A purge and trap procedure has been developed for the determination of volatile organic compounds (VOCs) in table-ready foods. VOC analytes are collected on a Vocarb 3000 trap, thermally desorbed, and cryofocused directly on a capillary DB-624 column with GC-MS quantification. Adequate precision was achieved for 45 of the 60 analytes of U S . EPA Method 524.2. Recoveries from 9 food samples fortified with these 45 analytes at 100 ppb and analyzed in duplicate ranged from 75.1 to 117% and from 61.3 to 160% for those fortified at 10 ppb. Average percentage of recovery standard deviation (%RSD) values were 11.3 and 20.4, respectively. Additionally, 234 table-ready foods of the FDA Total Diet Program were analyzed. A total of 77 foods showed residues >50 ppb, 43 >lo0 ppb. Only 47 items contained no residues. Toluene was the most common residue encountered, with residues in 91 foods. Cake doughnuts contained the highest total VOC residues (802 ppb).
Safrole (4-allyl-1,2-methylenedioxybenzene), a natural plant component of the aromatic oil of sassafras root bark, possesses carcinogenic and mutagenic activity. Legal restrictions have been placed on safrole as a food additive. However, sassafras teas continue to be accessible from health food establishments in the United States. Supercritical fluid extraction (SFE) with gas chromatographic-mass spectrometric (GC-MS) determination is utilized in the formulation of a rapid, accurate, and specific method for the determination of safrole and related allylbenzenes in unbrewed sassafras teas. Samples are extracted in a static-dynamic mode with CO2 at 690 bar and 80 degrees C with methanol as an extractor-added modifier. Levels of safrole exceeding 10,000 mg/kg (1.0%) are commonly encountered. Lesser amounts of other allylbenzenes, including eugenol and 4-allyl-1,2-dimethoxybenzene, are also reported. Recoveries of safrole and related compounds from previously extracted tea samples fortified at 100 and 1000 mg/kg ranged from 96 to 101%.
This study determined the effectiveness of copper sulfate (CuSO4) to inhibit fungal growth (caused by Saprolegnia spp.) on largemouth bass (LMB) eggs spawned on/in fiber mats in very high‐alkalinity/‐hardness waters; experiments also determined the toxicity of CuSO4 to LMB fry and juveniles. An untreated control and three CuSO4 concentrations (10, 20, and 40 mg/L) were tested under a flow‐through scenario in the effectiveness experiment. Eggs were treated daily until hatching began. Fungal load at the time of hatch had a total area > 3.0 cm2 in the untreated controls, total area 1.0 to <2.0 cm2 in the 10 and 20 mg/L CuSO4 treatments, and total area > 1.0 cm2 in the 40 mg/L CuSO4 treatments. Fungus samples were identified as Saprolegnia australis. The 24‐hr median lethal concentration (LC50) values on the LMB yolk‐sac and swim‐up fry were 32.0 and 4.6 mg/L CuSO4, respectively; the No Observed Effect Concentrations (NOEC) were 16.0 and 0.125 mg/L CuSO4, respectively. Juvenile LMB were extremely tolerant to CuSO4, and their 24‐hr LC50 value was 185.5 mg/L; the NOEC was 64 mg/L. This study indicates that CuSO4 can be an important resource for hatcheries to control egg fungus, especially in high‐alkalinity/‐hardness waters.
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