Analysis, metals

In similar circumstances, silver salts leave a residue of metallic silver lead and copper salts usually leave a residue of the corresponding oxide calcium and barium salts leave a resirlne of the carbonate or oxide. Identify the metal in all such cases by the usual tests of qualitative inorganic analysis. Metals other than the above are seldom encountered in elementan qualitative analysis. 

Kinetic analysis (metal ion acts as catalyst) Sensitive, highly selective, only needs small samples 1 Q- to 10- M... 

Figure 15-12 is a schematic illustration of a technique known as acid volatile sulfides/ simultaneously extracted metals analysis (AVS/SEM). Briefly, a strong acid is added to a sediment sample to release the sediment-associated sulfides, acid volatile sulfides, which are analyzed by a cold-acid purge-and-trap technique (e.g., Allen et ai, 1993). The assumption shown in Fig. 15-12 is that the sulfides are present in the sediments in the form of either FeS or MeS (a metal sulfide). In a parallel analysis, metals simultaneously released with the sulfides (the simultaneously extracted metals) are also quantified, for example, by graphite furnace atomic absorption spectrometry. Metals released during the acid attack are considered to be associated with the phases operationally defined as "exchangeable," "carbonate," "Fe and Mn oxides," "FeS," and "MeS."... 

Fairman B, Hinds MW, Nelms SM, Penny DM, Goodall P (1999) Atomic Spectrometry Update Industrial analysis metals, chemicals and advanced materials. J Anal Atom Spectrom 14 2001-2030. 

Dry-ashing Ignition of organic matter in a furnace. Resulting ash dissolved in acid for further analysis Metals in organic solid samples (e.g. metals in foodstuffs)... 

LASER-FLASH KINETIC ANALYSIS METAL ION CATALYSIS METALLOTHIONEINS Metal-nucleotide complex,... 

P.D. Snell (Ed.), Potentiometric and Fluorometric Methods of Analysis. Metals. Parts 1 2, Wiley, New York, 1978. 

Radiography - [NONDESTRUCTIVEEVALUATION] (Voll7) - [RADIOACTIVETRACERS] (Vol20) -for explosively clad metal analysis [METALLIC COATINGS - EXPLOSIVELY CLAD METALS] (Vol 16)... 

Qualitative chemistry is an area of chemistry concerned with identifying substances. In Activity 9.1 you will perform a qualitative analysis to detect the presence of certain ions that, in turn, may reveal an art forgery. The ions could come from paints that were not available at the time of the artwork. In this qualitative analysis, metal ions (cations) and nonmetal ions (anions) are reacted with solvents and with each other. Then the cations and anions present are identified by the products produced. In addition, flame tests and pH determinations are used to identify ions. Qualitative analysis is an engaging opportunity for you to develop experience with chemical change and review solubility principles. Nowadays, however, most of the time a chemist analyzes a substance to detect ion content using quantitative analytical computerized instruments. 

Redox titrations are often performed for metal analysis. Metals in their lower oxidation states are common reducing agents. This includes Fe2+, Sn2+, Mo3+, W3+, Ti3+, Co2+, U4+, and V02+. Sodium thiosulfate, (Na2S203) is one of the most widely used reductants in iodometric titrations. Other reducing agents include sodium arsenite and phenylarsine oxide. Iodometric titration is discussed separately in the next section. 

After completing the necessary preparation procedures, the Sample Preparation Section personnel place extracts in sealed, labelled vials and store them in specially designated refrigerators at 2-6°C. Organic extracts will stay refrigerated until the time of analysis. Metal digestates are stored at room temperature. Completed preparation bench sheets and other support documentation become part of the permanent sample record. When we request that samples be composited at the laboratory, for most types of analysis the compositing will be typically done at the Sample Preparation Section. 

Friel J, et al. 2000. Practical guide to image analysis. Metals Park ASM International 290. 

Electrochemical biosensing of DNA sequences using direct electrochemical detection of DNA hybridization, adsorptive striping analysis, metal complex hybridization indicators, organic compound electroactive hybridization indicators and renewable DNA probes have been considered [65,67,72,73]. With metal complexes and organic compound electroactive hybridization indicators, non-specific adsorption can influence the results [68,94]. Chrono-potentiometric detection was used to monitor the hybridization onto screen-printed carbon electrodes by following the oxidation of the guanine peak, which decreases in the presence of the complementary strand [64,68,73]. 

In order to show the effect of total salt quantity in the atomizer, a series of injections were made for cadmium and manganese analysis with different volumes of solution but with the same total quantity of the analysis metal present per injection. Three series of injections were made—in distilled water, in seawater, and in seawater diluted to maintain the total salt quantity per injection constant. The results are shown in Figures 15 and 16 for manganese and cadmium, respectively. It is... 

Stefanescu, D.M. Juretzko, F.R. Dhindaw, B.K. Catalina, A. Sen, S. Curreri, P.A. Particle engulf-ment and pushing by solidifying interfaces Part II. Microgravity experiments and theoretical analysis. Metall. Mater. Trans. A. 1998, 29A, 1697-1706. 

With Pd- or Pt-containing catalysts the problem arises how to discriminate between reduced Ni and the reduced metal. Temperature-programmed reduction experiments ( 5) have shown that Pd is reduced arond 80 C. Reduction of Ni starts at 200 to 300 C. Reoxidation and rereduction point to a possible Pd-Ni alloy formation. We have studied Pd-NiSMM and Pt-NiSMM samples after reduction at 350 and 450 C by TEM combined with electron microprobe analysis. Metal crystallites with a maximum diameter of 20 nm are formed. Part of them contain Pd and Pt, respectively. Because of the background of lattice Ni2+, reduced Ni is difficult to distinguish by this technique. Since, moreover, large metal crystallites are observed from which no Pd or Pt signal is obtained at all, it seems reasonable to assume that these crystallites are reduced Ni. The presence of alloys cannot be ruled out. 

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