Radiochemical determination of twelve trace elements in human blood serum

Renterghem, D. Van; Cornelis, Rita; Vanholder, Raymond

doi:10.1016/0003-2670(92)80142-t

“…Adsorption can be further reduced by adding a suitable complexing agent so long as this has no adverse affect on the subsequent analysis. For example, mercury can be stabilized as ½HgI 4 2À , and silver as ½AgðCNÞ 2 À . Containers, pipettes, and other laboratory implements contain traces of various elements both in their structure and adsorbed on the surface, and these are subject to desorption on contact with a sample, calibration solutions, or reagents, thereby contributing to a nonreproducible increase in blank results.…”

Section: Requirements With Respect To Materials and Chemicalsmentioning

confidence: 99%

“…Addition of a radioactive tracer may make it possible to monitor losses that occur during the course of an analysis [4] (! Radionuclides in Analytical Chemistry).…”

Section: Trace Losses and Contaminationmentioning

confidence: 99%

Sample Preparation for Trace Analysis

Begerow

¹

,

Dunemann

²

2006

Ullmann's Encyclopedia of Industrial Chemistry

2

0

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The article contains sections titled: 1. Introduction 1.1. A Strategy Appropriate to Trace Analysis 1.2. Avoidance of Systematic Errors 1.2.1. Trace Losses and Contamination 1.2.2. Uncertainty 2. Sample Preparation and Digestion in Inorganic Analysis 2.1. Sample Treatment after the Sampling Process 2.1.1. Stabilization, Drying, and Storage 2.1.2. Homogenization and Aliquoting 2.1.3. Requirements with Respect to Materials and Chemicals 2.2. Sample‐Preparation Techniques; General Considerations 2.2.1. Special Factors Associated with Microwave‐Assisted Digestion 2.2.2. Safety Considerations 2.3. Wet Digestion Techniques 2.3.1. Wet Digestion at Atmospheric Pressure 2.3.2. Pressure Digestion 2.3.2.1. Thermally Convective Pressure Digestion 2.3.2.2. Microwave‐Assisted Pressure Digestion 2.4. “Dry” Digestion Techniques 2.4.1. Combustion in Air 2.4.2. Combustion in Oxygen 2.4.3. Cold‐Plasma Ashing 2.4.4. Fusion 2.5. Illustrative Examples 2.5.1. Sample Preparation as a Function of Analytical Method 2.5.2. Combined Use of Multiple Decomposition Techniques 2.5.3. Comparative Merits of the Various Sample‐Preparation Techniques 2.5.4. Decomposition Procedures for Determining Nonmetals 2.6. Evaluation Criteria 2.6.1. Completeness 2.6.2. Uncertainty 2.6.3. Time Factors 2.6.4. The Final Result 2.7. Concentration and Separation of Inorganic Trace Materials 2.8. Automation and Direct Analysis 2.8.1. Automation 2.8.2. Direct Analysis 2.9. Analysis of Element Species 3. Sample Preparation in Organic Analysis 3.1. Sample Treatment after the Sampling Process 3.1.1. Stabilization, Drying, and Storage 3.1.2. Homogenization and Aliquoting 3.1.3. Requirements with Respect to Materials and Chemicals 3.2. Separation of the Analyte 3.2.1. Hydrolysis 3.2.2. Liquid ‐ Liquid Extraction 3.2.3. Soxhlet Extraction 3.2.4. Microwave‐Assisted Solvent Extraction 3.2.5. Supercritical Fluid Extraction (SFE) 3.2.6. Solid‐Phase Extraction (SPE) 3.2.7. Solid‐Phase Microextraction (SPME) 3.2.8. Stir‐Bar Adsorptive Extraction (SBSE) 3.2.9. Miscellaneous Techniques 3.3. Headspace Techniques 3.3.1. Static Headspace Technique 3.3.2. Dynamic Headspace Technique (Purge and Trap) 3.4. Determination of Trace Organic Materials in Air Samples 3.5. Analyte Concentration 3.6. Derivatization 3.7. Coupled Techniques Trace analysis is a very relevant and applications‐oriented branch of analytical chemistry. The sample preparation for trace analysis must be custom‐tailored to the problem at hand. Systematic errors can arise by contact with vessel materials, reagents, or the ambient atmosphere, as well as any change in chemical or physical state. In inorganic analysis, sample preparation has to meet the requirements for a substantially trouble‐free determination of the analyte. Digestion of the matrix (microwave digestion, wet digestion, dry digestion techniques) and subsequent careful comparison of several decomposition techniques is therefore an essentially important step. Some separation and concentration techniques of the analytes are liquid –liquid extraction, solid‐phase extraction, special precipitation reactions, and electrolytic deposition. The introduction of laboratory robots should make it possible to incorporate a significant degree of automation into the time‐consuming, labor‐intensive area of sample preparation as well, leading to more efficient, reliable, and reproducible sample work‐up. The goal of sample preparation in organic trace analysis is to isolate the analyte from the sample matrix (e.g., liquid‐liquid extraction, Soxhlet extraction, microwave‐assisted solvent extraction, steam distillation) and then concentrate it and convert it into a form suitable for analysis by the selected method. Separation and concentration of an analyte must often be followed by some type of derivatization. Various coupled sample preparation and determination processes are increasingly utilized in trace organic analysis.

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“…[1][2] The cesium level can be determined by different methods such as atomic absorption spectroscopy, 3 radioanalysis. [4][5] In this context, the use of fluorescent sensor [6][7][8][9] has several advantages in terms of sensitivity, selectivity and response time.…”

Section: Introductionmentioning

confidence: 99%

“…[6][7] Among the recognition sites, the calix [4]arene biscrown-6 ether were shown to have a good selectivity for alkali cations, especially for cesium. [10][11][12] We previously 3 reported different calix [4]arene biscrown-6 ether in which a coumarin fluorophore is introduced into both crown-ethers. [13][14] These molecules exhibit high selectivity for cesium cations with the limitation that their excitation wavelength falls in the UV region.…”

Section: Introductionmentioning

confidence: 99%

Calixarene-Based Fluorescent Sensors for Cesium Cations Containing BODIPY Fluorophore

Depauw

¹

,

Kumar

²

,

Ha‐Thi

³

et al. 2015

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New fluorescent molecular sensors based on a calix[4]arene biscrown-6 ether as coordination site and BODIPY derivative as signaling unit were synthesized, and their photophysical properties were characterized. The complexation properties of these sensors with potassium and cesium cations were investigated using both steady-state and time-resolved fluorescence methods. The studies show that the sensitivity with cations depends upon the position of substituted coordination site on the BODIPY core. The complexation with cations does not have much effect on the absorption and emission wavelength when the coordination site (calix[4]arene biscrown-6 ether) is introduced at the meso position of the BODIPY core. In contrast, the same calix[4]arene biscrown-6 ether attached via a styryl linker to the α-position of BODIPY core leads to a sensitive sensor for alkali cations thanks to the better conjugation between the coordination site and the BODIPY core. The complexation of cations induces a hypsochromic shift of the absorption and emission maximums due to the diminution of donor character of the oxygen atoms in the coordination site. The stability constants of complexes with potassium and cesium ion were measured.

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“…The decomposition process takes about 50-60 min. This system was found to give recoveries 2 95% for all elements studied in biological standard reference materials [22], human serum [23] and also in oil and fats [24]. This method suffers from the disadvantage that only one sample can be digested each time, whereas in dry ashing in oven, several samples can be processed simultaneously.…”

mentioning

confidence: 99%