PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Graphite”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources
PubMed1981

Lead in bone. I. Direct analysis for lead in milligram quantities of bone ash by graphite furnace atomic absorption spectroscopy.

A method for direct lead content analysis of milligram quantities of bone ash by flameless atomic absorption spectroscopy is described. Bone ash (25 mg) is dissolved with HNO3 and diluted with H2O and La2O3 (1,000 micrograms/ml) solution. Lanthanum ion is used to suppress matrix interferences possibly arising in part from sulfate components of the bone ash. Two bulk bone samples (about 14 and 60 micrograms Pb/g ash, respectively) were used to determine daily, within-day, and overall variability of the method. Values for "low lead" bone samples were 14.08 +/- 1.74 (SD) microgram Pb/g ash and for "high lead" bone samples were 60.85 +/- 5.24 (SD) microgram Pb/b ash. The overall value of 58 lead recovery determinations from bone ash analysis was 103.5% (+/- 12.9% SD). These values compare favorably with results previously reported using gram amounts of sample.

Bone and Bones↗
PubMedDate not supplied

Analysis of submicrogramme levels of cadmium in whole blood, urine and hair by graphite furnace atomic absorption spectroscopy.

Toxicological studies require the analysis of heavy metals in many widely differing samples. In this paper, a simple and accurate method is described for the determination of cadmium in whole blood, urine, and hair. The blood and urine samples were digested in nitric acid at 70 degrees C, and the hair was digested in a 1:1 mixture of nitric and sulphuric acid. Although a low temperature necessitated longer digestion, the operation was conveniently carried out overnight. The digestion and any subsequent extraction or dilution was carried out in the same tube. The methods used optimised digestion efficiency and minimised sample contamination. The method was also found to be precise and highly reproducible with relative standard deviation (RSD) values within 5%.

Cadmium↗
PubMed2004

Low-frequency Raman and Brillouin spectroscopy from graphite, diamond and diamond-like carbons, fullerenes and nanotubes.

Inelastic light scattering by acoustic phonons (Brillouin scattering) is a useful tool for probing material properties at the submicrometre scale. In media which are statistically homogeneous at this scale, it gives access to the acoustic properties and the elastic moduli. In nanostructures it probes the vibrational properties at the mesoscopic scale. Applications to carbonaceous materials are reviewed.

Acoustics↗
PubMed2002

Bimetallic catalyst for synthesizing quasi-aligned, well-graphitized multiwalled carbon nanotube bundles on a large scale by the catalytic chemical vapor deposition method.

An effective method of growth by catalytic chemical vapor deposition (CCVD) to get a large-scale yield of carbon nanotubes is reported. In this method, acetylene is decomposed catalytically over well-dispersed metal particles (Co-Fe and Co-Ni) embedded in commercially available zeolite at a lower temperature (600-700 degrees C). The two binary-metal catalysts (Co-Fe and Co-Ni) used are compared by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Crucial reaction parameters, such as reaction time, temperature, and the effect of purity of gas to obtain optimum production of the nanotubes, both qualitatively and quantitatively, are also reported.

Catalysis↗