Contents
XIII
18.3.2 Reversed Phase Chromatography ........................................... 343
18.3.3 Ion Chromatography .......................................................... 343
18.3.4 Ion Interaction Chromatography... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 344
18.3.5 Chelation Ion Chromatography ............................................. 346
18.3.6 Multimode and Multidimensional Liquid Chromatography ............ 347
18.3.7 Preconcentration ............................................................... 348
18.4 Analytical Applications ............................................................... 348
18.5 Detection and Hyphenated Techniques ............................................ 350
References ............................................................................... 353
19 PIXE Analysis for Trace Elements in Marine Environments ................. 357
19.1 Introduction ............................................................................ 357
19.2 The PIXE Technique and the Experimental Set-up ............................... 358
19.3 Sensitivity and Detection Limits of the Technique ............................... 360
19.4 The PIXE Targets from Environmental Samples .................................. 361
19.5 The Proton Microbeam and its Applications .................................... 364
19.6 PIXE Application in the Study of Pollutant Enrichment in
Marine Aerosols ..................................................................... .. 365
19.7 The Study of the Venice Lagoon Ecosystem by Means of the
PIXE Technique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 366
19.7.1 The Fate of Pollutants Discharged into the Lagoon ...................... 366
19.7.2 Trace Element Distribution in Surface Bottom Sediment ............... 367
19.7.3 The Vertical Profile of Trace Elements in Pore Water. .
. ........ 367
19.7.4 Trace Elements in Surface Water and the Effect of
Fresh and Salt Water Mixing ........ .............. ............... ......... 368
References .................................................. ............................ 369
20 Potentiometry for the Study of Acid-Base Properties of Sediments ..... 371
20.1 Introduction ........................................................................... 371
20.2 Sediment: What is it? ................................................................. 372
20.3 The Solid-Water Interface .......................................................... 373
20.4 Titration Procedure .................................................................... 376
20.5 Elaboration of the Potentiometric Data ..........
. ....................... 379
20.6 Results of the Potentiometric Approach..........
. ..................... 381
References ............................................................................... 384
21 (hemometries for Sampling and Analysis:
Theory and Environmental Applications ....................................... 387
21.1 Introduction ............................................................................ 387
21.2 The Fundamental Tools of Chemometrics .............................
. . . . .. 388
21.2.1 Data Pretreatments
(The Importance of Data Knowledge and of Problem) .....
. .... 388
21.2.2 Similarity and Clustering ..................................................... 389
21.2.3 Principal Components ........................................................ 390
21.2.4 Class-Modelling Techniques ................................................. 394
21.2.5 Regression Techniques, Responses and Predictors ....................... 394
21.2.6 Regression Techniques, Biased and Unbiased Techniques............... 396
XIII
18.3.2 Reversed Phase Chromatography ........................................... 343
18.3.3 Ion Chromatography .......................................................... 343
18.3.4 Ion Interaction Chromatography... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 344
18.3.5 Chelation Ion Chromatography ............................................. 346
18.3.6 Multimode and Multidimensional Liquid Chromatography ............ 347
18.3.7 Preconcentration ............................................................... 348
18.4 Analytical Applications ............................................................... 348
18.5 Detection and Hyphenated Techniques ............................................ 350
References ............................................................................... 353
19 PIXE Analysis for Trace Elements in Marine Environments ................. 357
19.1 Introduction ............................................................................ 357
19.2 The PIXE Technique and the Experimental Set-up ............................... 358
19.3 Sensitivity and Detection Limits of the Technique ............................... 360
19.4 The PIXE Targets from Environmental Samples .................................. 361
19.5 The Proton Microbeam and its Applications .................................... 364
19.6 PIXE Application in the Study of Pollutant Enrichment in
Marine Aerosols ..................................................................... .. 365
19.7 The Study of the Venice Lagoon Ecosystem by Means of the
PIXE Technique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 366
19.7.1 The Fate of Pollutants Discharged into the Lagoon ...................... 366
19.7.2 Trace Element Distribution in Surface Bottom Sediment ............... 367
19.7.3 The Vertical Profile of Trace Elements in Pore Water. .
. ........ 367
19.7.4 Trace Elements in Surface Water and the Effect of
Fresh and Salt Water Mixing ........ .............. ............... ......... 368
References .................................................. ............................ 369
20 Potentiometry for the Study of Acid-Base Properties of Sediments ..... 371
20.1 Introduction ........................................................................... 371
20.2 Sediment: What is it? ................................................................. 372
20.3 The Solid-Water Interface .......................................................... 373
20.4 Titration Procedure .................................................................... 376
20.5 Elaboration of the Potentiometric Data ..........
. ....................... 379
20.6 Results of the Potentiometric Approach..........
. ..................... 381
References ............................................................................... 384
21 (hemometries for Sampling and Analysis:
Theory and Environmental Applications ....................................... 387
21.1 Introduction ............................................................................ 387
21.2 The Fundamental Tools of Chemometrics .............................
. . . . .. 388
21.2.1 Data Pretreatments
(The Importance of Data Knowledge and of Problem) .....
. .... 388
21.2.2 Similarity and Clustering ..................................................... 389
21.2.3 Principal Components ........................................................ 390
21.2.4 Class-Modelling Techniques ................................................. 394
21.2.5 Regression Techniques, Responses and Predictors ....................... 394
21.2.6 Regression Techniques, Biased and Unbiased Techniques............... 396