[Determination of trace gallium by graphite furnace atomic absorption spectrometry in urine]

OBJECTIVE

To establish a method for determination trace gallium in urine by graphite furnace atomic absorption spectrometry (GFAAS).

METHODS

The ammonium dihydrogen phosphate was matrix modifier. The temperature effect about pyrolysis (Tpyr) and atomization temperature were optimized for determination of trace gallium. The method of technical standard about within-run, between-run and recoveries of standard were optimized.

RESULTS

The method showed a linear relationship within the range of 0.20~80.00 μg/L (r=0.998). The within-run and between-run relative standard deviations (RSD) of repetitive measurement at 5.0, 10.0, 20.0 μg/L concentration levels were 2.1%~5.5% and 2.3%~3.0%. The detection limit was 0.06 μg/L. The recoveries of gallium were 98.2%~101.1%.

CONCLUSION

This method is simple, low detection limit, accurate, reliable and reproducible. It has been applied for determination of trace gallium in urine samples those who need occupation health examination or poisoning diagnosis.

Determination of gallium in human urine by supercritical carbon dioxide extraction and graphite furnace atomic absorption spectrometry

This study presents supercritical carbon dioxide (scCO(2)) extraction as an inherently safer and cleaner sample treatment method for identifying trace gallium in urine samples. Extraction is performed in the presence of a fluorinated beta-diketones chelating agent, 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (HFOD), by unmodified scCO(2). Quantitative extractions are conducted at 80 degrees C and 20.7 MPa with 15 min static plus 15 min dynamic extractions, and are followed by analysis via graphite furnace atomic absorption spectroscopy (GFAAS). The proposed procedure is successfully applied to determine the concentrations of gallium in real urine samples spiked with various levels of gallium with satisfactory recoveries of 90.8-100.3% (n=6) and relative standard deviations <10%. A standard reference material (SRM), Seronorm Trace Elements Urine, is used to validate the accuracy of the proposed method.

Lipid peroxidation in workers exposed to aluminium, gallium, indium, arsenic, and antimony in the optoelectronic industry

OBJECTIVE

The objective of this study was to investigate whether exposure to aluminum, gallium, indium, arsenic, and antimony induces lipid peroxidation in humans.

METHODS

Whole blood and urine levels of 103 exposed electronic industry workers and 67 referents were analyzed by use of inductively coupled plasma mass spectrometry. Malondialdehyde (MDA), the product of lipid peroxidation, was determined by high-performance liquid chromatography.

RESULTS

The mean plasma MDA level in the 103 workers was significantly higher than that in 67 referents. The levels of MDA in the exposed workers were correlated significantly with the levels of urinary gallium and arsenic.

CONCLUSIONS

Malondialdehyde as an index of lipid peroxidation can be induced by gallium and arsenic exposure. By reducing exposure to these metals, biologic effects such as lipid peroxidation may also be diminished.

Biological monitoring of exposures to aluminium, gallium, indium, arsenic, and antimony in optoelectronic industry workers

The main objective of this study was to investigate aluminum, gallium, indium, arsenic, and antimony exposures on blood and urine levels in the optoelectronic workers. One hundred seventy subjects were enrolled in this cohort study. Whole blood and urine levels were determined by inductively coupled plasma-mass spectrometry. Blood indium and urine gallium and arsenic levels in the 103 workers were significantly higher than that in 67 controls during the follow-up period. In regression models, the significant risk factors of exposure were job title, preventive equipment, Quetelet's index, sex, and education level. The findings of this study suggest that gallium, indium, and arsenic exposure levels may affect their respective levels in blood and urine. The use of clean, preventive equipment is recommended when prioritizing the administration of safety and hygiene in optoelectronics industries.

Alkylaryl-amino derivatives of 3-hydroxy-4-pyridinones as aluminium chelating agents with potential clinical application

The neurotoxicity of aluminium is well established and so strategies for suitable aluminium chelating therapies, aimed at the treatment and/or amelioration of some neurological disorders, are of current interest. The present work describes a set of new bifunctional compounds containing a 3-hydroxy-4-pyridinone (3,4-HP) unit, as the aluminium chelating moiety, which is extra-functionalised with different alkyl-arylamine molecular segments, to account for the improvement on the biodistribution specificity of the chelating agents or the corresponding complexes. Besides the synthetic scheme, studies are performed to assess the properties of these compounds, namely in terms of lipophilicity, Al-chelating ability, speciation and in vivo 67Ga biodistribution. These studies show that the extrafunctional groups fortunately have small effects on the high Al chelating affinity of the 3,4-HP units, over a wide range of pH, but they lead to favourable changes on the lipo-hydrophilic balance of the ligands and on the complex speciation. Differences found in the biodistribution, namely the decrease of the blood-clearance rate and increase of the bone retention or the hepatobiliary excretion, seem to be mostly rationalized in terms of the increasing lipophilic character of the ligands.

Preparation of urine samples for trace metal determination: a study with aluminium analysis by inductively coupled plasma optical emission spectrometry

Urinary analysis of trace metals forms a significant role in clinical chemistry, but the optimal preparation and analysis of urine samples has not been investigated. Human urine is generally supersaturated with dissolved solids. Therefore, samples often precipitate following collection. X-ray microanalysis showed that this precipitate was predominantly rich in calcium and phosphorus but could include some trace metals from urine, potentially lowering their concentrations in solution. Hence, the precipitate must be fully redissolved for accurate analysis of trace metals in urine. Methods are emphasized for the best collection and preparation of urine samples for subsequent trace metal analysis; in this work inductively coupled plasma optical emission spectrometry (ICPOES) was used for the analysis of aluminium. For optimal accuracy, peak profiles were collected over 396.147 nm-396.157 nm. Urinary aluminium levels were investigated from 10 healthy volunteers and concentrations were obtained using either aqueous, pooled or individual urine-based standard curves. Since urine has a highly variable matrix, individual sample-based standards, which are unique to that particular sample, gave the most accurate results. However, where sample size is small or sample numbers are unfeasibly large, pooled sample-based standards give good approximations to within 15% and, with appropriate validation, other elements as internal standards could also be used for approximations. Aqueous standards should be avoided. Spike-recovery experiments confirmed these data since individual sample based standards showed optimal recovery [99.3 (4.4)%], while pooled sample-based standards were a close proxy [101.6 (9.2)%] but aqueous standards were inappropriate [137.4 (12.8)%]. Postprandial urinary aluminium levels of the 10 volunteers were [7.2 (3.7)micrograms/L] after analysis using individual sample-based standard curves.

Rapid excretion of gallium-67 isotope in an iron-overloaded patient receiving high-dose intravenous deferoxamine

A 23 year-old black male with homozygous sickle cell disease (Hb SS disease) and transfusional iron overload was admitted for evaluation of response to intravenous deferoxamine (DFO) therapy. Soon after admission, the patient suffered an intraventricular hemorrhage and during his subsequent hospitalization developed a persistent fever of undetermined origin (f.u.o.). Included in the diagnostic evaluation of fever was a gallium 67 scan (Ga-67), which was initially nondiagnostic because of Ga-67 citrate's preferential chelation by DFO. After DFO was discontinued, a repeat scan demonstrated a lesion above the left kidney. To our knowledge the unusual interaction in vivo of DFO with Ga-67 citrate has not been reported in the clinical literature. With the anticipated increased use of chelation therapy for patients with transfusional iron overload, this interaction may be encountered more frequently. DFO should be discontinued before the use of Ga-67 scanning in this clinical situation, or an alternative isotopic scan, such as indium-labelled white cells, should be considered.

Metabolism and excretion of orally and intraperitoneally administered gallium arsenide in the hamster

This study deals with the metabolism of gallium arsenide (GaAs). GaAs was shown to be soluble in various media. Since this compound could dissolve in aqueous solvents, in vivo dissolution was investigated. Hamsters were used to study the dissolution and subsequent pharmacokinetics of any liberated arsenic species. The fecal and urinary excretion data following oral and intraperitoneal administration showed that GaAs, when administered orally, is mostly excreted in the feces but poorly in the urine, and that the compound, when administered intraperitoneally, is poorly excreted in both the feces and urine. Analysis of tissues for arsenic levels yielded concentrations in the ppb range, which further verified this fact. Most interesting was the fact that dimethylarsinic acid (DMAA) and methylarsonic acid (MAA) along with inorganic arsenic were found in the urine and tissues. GaAs was shown to dissolve in vivo and the released arsenic species were metabolized as other inorganic arsenics were found in the urine and tissues. GaAs was shown to dissolve in vivo and the released arsenic species were metabolized as other inorganic arsenic containing compounds. The low solubility and poor oral absorption may make this compound less toxic than other inorganic arsenic compounds.

Flameless atomic absorption spectrometry determination of gallium in biological materials

The application of flameless atomic absorption spectrophotometry to the quantitation of gallium in urine, serum and tissues is described. The method can be used to detect gallium concentrations as low as 100--200 ppb in fluids and tissues. Significant interference with the gallium atomization signal was caused by CaCl2; however, the interference could be completely prevented by using the chelating agent EDTA. This method makes feasible the quantitative determination of the pharmacokinetic parameters of gallium administration as an anticancer drug in animals and humans.

Distribution of anticancer agents in spontaneous animal tumors. II. Distribution of gallium in canine lymphosarcoma

The physiologic disposition of pharmacologic doses of gallium was studied in control dogs and dogs with spontaneous lymphosarcoma. Gallium 67 (67Ga) was administered iv with carrier gallium added at a dose of 8 mg/kg. About 50% of the injected dose was excreted in the urine by 48 hours (mostly in the first 12 hr), whereas negligible amounts were excreted in bile. The distribution of 67Ga in normal tissues was similar in control and tumor-bearing dogs. The tissue-to-plasma concentrations of gallium were considerably greater than 1 in the kidney cortex, bone marrow, bone, small intestine, and liver 6-72 hours after administration of the drug. At comparable time periods, tissue-to-plasma ratios of gallium were less than 1 in skeletal muscle and brain. In dogs with lymphosarcoma there was neither selective uptake nor selective retention of gallium in comparison to most normal tissues. In fact, several normal tissues, particularly kidney cortex and bone marrow, concentrated gallium greatly in excess of tumors. Qualitatively similar findings were obtained in a dog with malignant melanoma. These findings were contrary to what one would predict from reports showing that carrier-free 67Ga is selectively concentrated in various human and animal tumors. This indicates the need for more extensive studies of the physiologic disposition of pharmacologic (antitumor) doses of gallium in humans and appropriate animal models.