Calibration curve

About: Calibration curve is a research topic. Over the lifetime, 6552 publications have been published within this topic receiving 95128 citations.

Magnetic nanoparticle temperature estimation

Abstract: The authors present a method of measuring the temperature of magnetic nanoparticles that can be adapted to provide in vivo temperature maps. Many of the minimally invasive therapies that promise to reduce health care costs and improve patient outcomes heat tissue to very specific temperatures to be effective. Measurements are required because physiological cooling, primarily blood flow, makes the temperature difficult to predict a priori. The ratio of the fifth and third harmonics of the magnetization generated by magnetic nanoparticles in a sinusoidal field is used to generate a calibration curve and to subsequently estimate the temperature. The calibration curve is obtained by varying the amplitude of the sinusoidal field. The temperature can then be estimated from any subsequent measurement of the ratio. The accuracy was 0.3 degree K between 20 and 50 degrees C using the current apparatus and half-second measurements. The method is independent of nanoparticle concentration and nanoparticle size distribution.

Laser-induced breakdown spectroscopy of composite samples: comparison of advanced chemometrics methods.

Abstract: Laser-induced breakdown spectroscopy is used to measure chromium concentration in soil samples. A comparison is carried out between the calibration curve method and two chemometrics techniques: partial least-squares regression and neural networks. The three quantitative techniques are evaluated in terms of prediction accuracy, prediction precision, and limit of detection. The influence of several parameters specific to each method is studied in detail, as well as the effect of different pretreatments of the spectra. Neural networks are shown to correctly model nonlinear effects due to self-absorption in the plasma and to provide the best results. Subsequently, principal components analysis is used for classifying spectra from two different soils. Then simultaneous prediction of chromium concentration in the two matrixes is successfully performed through partial least-squares regression and neural networks.

Working with ion-selective electrodes

Abstract: 1 Fundamentals of Potentiometry.- 1.1 Electrode Processes.- 1.2 The Nernst Equation.- 1.3 Potential-Determining Ions.- 1.4 Ion-Selective Electrode Materials.- 1.5 The Potentiometric Selectivity Coefficient as a Quantitative Indication of the Electrode Selectivity.- 2 Electrode Potential Measurements.- 2.1 Reference Electrodes.- 2.2 The Standard Hydrogen Electrode as a Primary Reference Electrode.- 2.2.1 Preparation.- 2.2.2 Characteristics.- 2.3 The Liquid Junction Potential.- 2.3.1 Origin.- 2.3.2 Calculation.- 2.3.3 Salt Bridge Electrolytes.- 2.3.4 Construction of the Salt Bridge Electrolyte/Sample Solution Contact Zone.- 2.3.5 Cells Without Liquid Junction.- 2.4 Secondary Reference Electrodes.- 2.4.1 Silver/Silver Chloride.- 2.4.1.1 Preparation.- 2.4.1.2 Characteristics.- 2.4.2 Thallium Amalgam/Thallium (I) Chloride (Thalamid(R)).- 2.4.2.1 Characteristics.- 2.4.3 Mercury/Mercury (I) Chloride (Calomel).- 3 Ion-Selective Electrodes.- 3.1 General Construction Principles.- 3.2 Solid-State Membrane Electrodes.- 3.2.1 Glass Membrane Electrodes For Li+, Na+, K+, Rb+, Cs+, NH4+, NR4+, Ag+, Tl+ Ions.- 3.2.1.1 Construction.- 3.2.1.2 Characteristics.- 3.2.1.3 Handling.- 3.2.1.4 Sample Preparation.- 3.2.2 Homogeneous Solid-State Membrane Electrodes For Ag+, Cd2+, Cu2+, Pb2+, S2-, F-, Cl-, Br-, I-, SCN-, CN- Ions.- 3.2.2.1 Principles.- 3.2.2.2 Construction.- 3.2.2.3 Preparation of Solid-State Membrane Electrodes Based on Ag2S.- 3.2.2.4 Characteristics.- 3.2.2.5 Handling.- 3.2.2.6 Sample Preparation.- 3.2.3 Heterogeneous Solid-State Membrane Electrodes For Ag+, Cl-, Br-, I-,CN-, SCN-, S2- Ions.- 3.2.3.1 Construction.- 3.2.3.2 Preparation.- 3.2.3.3 Characteristics.- 3.2.3.4 Handling.- 3.3 Porous and Nonporous Supported Ion Exchanger and Neutral Carrier Membrane Electrodes.- 3.3.1 Ion-Exchangers For Ca2+, Me2+ Cations and Cl-, ClO4-, NO3-, BF4- Anions.- 3.3.2 Neutral Carrier Compounds For Li+, Na+, K+, Rb+, Cs+, NH4+, NR4+, Ca2+ and Ba2+ Cations.- 3.3.3 Construction.- 3.3.4 Preparation of PVC Membrane Electrodes.- 3.3.5 Characteristics.- 3.3.6 Handling.- 3.3.7 Further Electro-Active Phases.- 3.4 Solid State Electrodes with Electroactive Coatings.- 3.5 Gas Sensors For CO2, NH3, SO2, NO2, HF, H2S, HCN, etc..- 3.5.1 Principles.- 3.5.2 Construction.- 3.5.3 Characteristics of Gas-Sensitive Electrodes.- 3.5.4 Handling.- 3.5.5 Sample Preparation.- 3.6 Bio-Sensors.- 3.6.1 Principles.- 3.6.2 Construction.- 3.6.3 Preparation of Enzyme Electrodes.- 3.6.4 Characteristics of Bio-Sensors.- 3.6.5 Sample Preparation with Bio-Sensors.- 4 Measuring Techniques with Ion-Selective Electrodes.- 4.1 Equivalent Circuit for a Cell with Liquid Junction.- 4.2 Measuring the EMF of an Electrochemical Cell.- 4.3 Choosing an EMF Measuring Device.- 4.4 Characteristics of Electrometer Amplifiers.- 4.4.1 Resolving Power.- 4.4.2 Insulation Problems.- 4.4.3 Charging Phenomena.- 4.4.4 Ground Loops.- 5 Analysis Techniques Using Ion-Selective Electrodes.- 5.1 Calibration Curves.- 5.1.1 Determination of Activity Using an Activity Calibration Curve.- 5.1.2 Determination of Concentration Using a Concentration Calibration Curve.- 5.2 Direct Indication on the pH or plon Scale of an Instrument.- 5.3 Titration Procedures for Determining Concentrations.- 5.3.1 Prerequisites.- 5.3.2 Titration Errors.- 5.3.3 Sample Preparation for Titrations.- 5.3.4 Titration to a Pre-determined EMF Value.- 5.3.4.1 On the Basis of a Titration Curve.- 5.3.4.2 On the Basis of a Concentration Cell Set-Up.- 5.3.5 "Chemically Linearized" Titration Curves (One Point Titration).- 5.4 Concentration Determinations with the Help of a Standard Addition with a Known Electrode Slope S.- 5.4.1 Measuring the Change in EMF upon Addition of a Standard Solution to the Sample Solution.- 5.4.2 Measuring the Change in EMF upon Addition of the Sample Solution to a Standard Solution.- 5.5 Concentration Determinations with the Help of a Standard Addition with an Unknown Electrode Slope S.- 5.5.1 Method of Double Standard Addition.- 5.5.2 Method of Standard Addition with Subsequent Dilution.- 5.6 Practical Example of the Addition Method: Sodium and Potassium Determination in Blood Serum.- 5.7 Concentration Determinations with the Help of a "Mathematically Linearized" Titration Curve.- 5.8 Practical Example of the Gran Extrapolation Method: Determination of Chloride in the ppm Range.- 5.8.1 Principles.- 5.8.2 Preparatory Work.- 5.8.3 Blank Determination.- 5.8.4 Chloride Content Determination of the Sample Solution.- 5.9. Determination of Some Characteristic Electrode Parameters.- 5.9.1 Determination of the Detection Limit.- 5.9.2 Determination of the Selectivity Coefficient.- 6 Applications of Ion-Selective Electrodes.- 6.1 Physiology, Biology, Medicine.- 6.1.1 Measurements in Extracellular Fluids.- 6.1.1.1 In-vitro Measurements.- 6.1.1.1.1 Sample Preparation.- 6.1.1.1.2 The Indicating Electrode.- 6.1.1.1.3 The Reference Electrode.- 6.1.1.2 In-vivo Measurements.- 6.1.2 Measurements of Intracellular Ion Activities.- 6.1.2.1 Preparation of Ion-Selective Microelectrodes.- 6.1.2.2 Guarded Signal Wires for Extremely High Ohmic Electrodes.- 6.1.2.3 Reference Microelectrodes.- 6.1.2.4 Special Amplifiers for Microelectrode Applications.- 6.2 Continuous Measurements in Industry and Environmental Research.- 6.2.1 Flow-thru Cells.- 6.2.1.1 Influence of Grounding.- 6.2.1.2 Influence of Temperature.- 6.2.1.3 Analysis Techniques with Flow-thru Measurements.- 6.2.1.4 Flow-thru Measurements without Reference Electrodes.- 6.2.1.4.1 Direct Potentiometry.- 6.2.1.4.2 Concentration Determination through Standard Solution Addition.- 6.2.1.4.3 Indirect Concentration Determination.- 6.2.1.4.4 The Cyanide Monitor as an Example of Industrial On-Line Measurements.- 6.2.2 Concentration Determination Via a Continuous Titration.- Outlook.- A.1 Concentration, Activity and Activity Coefficient.- A.1.1 Preparing Accurate Activity Calibration Solutions.- A.2 Survey of the Temperature Dependence of Commonly Used Reference Electrodes.- A.3 Table for Evaluation Using Analysis Technique 5.4.1.- A.4 Table for Evaluation Using Analysis Technique 5.4.2.- A.5 Table for Evaluation Using Analysis Technique 5.5.1.- A.6 Table for Evaluation Using Analysis Technique 5.5.2.- A.7 Evaluation Table for Standard Addition + 1:1 Dilution.- A.8 Ion-Selective Electrode Manufacturers and/or Dealers.- Literature.- Index of Symbols Used.