摘要:

AbstractBetween November 1985 and October 1986 20 water samples were taken off at Rostock‐Warnemünde and analyzed by optimized electroanalytical and atomic absorption spectroscopical (AAS) methods on lead, cadmium, copper and zinc. Determinations by AAS were carried out following extraction of those metals as APDC/DDDC chelate complexes with freon and their back‐extraction into diluted nitric acid. Electroanalytical determinations were performed by stripping voltammetry (IV) with mercury film electrodes on glassy carbon together with differential pulse polarographic (DP) recording with (DPIV/UV) and without preceding UV‐photolytic treatment (DPIV) of the samples. The observed concentrations increased in the order DPIV – DPIV/UV – AAS. In the order Cd – Pb – Zn – Cu those fractions of metals increase which only become available for the electroanalysis following mineralization of natural organi

ISSN:0323-4320    

DOI:10.1002/aheh.19880160502

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19880160503

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractRecently the method of flotation is used as a simple step within a number of procedures of chemical analysis for enrichment of waters or industrial lyes to be investigated by ions. By the example of tin analysis all the possible variants are compared with regard to their efficiency. The advantages result from the using conventional methods of chemical analysis in connection with coprecipitation of traces and their flotation at trace levels of ng/ml. The flotation is a fast method of enrichment, it is easily to handle and sufficiently exact. As a proof example the chemical analysis of Sn, Au and Ag is described.

ISSN:0323-4320    

DOI:10.1002/aheh.19880160504

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19880160505

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractA Specord M 40 device with the Date Handling 1 computer cassette was used for the derivative‐spectroscopie determination of lignosulphonic acid. Because of the higher sensitivity and the better evaluable peaks, the 2nd derivation of the five possible derivations was used. The analysis method described in detail was tested with test substances on a surface water which was polluted with waste‐products from the pulp industry. With the stated device parameters, the lignosulphonic acid up to 2 mg/l can be determined in the presence of humic acids and chlorolignosulphonic acids. In weakly polluted waters, as groundwaters and shore filtrates. still lignosulphonic acid concentrations of 0.1 mg/l can be detected after an adequate enrichm

ISSN:0323-4320    

DOI:10.1002/aheh.19880160506

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19880160507

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractA BASIC Program for divisive clustering is proposed. The algorithm of Macnaughton‐Smith is used to improve the variance criterion. No distance matrix is needed and in this way large numbers of objects can be handled. An application of the program to the classification of 20 european brandies is demonstrated. The listing of the program is given in the appendi

ISSN:0323-4320    

DOI:10.1002/aheh.19880160508

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19880160509

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe seasonal fluctuation, biomass and productivity of epipelic algae in the shallow Neusiedlersee (Austria) were studied from 1981 to 1983. The seasonality of epipelic algae, dominated by diatoms (70 % of the total population), showed a pattern of variable winter growth coupled with a moderate spring and summer maximum. The number of mud dwelling species remained the same as shown in previous studies (LOUB; HUSTEDT1959a, b), but only two of them, namelySurirella peisonis PantocsekandCampylodiscus clypeusEhr., were not abundant. The Diversity Index (H′) varied between 1.0 and 2.86. Specific Biovolumen (x= 47 · 1012μm3m2) and potential of production (x= 22.75 mg/m2· h C) showed a positive correlation with the cell number (x= 0.165 · 1010/m2). The average chlorophyll‐a content of 20.51 mg/m2is comparable to that of the Wadden Sea (COLIJNand DIJKEMA), Schöhsee (HO) and Lake Chilwa (Moss 1979). The average activity coefficient (P/B, mg C per mg chlorophyll‐a and hour) varied between 0.10… 1.93 and the maximum value is only 29 % of that of the phytoplankton. No significant correlation between the algal populations and the ionic concentration of the overlying water could be found because the populations are limited by lig

ISSN:0323-4320    

DOI:10.1002/aheh.19880160510

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19880160511

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY