German coast of the North Sea aboard the 60-m research vessel Heinckk in search ho phosphine. "Even if we do not know yet how phosphine is formed biologically," Gassmann explains, "we are able to account for the final product phosphine without any doubts in places where methanogenic conditions prevail." Gassmann is one of only two marine chemists at Biological Institute Helgoland, the oldest marine research institute in Germany. Founded in 1892 on the rocky island of Helgoland, it was a federal institute until last year. Since January it has been organized under the umbrella of the Foundation Alfred-Wegener-Institute for Polar and Marine Research in Bremerhaven, a member of the Helmholz Association of German Research Centers. The change in organization means that Gassmann and his colleagues in Hamburg leave for Bremerhaven this month. An easy task thanks to his mobile lab equipment. The Biological Institute Helgoland runs two island stations—the Marine Station on Helgoland and the Waddensea Station on the island of Sylt, which is located at the seabound border of the mudflats off the northern coast of Germany. As a marine chemist Gassmann originally was interested in phosphate cycles of marine
ecosystems. Ten years ago phosphine caught his attention. "Phosphine has two faces," Gassmann explains. "Technically fabricated, it has broad application in corn storage as an insecticide and fungicide as well as in chip fabrication as a doping gas to incorporate foreign atoms into semiconductor materials. On the other hand, it is a highly dangerous substance." Concentrations as low as 20 ng/kg are considered toxic. Moreover, it is carcinogenic and leads to leukemia. Even subtoxic concentrations can accumulate in the body. In 1993, Gassmann began collaborating with Dieter Glindemann of the University of Leipzig, who succeeded in modifying Gassmann's apparatus so that phosphine could be analyzed in the air above the sea surface at the attogram level. This was imporrant because of the compound's high toxicity. Aboard the Heincke aii ramples of 50500 mL are pressed through an adsorption cartridge, removing hydrogen sulfide, carbon dioxide, and water. After passing through the cartridge the eluent is cryofocused for adsorption of phosphine and high-molecular-weight hydrocarbons. The trapped sample is then focused again by thermodesorption into another trapping device cooled to liquid nitrogen temperatures. Sudden thermodesorption is used to push phosphine and very volatile hydrocar-
bons into a capillary where the phosphine is separated from the light hydrocarbons. Quantitative analysis is performed with a thermionic detector. During their cruises off the German coast, Gassmann and Glindemann found daily mean phosphine concentrations of 50 pg/m2 and peaks of 800 pg/m2 at night. In summer, when air temperatures reach 20 °C, and at low tide, when vast areas of the Waddensea are laying dry, 15 ug of phosphine are gassing out from one square meter of the mud flats during this tide cycle—750 times more than the toxic level. "Since the middle of the last century, scientists [have] pointed out that the occurrence of cancer and cancer lethality is in correlation with certain geophysical factors," Gassmann remarks. "In the vicinity of humid grounds and in areas often flooded by rivers, the risk for cancer is increased." What the findings of Gassmann and Glindemann may mean to people living at the coasts has yet to be investigated. In Germany thefindingsof the marine chemists have added a new view to environmental discussions. Nuclear power plants have been blamed for increased occurrences of childhood leukemia, but most of the German plants are located in humid areas near river banks. Hanns-J. Neubert
NEWS FROM ANALYTICA ’98 Celia Henry and Veronika Meyer report from Munich, Germany Now even 1-cm columns have been suc"Quick-and-dirty" cessfully used. The sample volume in this pesticide analysis case is 4 mL, and a run takes only 4 min Udo Brinkman of the Free University of Am- plus 1 min for regeneration. Linearity and sterdam (The Netherlands) now uses very limit of detection (10-100 ng/L) are compashort HPLC columns for pesticide analysis of rable to more conventional trace analytical river water. Until recently, sample preparamethods for pesticides in water. tion involved solid-phase extraction directly coupled to a 25-cm column. However, 95% oo On-site analysis of more of the samples from the Rhine River and its tributaries are pesticide-free. "For contaminated soils these samples, it is not necessary to use Bringing the analytical equipment to the such a sophisticated analytical system, so we field can be more advantageous than bringtried [to see] if we could do it in a simpler ing the samples to the laboratory. Gerhard way," Brinkman explained. Zwickof Ansyco (Germany) described how The new approach works. A 15-mL wa- it is possible to obtain high-quality data of contaminated soils in the field. ter sample is pumped through a 2-cm reversed-phase column that can separate He used a battery-powered, hand-held 16 pesticides with a 13-min gradient. Detec- photoionization detector (PID) for the nontion is done by MS/MS. Although the colselective determination of volatile organic umn lasts for only 30-40 injections before it compounds; an isothermal gas chromatomust be replaced, this approach is very graph with a 30-m wide-bore column for attractive, says Brinkman. the selective analysis of the same com-
pounds; and a portable IR spectrometer for the determination of nonvolatile hydrocarbons after their extractionfromthe soil samples with R113 (a halogenated solvent allowed for analytical purposes by the Montreal Protocol). PID and GC analyses correlated well at the site of investigation, but the PID is fast and much simpler to handle. The IR analyses did not correlate with those of the other techniques, which is not surprising because the techniques are usually used for other classes of compounds. On-site analysis has the advantage that the whole analytical process from sampling to data evaluation and interpretation is done by the same person The sampling strategy (both on the surface and at a depth down to several meters) can be adapted immediately as indicated by the results The instruments are easy to handle and rugged; Zwick and his colleagues regret that the on-site at> proach is not yet widelv accented by the analytical communitv
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