Cobalt gravimetric analysis

Recently, two pyrazine (pz)-linked hetero-triads of cobalt phthalocyanine (CoPc) and ZnTPP, namely (CoPc)-pz-(ZnTPP)-pz-(CoPc) (15) and (ZnTPP)-pz-(CoPc)-pz-(ZnTPP) (16), have been prepared [30], The thermal properties of these triads and related macrocyclic components have been studied by thermal gravimetric analysis and differential scanning calorimetry. It has been found that the thermal stability of axial coordination increases in the order ZnPc(pz)2 < ZnTPP(pz)2 sa CoPc(pz)2, and the thermal decomposition of the triads 15 and 16 proceeds firstly via the degradation of the spacer ligand. 

Gravimetric Analysis of Cobalt as CoSOt. Approximately 200 mg. of the sample is decomposed in a crucible with concentrated sulfuric acid in slight excess. The crucible is... 

For colorimetric or gravimetric determination l-nitroso-2-naphthol can be used. For chromatographic ion exchange (qv), cobalt is isolated as the nitroso-(R)-salt complex. The cyanate complex is used for photometric determination and the thiocyanate for colorimetry. A rapid chemical analysis of... 

Bromo-2-pyridyla2o)-5-diethylamiQophenol (5-Br-PADAP) is a very sensitive reagent for certain metals and methods for cobalt have been developed (23). Nitroso-naphthol is an effective precipitant for cobalt(III) and is used in its gravimetric determination (24,25). Atomic absorption spectroscopy (26,27), x-ray fluorescence, polarography, and atomic emission spectroscopy are specific and sensitive methods for trace level cobalt analysis (see... 

Hydrazine sulfate is used as a reducing agent in analytical chemistry for gravimetric measurement of nickel, cobalt, and other metals, and in peptide analysis in the separation of polonium from tellurium as an antioxidant in... 

Method 1. Polymerization of Bis(thiooxamides) with Metal Salts Dithiooxamide, or rubeanic acid as it is commonly referred to in the literature, has been widely used for the quantitative analysis of metals. In particular, copper, nickel, and cobalt form complexes that can be analyzed gravimetrically... 

The cobalt content was determined by atomic absorption at the service central d analyse du CNRS (Vemaison, France). Differential thermal and thermo gravimetric analyses (DTA/TG) were conducted in flowing air (75 mL min ) at a heating rate of 5°C min . Surface area analysis was performed using the BET method. N2 was selected as the adsorbent, and analysis was performed at liquid nitrogen temperature (-196 C). X-ray diffraction (XRD) measurements were made at room temperature (X =1.5418 A). The diffraction patterns have been indexed by comparison with the Joint Committee on Powder Diffraction Standards (JCPDS) files. Temperature Programmed Reduction (TPR) was performed using a 5% H2/Ar mixture (30 inL min - 5°C min ). 

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