Since the early 1980s, there has been a steady increase in the use of nonvolatile fluorinated organic compounds for a variety of industrial and commercial applications. The industrial use of these relatively stable compounds has initiated debate over the fate of fluorochemicals in the environment and, ultimately, the bioavailability of these compounds. In this manuscript, we present quantitative results from a study of 65 human sera samples purchased from biological supply companies that provide characterization of specific organic fluorochemicals present in the sera of nonindustrially exposed humans. Summed together, the compound-specific characterization data reported here agree closely with levels of nonspeciated organic fluorine that were originally reported to be present in sera in 1970. The compound-specific method for the extraction of extremely low levels of several commercial organic fluorochemicals from sera and liver with quantitative detection by negative ion electrospray tandem mass spectrometry described represents a robust, previously undescribed approach to quantifying specific organic fluorochemicals in biological matrices.

Although there is evidence of widespread distribution of organic fluorochemicals such as perfluorooctane sulfonate and perfluorooctanoate, in the environment, the versatility of these compounds in industrial and commercial applications complicates characterization of pathways into the environment. A solid-phase extraction method coupled with HPLC-negative-ion electrospray tandem mass spectrometry was developed to quantitatively measure trace levels of organic fluorochemicals in drinking water and surface water. Using this method, certain fluorochemicals can be quantitatively measured in water samples down to 25 ppt, a level well below calculated drinking water advisory levels. To assess fluorochemical distribution in a localized geography and to ascertain whether fluorochemical manufacturing facilities contribute to environmental levels of fluorochemicals, 40 water samples were collected on an 80-mi stretch of the Tennessee River, near a fluorochemical manufacturing site in Decatur, AL. Low levels (ppt) of perfluorooctane sulfonate were determined throughout the stretch of river sampled. Concentrations of the measured fluorochemicals increased downstream of the fluorochemical manufacturing facility, indicating that effluent from manufacturing is one likely source of organic fluorochemicals into the river.

Methods are described for the clean, efficient separation of large quantities of elements deposited at the mercury cathode from those which are not affected (aluminum, alkaline earths, alkali metals, etc.); these methods are based on the use of a previously described unitized mercury cathode apparatus (4) suitable for industrial analytical applications.Procedures are given for the removal of 0.5to 5.0gram quantities of easily removable metals such as

A model 18 Perkin-Elmer flame photometer is useful for the rapid determination of sodium and potassium in solutions of restricted composition, but its direct use is subject to serious errors which are variously produced by certain common substances possibly present in the test solution.Very large negative errors are caused by appreciable concentrations of phosphate, borate, and oxalate ions, and by very high concentrations of mineral acids; large errors are produced by ammonium, alkali, alkaline earth, and other cations, particularly when present in high concentrations.

A convenient dual unitized apparatus is described for rapid electrolytic removal of heavy metals from solutions of reactive elements, such as alkali metals, alkaline earth metals, and aluminum, using a mercury ca thode of new design. The apparatus consists of a self-contained immersion electrode assembly coupled to a high-capacity Tungar rectifier and a suitable control panel. It allows convenient, efficient use.with high current densities, permits easy washing of the electrode assembly without re-solu-THE removal of interfering metals prior to the determination of other elements offers numerous difficulties. If precipitation of the undesirable elements is to be employed, it is necessary to anticipate occlusion and to choose a suitable method or reagent that will not introduce interfering elements. It is often difficult to obtain reagents sufficiently free from the element to be determined; sometimes, subsequent removal of excess reagent offers additional difficulties. By contrast, electrolysis with the mercury cathode ( 7) eliminates virtually all these problems when applicable. With suitable apparatus it is generally possible to perform the electrolysis in a fraction of the time required for most chemical separations, leaving a dilute acid solution almost completely free of metallic elements.According to Lundell and Hoffman (8), the metals which-are quantitatively deposited in the mercury cathode are: chromium, iron, cobalt, nickel, copper, zinc, gallium, germanium, molybdenum, rhodium, palladium, silver, cadmium, iridium, tin, rhenium, indium, platinum, gold, mercury, thallium, bismuth, and polonium. Other elements which are completely removed from solution but not quantitatively deposited in the mercury are osmium, which is partially volatilized as the tetroxide at the anode, selenium and tellurium, which are reduced to the elemental state but remain unamalgamated, load, which may be partially deposited on the anode, and arsenic,