Studies on complexation and solvent extraction of lanthanides in the presence of diaza-18-crown-6-di-isopropionic acid.
Stability constants of some lanthanides with K22DAP (diaza-18-crown-6-diisopropionic acid) were determined by potentiometric titration method. The logarithmic values of these constants for La(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III), Er(III), and Lu(III) are 11.14, 11.43, 11.78, 11.74, 11.95, 12.09, 11.49, and 10.88, respectively. Solvent extraction studies were carried out on the K22DAP complexes of La(III), Nd(III) and Lu(III) using TTA (thenoyltrifluoroacetone) as an extractant in different diluents. It appears that nitrobenzene, a diluent with high dielectric constant, favors the extraction of the complexes. Extraction rates of the K22DAP complexes of lanthanides were investigated at pH 5.5 and 8.0 with TTA in chloroform. The rates of extraction are found to be dependent upon the nature of the extracted species. Competitive extractions were carried out to see if selective extractions could be achieved.
Computational methods for the determination of formation constants
1 The Determination of Formation Constants: An Overview of Computational Methods for Data Processing.- 1. Introduction.- 2. Direct Search and Univariate Methods.- 2.1. Grid, Star, and Composite Designs.- 2.2. Fibonacci and Golden Section.- 2.3. Hooke and Jeeves, Simplex.- 2.4. Quadratic and Cubic Interpolation Methods.- 2.5. Summary.- 3. Least-Squares Methods.- 3.1. Newton-Raphson.- 3.2. Gauss-Newton.- 3.3. Levenberg and Marquardt.- 3.4. Objective Function Differentiation.- 4. Other Methods.- 4.1. Curve Fitting.- 4.2. HOSK Method.- 5. Summary.- 6. References.- 2 Strategies for Solution Equilibria Studies with Specific Reference to Spectrophotometry.- 1. Elucidation of the Equilibrium Model.- 1.1. Introduction.- 1.2. Experimental Techniques.- 1.3. Data Analysis.- 1.4. Adequacy of the Selected Model.- 2. Determination of pKa's from Absorbance pH Studies.- 2.1. Introduction.- 2.2. Measurement of Absorbance vs. pH Data.- 2.3. Preliminary Data Handling.- 2.4. Curve-Fitting Analysis of the Absorbance vs. pH Curve.- 2.5. Matrix Regression Analysis.- 2.6. Thermodynamic Dissociation Constants.- 3. Initial Methods for Investigating Complex Equlibria.- 3.1. Introduction.- 3.2. Graphical Analysis of Absorbance vs. pH Curves.- 3.3 Analysis of Absorbance vs. pH Curves Using PRCEK.- 3.4. Continuous Variation Techniques.- 3.5. Mole Ratio Techniques.- 3.6. Method of Corresponding Solutions.- 4. Conclusions.- 5. References.- 3 MAGEC: A Program for the Definite Calibration of the Glass Electrode.- 1. Introduction.- 2. Descrition of the Program MAGEC.- 2.1. Theory.- 2.2. Use of MAGEC for Electrode Calibration.- 2.3. Conclusions.- 3. References.- 4. Instructions for the Use of MAGEC.- 4.1. Basic Principles.- 4.2. Data Input Requirements.- 5. Presentation of the Program.- 5.1. Listing of MAGEC.- 5.2. Input Data.- 4 SCOGS2: A Nonlinear Least-Squares Program for the Evaluation of Formation Constants of Metal Complexes.- 1. Introduction.- 2. Description of the Program SCOGS2.- 2.1. General.- 2.2. MAIN Program of SCOGS2-SCOGSH Option.- 2.3. SCOGSM Option.- 2.4. Subroutine COGSNR.- 2.5. Limits of SCOGS2.- 2.6. Some Examples of the Use of SCOGS.- 2.7. Using SCOGS2 to Build an Equilibrium-Model.- 3. References.- 4. Instructions for SCOGS2.- 5. Presentation of the Program.- 5.1. Listing of SCOGS2.- 5.2. Input Data.- 5.2.1. Data for the System Copper(II)-Phosphonoacetate.- 5.2.2. Data for the System Copper(II)-Histidine (3-hydroxo-1-methylpyridin-4-(1H)-one).- 5.2.3. Data for the System Copper-p-Sulfonatobenzaldehyde thiosemicarbazone.- 5 MINIQUAD and MIQUV: Two Approaches for the Computation of Formation Constants from Potentiometric Data.- 1. Introduction.- 2. Description of the Programs.- 2.1. Program MINIQUAD.- 2.2. Program MIQUV.- 2.3. Comments.- 3. References.- 4. Instructions for the Programs.- 4.1. Details of the Input File.- 4.2. Description of the Output.- 5. Presentation of the Programs.- 5.1. Listing of the MINIQUAD.- 5.1.1. Input Data.- 5.2. Listing of MIQUV.- 5.2.1. Input Data.- 6 SQUAD: Stability Quotients from Absorbance Data.- 1. Introduction.- 2. Description of the Program SQUAD.- 2.1. Mathematical Algorithms.- 2.2. Principles of Data Input.- 2.3. Suggestions for the Use of SQUAD.- 2.4. Modifications to SQUAD.- 3. References.- 4. Instructions for SQUAD.- 4.1. Introduction.- 4.2. Details of the Data Input.- 5. Presentation of the Program.- 5.1. Listing of SQUAD.- 5.2. Input Data.- 7 General Computer Programs for the Determination of Formation Constants from Various Types of Data.- 1. Multiparametric Curve Fitting Using ABLET.- 1.1. Introduction.- 1.2. The "Pit-Mapping" Technique.- 1.3. Description of the Program ABLET.- 1.3.1. Routines Specific to the Model.- 1.3.2. Basic Routines of the ABLET Family.- 1.4. Data Input Instructions.- 1.4.1. Introduction.- 1.4.2. Data Input Requirements.- 1.4.3. Algorithmic and Heuristic Strategies.- 1.5. Listing of ABLET.- 2. MRLET: Formation Constants of MmLn from Mole Ratio Data.- 2.1. Model Formulation.- 2.2. Description of MRLET.- 2.3. Data Input Requirements.- 2.4. Presentation of MRLET.- 2.4.1. Listing of MRLET.- 2.4.2. InputData.- 3. POLET: Formation Constants from Potentiometric Data.- 3.1. Model Formulation.- 3.2. Description of POLET.- 3.3. Data Input Requirements.- 3.4. Presentation of POLET.- 3.4.1. Listing of POLET.- 3.4.2. Input Data.- 4. EXLET: Formation Constants and Related Parameters from Spectrophotometric Extraction Data.- 4.1. Model Formulation.- 4.2. Description of EXLET.- 4.3. Data Input Requirements.- 4.4. Presentation of EXLET.- 4.4.1. Listing of EXLET.- 4.4.2. InputData.- 5. Other Programs of the ABLET Family.- 5.1. DHLET: Estimation of Thermodynamic Dissociation Constants and Extended Debye-Huckel Parameters.- 5.2. DCLET: Estimation of Successive Dissociation Constants from pH-Absorbance Data.- 5.3. NCLET: Evaluation of Competitive Equilibria in a Chelatometric Titration.- 5.3.1. Listing of MAIN, DATA, VBBE, and SKRIK for NCLET.- 6. References.- 8 PSEQUAD: A Comprehensive Program for the Evaluation of Potentiometric and/or Spectrophotometric Equilibrium Data Using Analytical Derivatives.- 1. Introduction.- 2. Description of the Program PSEQUAD.- 2.1. Calculation of the Free Concentrations.- 2.2. Refinement of the Formation Constants and/or the Molar Absorptivities.- 2.3. Model Selection by PSEQUAD.- 2.4. Estimation of Parameter Correlation.- 2.5. Program Limits.- 3. References.- 4. Program Instructions.- 4.1. Introduction.- 4.2. Input of Potentiometric and/or Photometric Data.- 4.3. Data Processing Options and Instructions.- 5. Presentation of the Program.- 5.1. Listing of PSEQUAD.- 5.2. Input Data.- 5.2.1. Experimental Details.- 5.2.2. Data for the System Copper(II)-Nitriloacetic Acid.- 5.3. Output from PSEQUAD.- 9 STBLTY: Methods for Construction and Refinement of Equilibrium Models.- 1. Introduction.- 2. Program Description.- 2.1. Computer Generation of Potentiometric Data and Distribution of Species.- 2.2. Data Reduction and Bjerrum Analysis.- 2.3. Free-Ion Concentration in Solution (FICS) Methodology.- 2.4. Average Composition of Species in Solution (ACSS) Methodology.- 2.5. Linear Least-Squares Refinement of Constants.- 2.6. Nonlinear Least-Squares Refinement of Constants: pH Data.- 2.7. Nonlinear Least-Squares of Constants: pM, pL, and pH Data.- 2.8. Nonlinear Least-Squares Refinement of the Total Concentrations.- 2.9. Analysis of Variance.- 2.10. Acknowledgments.- 3. References.- 4. Description of Batch Input Protocol.- 4.1. Fantasy Calculation.- 4.1.1. Instructions for Data Input.- 4.1.2. Input Data for Fantasy Calculation.- 4.2. Data Reduction.- 4.2.1. Instructions for Data Input.- 4.2.2. Input Data for Data Reduction.- 4.3. Variation.- 4.4 PX From Variation.- 4.5 Stoichiometric Coefs.- 4.5.1. Instructions for Data Input.- 4.5.2. Input Data for Variation, PX From Variation, and Stoichiometric COEFS.- 4.6. Linear LS Refine.- 4.7. Nonlinear LS Refine.- 4.7.1. Instructions for Data Input.- 4.7.2. Input Data for Nonlinear LS Refine.- 4.8. Analysis of Variance.- 4.8.1. Instructions for Data Input.- 4.8.2. Input Data for Analysis Variance.- 5. Source Listing of Stblty.
Dating of Historical Manuscripts Using Spectrometric Methods: A Mini-Review
An overview is provided of spectrometric methods useful for age estimation of historical manuscripts (medieval ones in particular), in order to confirm their authenticity. Individual methods (infrared and Raman spectroscopy, mass spectrometry, atomic emission spectroscopy, X-ray spectroscopy, and electron scanning microscopy) are discussed and examples of their application described. The following general strategy can be recommended for dating and/or authenticating of historical manuscripts. First of all, the pigment analysis should be carried out using Raman spectroscopy (distinguishing the period and modern pigments), followed by PIXE ink analysis (solving the question of ink homogeneity). Finally, the radiocarbon dating of the writing support, potentially supplemented by the ink dating using scanning Auger microscopy should be performed.