of Salmonella. The overall incidence of Salmonella was 7.2% for import and 1.3% for domestic seafood. Nearly 10% of import and 2.8% of domestic raw seafood were positive for Salmonella. The overall incidence of Salmonella in ready-to-eat seafood and shellfish eaten raw was 0.47% for domestic--one shucked oyster and one shark cartilage powder. The incidence in the 2,734 ready-to-eat import seafood was 2.6%--cooked shrimp, shellfish or fish paste, smoked fish, salted/dried fish, and caviar. The incidence in import shellfish consumed raw was 1% in oyster, 3.4% in clams, and 0% in mussels. The incidence in raw, import fish was 12.2%. Distribution of Salmonella in seafood on a regional basis indicated the incidence to be highest in central Pacific and Africa and lowest in Europe/Russia and North America (12% versus 1.6%). Data on a country basis indicated Vietnam to have the highest (30%) and Republic of Korea the lowest (0.7%). While the most frequent serotypes in import seafood were Salmonella Weltevreden (1st), Salmonella Senftenberg (2nd), Salmonella Lexington, and Salmonella Paratyphi-B (3rd, equal numbers for each serotype), the top 20 list included Salmonella enteritidis (5th), Salmonella Newport (6th), Salmonella Thompson (7th), Salmonella typhimurium (12th), and Salmonella anatum (13th), commonly involved in foodborne illness in the United States. Because the incidence in the present study is based on only a small fraction of the seafood imported into the United States, efforts should be directed toward implementation of hazard analysis and critical control points to reduce the incidence of Salmonella in seafood without relying on testing for Salmonella.

The frequency of occurrence of Listeria spp., Salmonella spp., and Clostridium botulinum is samples of smoked finfish and smoked shellfish was analyzed over a 5-year period. Listeria monocytogenes were isolated from 14% of 1,080 samples. For those samples where the smoke process was known, the incidence of L. monocytogenes was higher in cold-smoked than hot-smoked products (51 of 240 cold-smoked compared to 19 of 215 hot-smoked products). Listeria species other than L. monocytogenes were also detected (in 7.2% of cold-smoked and 3.8% of hot-smoked products). The time and temperature smoke processing guidelines are reviewed for a few state authorities. L. monocytogenes was isolated from 15.2% of the 559 samples of foreign origin. There were four countries for which more than 70 samples were analyzed: Canada, Norway, the Philippines, and the United Kingdom. The occurrence of L. monocytogenes in samples from these four countries was 14.3%, 23.7%, 0%, and 16.1%, respectively. The 521 samples originating in the United States were processed by 194 plants. Thirty-seven plants in 13 states produced contaminated product. Salmonella species were isolated from 5 (3.2%) of 156 samples tested for this organism. All positive samples were of foreign origin (4 from the Philippines and 1 from the United Kingdom). No C. botulinum spores were detected in any of the 201 vacuum-packed samples tested for this organism.

The effect of mobile phase pH on the retention characteristics of eleven proteins was examined in hydrophobic interaction chromatography (HIC) on a SynChropak propyl stationary phase. Selectivity was shown to change with eluent pH. The effect of the displacing salt on the separation of proteins on a weakly hydrophobic weak-anion-exchange chromatography (AEC) packing was examined. Some differences in selectivity were observed when sodium sulfate was used as the displacing salt, compared to that observed with sodium chloride in the eluent. It was demonstrated that these AEC packings exhibited both electrostatic and hydrophobic properties, depending upon the type and concentration of salt used in the mobile phase. The addition of 20% ethylene glycol to the mobile phase was shown to reduce the hydrophobic interactions. The application of weakly hydrophobic weak-cation-exchange packings to HIC of proteins was demonstrated. Elution of such columns with descending sodium sulfate gradients was found to provide a selectivity different from that observed with a propyl stationary phase. Manipulation of mobile phases was shown to provide useful selectivity as a result of the combination of electrostatic and hydrophobic contributions to the separation process.

A convenient high-performance liquid chromatographic method for the quantitative determination of cyclobenzaprine hydrochloride in tablets is described. Samples were dissolved in 0.05 N sulfuric acid and diluted with methanol. The cyclobenzaprine hydrochloride was chromatographed using an octylsilane column and the eluent acetonitrile-0.6% dibasic potassium phosphate aqueous buffer (pH 3.0) (75:25) at a flow rate of 1.5 ml/min. Naphazoline hydrochloride was used as an internal standard. The UV detector response at 254 nm was linear for cyclobenzaprine hydrochloride in the 0.005-0.03 mg/ml range under conditions of the analysis.