Objective: To establish a inductively coupled plasma mass spectrometry method for the determination of trace cobalt and tungsten in human urine. Methods: The authors used 1% nitric acid solution as diluent in October-December 2021, the sample dilution factor and internal standard element were optimized by single factor rotation experiment, and the difference between the working curve and the standard curve was compared. Results: The method uses working curve to determine cobalt and tungsten in urine, the linear range of this method was 0.0~10.0 μg/L, the correlation coefficient was 0.999 9, the detection limits respectively were 0.005 μg/L (cobalt) and 0.09 μg/L (tungsten), the recoveries of samples respectively were 87.0%~100.2% (cobalt) and 89.4%~104.8% (tungsten), the relative standard deviations respectively were 0.4%~4.4% (cobalt) and 0.6%~3.8% (tungsten) . Conclusion: A simple and rapid method for determination of cobalt and tungsten in urine has been established. This method has the advantages of simple operation, high sensitivity, low detection limit and good stability. It is suitable for determination of cobalt and tungsten in urine of all kinds of people.
Humans ; Cobalt/analysis* ; Tungsten/analysis* ; Spectrum Analysis ; Nitric Acid ; Mass Spectrometry

AIMTo study the electrochemical behavior of daunorubicin at Co/GC ion implantation modified electrode.

METHODSWith Co/GC ion implantation modified electrode as working electrode, daunorubicin was determined by voltammetry in 0.05 mol x L(-1) Na2HPO4-KH2PO4 (pH 6.82) solution.

RESULTSA sensitive reductive peak of daunorubicin was obtained by linear sweep voltammetry. The peak potential was -0.60 V (vs SCE). The peak current was proportional to the concentration of daunorubicin over the range of 2.84 x 10(-8) - 1.42 x 10(-6) mol x L(-1) and 1.42 x 10(-6) - 1.28 x 10(-5) mol x L(-1) with the detection limit of 1.42 x 10(-8) mol x L(-1). The reduction wave was applied to the determination of daunorubicin. The electrochemical behavior and reaction mechanism were studied by linear sweep and cyclic voltammetry.

CONCLUSIONThe reduction process was quasi-reversible with adsorption characteristics.

Antibiotics, Antineoplastic ; analysis ; chemistry ; Carbon ; Cobalt ; Daunorubicin ; analysis ; chemistry ; Electrochemistry ; Electrodes ; Hydrogen-Ion Concentration

Although many studies on the cytotoxicity of the dental cast metal alloys and their components have been carried out, the results are rather conflicting because of the different type of cells used and the various experimental procedures taken. Recently, a number of scientists have claimed that it would be preferable to focus on the use of cells from relevant specific location of the human bodies. Consequently, the primary cultured oral keratinocyte derived from oral mucous along with nickel chloride and several of widely used dental cast base metal alloys(two-Ni-Cr alloys and one Co-Cr alloy)in domestic were selected for this study, from which 1) The amounts of released metal ions were determined using atomic absorption spectrometry, 2) The cytotoxicity of nickel chloride and dental cast base metal alloys was evaluated via MTT assay, and finally, 3) The amounts of released metal ions and the cytotoxicity of nickel chloride were correlated with the cytotoxicity of dental cast base metal alloys And, the results were summarized as follows ; 1. Nickel ion from Ni-Cr alloys and Cobalt ion from Co-Cr alloys resulted in maximum releasing rate during first 24 hours, followed by a decrease in releasing rate with time. Chromium ion were found to be minimal in all alloys. 2. In cytotoxic test, with 40muM, 80muM of nickel chloride, there were observed an increase in the relative cell number compared to control samples after 24 hours. With 160muM, there was found to be no difference in the relative cell number with control, except that 48 hour showed a increase in relative cell number. With 320muM, the relative cell number remained constant and decreased after 48 hours, and with 640muM, a continuing decrease in relative cell number was observed throughout test period. 3. The sensitivity of primary cultured oral epithelium to nickel was lower compared to the cells used in other studies. 4. CB-80 Soft and Regalloy showed no cytotoxicity to primary cultured oral epithelium and New crown resulted in a slight cytotoxicity. In conclusion, it was shown that the primary cultured oral keratinocytes could be applied successfully as testing cells in cytotoxicity test. Futhermore, the dental cast base metal alloys used in this study were found to be biocompatible.
Absorption ; Alloys* ; Cell Count ; Chromium ; Cobalt ; Crowns ; Epithelium ; Human Body ; Humans* ; Ions ; Keratinocytes* ; Nickel ; Spectrum Analysis

BACKGROUND: The exposure of human beings to toxic trace metals continues to be an important public health issue and concern. This study was conducted to assess the exposure to trace metals in the general Korean population by inductively coupled plasma-mass spectrometry (ICP-MS). METHODS: Blood and urine samples were obtained from 175 healthy subjects including those who visited the health promotion center or healthy volunteers. Specimens were collected in special containers and we applied simple sample processing to minimize contamination. We used ICP-MS (Fisons Instrument, Cheshire, UK) to analyze simultaneously the concentration of metals including lead, cadmium, aluminum, cobalt, copper, zinc and selenium. The effects of age, sex and smoking on the trace metal concentrations were also investigated. RESULTS: Distribution of trace metal levels in the general healthy population skewed toward lower values, which reflected low levels of exposure in the general healthy population. The concentrations of some trace metals were significantly affected by age, sex or smoking status. CONCLUSIONS: We performed a simultaneous multielement analysis of biological samples by ICPMS, a reliable and sensitive technique, to build a database of trace metal values in the general population. The results in this study can provide background data for future epidemiological and clinical studies associated with trace metal exposure in the Korean population.
Aluminum ; Cadmium ; Cobalt ; Copper ; Health Promotion ; Healthy Volunteers ; Humans ; Metals ; Public Health ; Selenium ; Smoke ; Smoking ; Spectrum Analysis* ; Zinc

OBJECTIVETo analyze the differential proteomics in human umbilical cord mesenchymal stem cells (MSC) induced by chemical hypoxia-mimetic agent cobalt chloride (CoCl(2)) by two-dimensional gel electrophoresis (2-DE) and mass-spectrometry.

METHODS2-DE was performed to separate proteins from treated and untreated human umbilical cord MSC with CoCl(2). 2-DE images were analyzed by ImageMaster 2D Platinum software 6.0. The differential expressed proteins was identified by MALDI-TOF-MS. The differential proteins were classified based on their functions.

RESULTS2-DE reference patterns of CoCl(2) treated human umbilical cord MSC were established. A total of twenty-six differential proteins were identified, of them eleven proteins were up-regulated and fifteen down-regulated. Their biological functions involved in carbohydrate metabolism, protein metabolism and modification, lipid metabolism, coenzyme and prosthetic group metabolism, cell cycle, immunity and defense, cell structure and motility, signal transduction, protein targeting and localization, neuronal activities, muscle contraction, etc. Peroxiredoxin1 (Prdx) was down-regulated, whereas alpha-enolase (ENO1) and vesicle amine transport protein 1 homolog (VAT1) up-regulated.

CONCLUSIONThe effects of hypoxia on human umbilical cord MSC were participated by multiple proteins and involved in multiple functional pathways.

Cobalt ; pharmacology ; Humans ; Mesenchymal Stromal Cells ; drug effects ; metabolism ; Proteome ; analysis ; Proteomics ; Umbilical Cord ; cytology ; drug effects

OBJECTIVETo investigate the elastic limit and relevant enclasp force of the non-precious metal casting clasp.

METHODSCasting clasp samples of five cobalt-chromium alloys and one 18 - 8 nickel-chromium alloy were made from prefabricated clasp wax by invesing, casting, sandblasting, and ultrasonic cleaning. The process of casting clasp samples deflected by loading and returned by unloading was tested and electric signals were collected by an omnipotent material machine. The analog electric signal was converted to digital signal by an analog to digital converter and stored in a computer. The elastic limit and the relevant enclasp force were analyzed using a relative software.

RESULTSThe elastic limit and the relevant enclasp force of the casting clasp made from the 18 - 8 nickel-chromium alloy were smallest and those of the clasps made from the cobalt-chromium alloys in various brands were different. The range of the elastic limit of the cobalt-chromium alloy casting clasp with the length of 5.0 mm in undercut was 0.28 mm-0.33 mm and the relevant enclasp force was 14.42 g-19.28 g.

CONCLUSIONSIn clinic, we should select the suitable undercut deepness wherein the cobalt-chromium alloy casting clasps, according to different brands of the casting alloy, undercut length, undercut slope, and the clasp thickness.

Chromium Alloys ; Cobalt ; Dental Alloys ; Dental Clasps ; Dental Stress Analysis ; Denture, Partial, Removable ; Elasticity ; Humans ; Nickel ; chemistry ; Stress, Mechanical

OBJECTIVETo study the preserve techniques of squeezed juice of Chinese medicinal materials.

METHODThe techniques of refrigeration, rapid freezing, 60Cogamma-ray sterilization, freeze-drying and spray-drying were used for preservation of squeezed juice of Ginger and Glutinous Rehannia. Different results were compared.

RESULTThe period of preservation was half or one year.

CONCLUSIONThe rapid freezing, freeze-drying and spray-drying are suitable for preservation of squeezed juice of Chinese medicinal materials.

Cobalt Radioisotopes ; Cryopreservation ; Drug Storage ; methods ; Freeze Drying ; methods ; Freezing ; Ginger ; chemistry ; Oils, Volatile ; analysis ; Polysaccharides ; analysis ; Refrigeration ; Rehmannia ; chemistry ; Sterilization

OBJECTIVETo determine the effects of water hardness on the toxicities of cobalt (Co) and nickel (Ni) to a freshwater fish, Capoeta fusca.

METHODSToxicity was investigated by static bioassay. Fish were exposed to cobalt (as CoCl(2)) and nickel (as NiCl(2)) for 96 h in waters with two levels of hardness ("hard" and "very hard", nominally 130 mg/L and 350 mg/L as CaCO(3), respectively).

RESULTSWater hardness had a significant effect on the acute toxicity of both elements. The 96 h LC(50) values for Co were 91.7 mg/L and 204.8 mg/L in hard and very hard waters, respectively, and for Ni the 96 h LC(50) values were 78.0 mg/L and 127.2 mg/L, respectively.

CONCLUSIONThe fish were more sensitive to Co and Ni toxicity in hard water than in very hard water; very hard water protects C. fusca against the toxicity of Co and Ni.

Animals ; Calcium Carbonate ; analysis ; Cobalt ; analysis ; toxicity ; Cyprinidae ; growth & development ; Environmental Monitoring ; Fresh Water ; analysis ; Iran ; Lethal Dose 50 ; Nickel ; analysis ; toxicity ; Toxicity Tests, Acute ; Water Pollutants, Chemical ; analysis ; toxicity

OBJECTIVES: This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. METHODS: A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination (Cdeg), we analyzed the individual contribution of each heavy metal contamination and the overall Cdeg. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. RESULTS: Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall Cdeg. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. CONCLUSIONS: Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and Cdeg, indicating soil contamination in AEPS with the nine heavy metals studied.
Agriculture ; Barium ; Burns ; Cadmium ; Chromium ; Cobalt ; Copper ; Electronic Waste* ; Fluorescence ; Ghana* ; Metals ; Metals, Heavy* ; Nickel ; Recycling* ; Soil* ; Spatial Analysis ; United States Environmental Protection Agency ; Zinc

OBJECTIVEThe objective of this study was to investigate the tarnish induced by Streptococcus sobrinus serotype g on Co-Cr, Ni-Cr and casting titanium alloys.

METHODSCo-Cr, Ni-Co and casting titanium alloys were respectively machined into a size of 10 mm x 10 mm x 1 mm in tablets, and totally 90 specimens with 30 of each were prepared for the test. The 30 specimens of each alloy were randomly and equally divided into three subgroups, including the blank control group, the media control group and the inoculated media group. Under the aerobic condition, the surfaces of the sucrose agar media were inoculated with Streptococcus sobrinus serotype g. The labeled sterile specimens were placed on the surface of the media for 10 weeks. The specimens were changed to a new sucrose media with bacteria each week. The specimens were removed after 10 weeks of incubation, immersed in 0.05% glutaraldehyde solution to eliminate AaY4, rinsed with distilled water. After 2 weeks, the specimens were removed and observed visually or examined by MINOLTA CR-100 color apparatus.

RESULTSCompared with the blank control, the control media without bacteria did not influence the alloy specimens (P > 0.05). Streptococcus sobrinus serotype g caused tarnish on specimens. There was significant difference between the control media group and the blank control group with inoculated media group on all the specimens (P < 0.05).

CONCLUSIONStreptococcus sobrinus serotype g affects the color of Co-Cr, Ni-Cr and casting titanium alloys, but the color does not change from yellow-green range to red-yellow range.

Chromium Alloys ; chemistry ; Cobalt ; chemistry ; Color ; Dental Alloys ; chemistry ; Dental Casting Technique ; Dental Clasps ; Dental Stress Analysis ; Denture Design ; Denture Retention ; instrumentation ; Denture, Partial, Removable ; Materials Testing ; Nickel ; chemistry ; Streptococcus sobrinus ; classification ; physiology ; Surface Properties ; Tensile Strength ; Titanium ; chemistry