Determination of urinary beryllium,arsenic, and selenium in steel production workers

Some of the most pernicious dangers of pollution arise from the presence of traces of toxic elements in the environment. In this work, we report on the determination of beryllium, arsenic, and selenium in the urine of steel production and steel quality control (QC) workers, in comparison to healthy control subjects. The urine samples were digested by a microwave system. Graphite furnace and hydride atomic absorption was used for the quantitative measurements of Be and As and Se, respectively. A quality control method for these procedures was established with concurrent analysis of Standard Trace Metals 7879 Level II and NIST SRM 2670 (Toxic Elements in Freeze Dried Urine). The results show that the urinary levels of these elements in steel production (As, 38.1±28.7 μg/L; Be, 1.58±0.46 μg/L, and Se, 69.2±28.8μg/L) and in quality control workers (As, 23.9±18.1 μg/L; Be, 1.58±0.46 μg/L, and Se, 54.8±25.1 μg/L) are significantly higher than in the controls (As, 10.3±8.7 μg/L; Be, 0.83±0.46 μg/L; and Se, 32.3±13.5 μg/L). The possible connection of these elements with the etiology of disease and the possible role of selenium as a protective agent against the oncogenic and teratogenic action of other substances is discussed. We suggest the need for improvement of environmental conditions in the workplace through better ventilation and industrial hygiene practices.     

Determination of urinary zinc,chromium, and copper in steel production workers

The aim of our investigation was to determine the concentrations of Cu, Zn, and Cr in urine samples under routine clinical laboratory conditions. To asses the reliability of these methods, critical factors such as detection limit(s), calibration range(s), cost, accuracy, and precision were studied. Our method was employed for the quantitative determination of zinc, chromium, and copper in urine samples from steel production and quality control (QC) workers and healthy unexposed controls. After pretreatment with acids, the samples were digested via a microwave oven. Zinc was determined by flame absorption spectrophotometry (FAAS), whereas chromium and copper were determined by a graphite-furnace atomic absorption spectrophotometry (GFAAS). Our results indicate that urinary zinc, chromium, and copper levels of the exposed workers are significantly higher than those of the controls. The possibility that these metals are involved in the etiology of diseases is discussed and recommendations are made to improve workplace ventilation and industrial hygiene practices.     

中药及其水煎液中微量元素含量研究

采用火焰原子吸收光谱法(flame atomic absorption spectrometry,FAAS)测定了黄芪、白术、防风及玉屏风散各次水煎液中铁、铜、锰、铅4种微量元素的含量。结果表明,中药各次水煎液中微量元素的浸出率各不相同,应合理用药,以更好地发挥中药的疗效。     

Evaluation of blood mercury and serum selenium levels in the pregnant population of the Community of Madrid,Spain

BackgroundThe main exposure route to methylmercury (MeHg) is from eating fish and shellfish containing this compound. Since 2004, women of childbearing age in Spain have been urged not to eat some species (eg, tuna, shark, and swordfish), instead choosing low-MeHg seafood as part of a healthy diet.ObjectiveTo describe maternal total blood mercury (THg) and serum selenium (Se) in a cohort of pregnant women living in Spain as it relates to fish intake during the three trimesters and to assess whether or not Spanish women of childbearing age follow the recommendations listed in fish advisories and choose fish species with lower mercury levels.MethodsWe studied 141 female volunteers of childbearing age (16–45 years), interviewing all participants about their overall eating habits and seafood intake. Hg and Se levels were tested using cold-vapor atomic absorption spectrometry (CVAAS) and electrothermal atomic absorption spectrometry (ETAAS), respectively.ResultsAverage THg levels in pregnant women were 2.89 μg/L (standard deviation [SD], 2.75 μg/L, geometric mean [GM], 2.19 μg/L), and THg GM was positively associated with fish intake. Mean Se levels in pregnant women were 73.06 μg/L (SD, 13.38 μg/L), and Se levels were found to increase with tuna intake. In 16 (12%) pregnant women, THg was higher than the level recommended by the U.S. Environmental Protection Agency (EPA) (6.4 μg/L). A positive association was also found between THg and serum Se.ConclusionWomen of childbearing age in Spain had higher THg levels than women in other Western studies. Our study observed that 12% of women had THg levels above the safety limit set by the EPA (6.4 μg/L), and 31% had levels above the relevant benchmark level of 3.5 μg/L suggested by various researchers.     

中药及中药制剂中微量元素铜、铬的含量测定

应用火焰原子吸收光度法(FAAS)对苦参、黄柏及黄柏胶囊中微量元素铜、铬的含量进行了测定,并对FAAS若干条件进行了优化选择。结果表明,该法的平均回收率在95.2%～104.8%之间,相对标准偏差在1.76%以下,结果可靠,方法简便,可用于实际样品的测定。     

Determination of trace elements in some natural drugs by atomic absorption spectrometry

Fifteen kinds of common plants, animals, and minerals used as traditional medicines by the Chinese people have been subjected to analysis by atomic absorption spectrometry for its content of seven metals: lead, cadmium, arsenic, mercury, copper, cobalt, and manganese. The concentrations of these elements are significantly different according to their vegetal, animal, or mineral origin. The average values found for lead, cadmium, arsenic, cobalt, and manganese in drugs of mineral origin are higher than those derived from plants and animals, except for copper, which was higher in drugs of animal origin. Our results suggest that the user of traditional Chinese crude drugs should be warned of the potential danger of heavy-metal poisoning because their concentrations seem to be higher than the maximum values allowed by health agencies in several countries.     

Studies on some trace and minor elements in blood

Blood is one of the widely used specimens for biological trace element research because of its biological significance and ease of sampling. We have conducted a study of the blood of the Kalpakkam township population for trace and minor elements. For this purpose, analytical methods have been developed and standardized in our laboratory for the elemental analysis of blood plasma and red cells. Inductively coupled plasma-mass spectrometry (ICP-MS), a relatively new technique, has been applied for the analysis of trace elements. Details regarding spectral interference and matrix interference encountered in the analysis of blood and the methods of correcting them have been discussed. Flame atomic absorption spectrometry (AAS)/atomic emission spectrometry (AES) has been applied for the determination of minor elements. Precision and accuracy of these methods have also been discussed.     

Determination of selenium in the human brain by graphite furnace atomic absorption spectrometry

For the investigation of neurological disorders, a development of simple and accessible methods for determining selenium in human brain samples is required. We devised a method of determining selenium using graphite furnace atomic absorption spectrometry (GFAAS). An electrodeless discharge lamp provided the sufficient sensitivity to determine brain selenium. The matrix interferences were avoided by using high temperature, a prolonged pyrolysis step, and a palladium matrix modifier. The technique of standard addition was used to evaluate the sample concentrations. The accuracy of the method was confirmed by a bovine liver reference material. The detection limit of selenium was 0.04 ng. The determined selenium concentrations of human brain cortex and white matter were higher than those of putamen (115–155 and 206–222 ng/g wet wt, respectively). These GFAAS values agreed with those obtained by fluorometric analysis (r=0.91,n=10). Moreover, the GFAAS values were compatible to those reported by other researchers (99–274 ng/g wet wt), in which selenium concentrations in putamen also tended to be higher than the other two regions. We conclude that GFAAS is useful for selenium analysis in brain samples.     

Whole-body retention,and urinary and fecal excretion of mercury after subchronic oral exposure to mercuric chloride in rats

The effects of long-term daily intake of mercury on its urinary and fecal excretion, whole-body retention, and blood concentration in male rats were observed. The animals were exposed to mercuric chloride labeled with ²⁰³Hg via drinking water for 8 weeks (5, 50 and 500 m Hg). ²⁰³Hg in urine, feces and blood was quantified. The blood mercury concentration did not keep a linear relationship with the increasing dose. The percentage of the total amount of mercury intake which is excreted by the fecal route in rats exposed to 500 m Hg was significantly lower than in those exposed to 5 and 50 m. The daily dose percentage of mercury excreted in urine increased with dose size. The results show that the absorption fraction of mercury through the gastrointestinal tract (30–40%) was higher than values previously reported.     

Evaluation of methods for total selenium determination in yeast

The selenium determination in biological materials by the classical fluorometric method (FM) is time-consuming and also hazardous, as it requires the destruction of the organic matrix samples with hot HNO₃/HClO₄ mixtures prior to analysis. Accordingly, commercial analytical laboratories are increasingly using faster instrumental methods; for sample digestion, avoid using HClO₄. Because of these procedural changes, the results obtained by commercial laboratories may be unreliable, especially for samples containing Se in organic forms. One such “difficult” substrate is Se yeast, which contains most of its Se as selenomethionine. To establish which methods for Se analysis and sample digestion are applicable, samples of Se yeast and of selenomethionine standards were sent to laboratories employing either flame atomic absorption spectrometry (FAAS), inductively coupled plasma-mass spectrometry (ICP-MS), or hydride generation atomic absorption spectrometry (HGAAS). The result were compared with those obtained by FM and non-destructive instrumental neutron activation analysis (INAA). ICP-MS, after microwave digestion of sample with HNO₃/H₂O₂, produced results within 5% of the expected values, as did those obtained by FM and INAA. With FAAS, acceptable results were obtained after digestion with HNO₃/HCl. With HGAAS, sample digestion with HNO₃/H₂O₂ produced values that were systematically elevated by about 10% and exhibited standard deviations of ≥10%. Thus, current methods of sample digestion are applicable for Se yeast analysis by ICP-MS and FAAS, but not by HGAAS.     

Chromium,nickel, and arsenic determinations in human samples by thermal and epithermal neutron activation analyses

Both thermal and epithermal neutron activation analyses have been employed to determine chromium and nickel in lung tissue and arsenic in urine. Based on accuracy, precision, and detection limits, these techniques have been successfully used to analyze lung tissue from a deceased welder, who died, from cancer, and to paratake in an interlaboratory toxicological urine program.     

Subcellular distribution of aluminum, bismuth, cadmium, chromium, copper, iron, manganese, nickel, and lead in cultivated mushrooms (Agaricus bisporus and Pleurotus ostreatus)

In this work, the distribution of nine metals in two types of cultivated mushroom had been investigated. For Agaricus bisporus, the biomass was separated into caps and stalks, and for Pleurotus ostreatus, the entire mushrooms were taken for analysis. Electrothermal atomic absorption spectrometry was used for total element determination in acid digests. For accuracy checking, the certified reference material (NIST 1571, citrus leaves) was analyzed. The results obtained for the two fungi species were within the ranges of concentration reported previously by other authors. Subcellular fractionation was accomplished by centrifugation of cell homogenates, which has been suspended in Tris-HCl buffer. In the first centrifugation (7300g, 4°C, 10 min), cell walls were separated (pellet I), and the second centrifugation (147,000g, 4°C, 60 min) yielded mixed membrane fraction (pellet II) and cytosol (supernatant II). Recoveries of the fractionation procedure were in the range 70–100% (with the exception of Fe). For all elements studied, the highest relative contributions were found in cytosol fractions of the fruiting bodies (63–72%, 49–76%, 44–93%, 26–87pc, 55–85%, 50–68%, 41–78%, 39–78%, 54–67% respectively for Al, Bi, Cd, Cr, Cu, Fe, Mn, Ni, and Pb. Lower contributions were found in cell walls (respectively 22–32%, 24–44%, 6.1–47%, 12–52%, 7.3–37%, 7.9–32%, 19–52%, 20–42%, and 25–38%) and only minute amounts in the mixed membrane fraction (3.0–5.8%, 0.7–7.0%, 0.7–8.3%, 1.0–22%, 7.5–14%, 16–24%, 1.1–19%, and 5.1–7.7%). The results obtained indicate that small water-soluble molecules were the primary forms of nine elements in two mushroom species studied. On the other hand, the evidence has been provided on elements binding to larger, water-insoluble molecules contained in the structures of cell wall and membranes. The relative distribution was both element and fungi dependent. Thus, in P. ostreatus, total element levels were higher than in A. bisporus, with the preference for their accumulation in cytosol. On the contrary, total element content in the latter fungi was lower; however, a clear tendency toward more efficient element incorporation to the water-insoluble structures was observed (no apparent differences between stalks and caps). These findings might contribute in a better understanding of the accumulation of metals in mushrooms.     

Multivessel system for cold-vapor mercury generation determination of mercury in hair and fish

A multivessel system for the determination of mercury (Hg) by cold-vapor atomic absorption spectrometry (CV-AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) was developed. The performance of the proposed device was tested by determining total Hg in quality-control samples of hair and fishes following acid digestion. Application of the apparatus to the determination of Hg by CV-AAS following alkaline digestion was studied as well. The detection limit obtained for CV-AAS was 0.11 ng/mL and for ICP-AES 1.39 ng/mL. The results show that the system is appropriate to be used in techniques involving cold-vapor generation of Hg.     

Serum levels of selenium, manganese, copper, and iron in colorectal cancer patients

This article describes a study in which four trace elements (Se, Mn, Cu, and Fe) were analyzed in the blood serum of the patients with colorectal cancer from the Moravian region of the Czech Republic. Atomic absorption spectrometry with graphite furnace atomization was used for analysis of selenium and manganese and with flame atomization for analysis of copper and iron. The observed serum concentrations in adenocarcinoma colorectal patients of selenium were significantly lower (41.8 ± 11.6 μg/L) and those of manganese (16.3 ± 4.5 μg/L) and iron (2.89 ± 1.23 mg/L) were significantly higher as compared to the age-matched control group. Copper serum content (0.95 ± 0.28 mg/L) did not significantly differ as compared to healthy population.     

微波消解－火焰原子吸收光谱法测定蜂胶中金属元素含量

目的：测定一种原产地为加拿大的蜂胶中金属元素的含量,为进一步研究蜂胶营养价值提供数据,同时改进测量方法。方法：用微波消解法处理样品,用硝酸和过氧化氢的混合物作为消解剂进行微波消解,并优化消解条件,然后用火焰原子吸收光谱法测定蜂胶制品中钙、铁、镁、锌、钠、钾、铜的含量。结果：七种元素相对标准偏差为O．85％～2．33％（n=7）,回收率在96．5％～104．7％之间。试验结果表明该蜂胶中含有丰富的金属元素,且与河南产蜂胶相比,加拿大产蜂胶中多种金属元素含量远低于河南产蜂胶。结论：使用本文方法测定蜂胶中的金属元素含量,结果准确,方法可靠。为进一步探讨蜂胶制品金属元素与其保健功能的关系提供了有用数据。     

微波消解- 火焰原子吸收光谱法测定蜂胶中金属元素含量

目的:测定一种原产地为加拿大的蜂胶中金属元素的含量,为进一步研究蜂胶营养价值提供数据,同时改进测量方法。方法:用微波消解法处理样品,用硝酸和过氧化氢的混合物作为消解剂进行微波消解,并优化消解条件,然后用火焰原子吸收光谱法测定蜂胶制品中钙、铁、镁、锌、钠、钾、铜的含量。结果:七种元素相对标准偏差为0.85%~2.33%(n=7),回收率在96.5%~104.7%之间。试验结果表明该蜂胶中含有丰富的金属元素,且与河南产蜂胶相比,加拿大产蜂胶中多种金属元素含量远低于河南产蜂胶。结论:使用本文方法测定蜂胶中的金属元素含量,结果准确,方法可靠。为进一步探讨蜂胶制品金属元素与其保健功能的关系提供了有用数据。     

Essential trace elements in humans

Serum arsenic concentrations of persons suffering from renal failure and undergoing hemodialysis treatment (n=85) and of healthy controls (n=25) were determined by hydride-generation AAS technique after microwave digestion. The results were evaluated by comparing the values of both groups, considering physiological factors and individual data, as well as comorbid conditions of the hemodialysis (HD) patients. Serum arsenic levels were diminished in the patient group compared with controls (mean values 8.5±1.8 ng/mL vs 10.6±1.3 ng/mL). Furthermore, additional diseases within the hemodialysis group, particularly injuries of the central nervous system (CNS), vascular diseases, and cancer, were correlated to occasionally markedly decreased serum arsenic concentrations. It was concluded that arsenic homeostasis is disturbed by HD treatment and certain additional diseases. Desirable arsenic concentrations in the body seem to be reasonable. This consideration results in the conclusion that arsenic could play an essential role in human health. Thus, reference arsenic concentrations in different human tissues and body fluids should be established in order to recognize not only arsenic intoxication, but also arsenic deficiency. Perhaps arsenic deficiency contributes to the increased death risk of HD patients, and therefore, arsenic supplementations for patients with extremely low serum arsenic concentrations should be taken into account.     

Determination of zinc, copper, lead and cadmium in some medicinally important leaves by differential pulse anodic stripping analysis

Levels of zinc, copper, lead and cadmium have been determined in some medicinally important leaves by differential pulse anodic stripping voltammetry (DPASV). High pressure digestion with nitric acid (HPA) was used for sample digestion. The accuracy of the method was verified by the parallel analysis of leaves with inductively coupled plasma atomic emission spectroscopy (ICP-AES) and recovery studies by the analysis of standard reference materials. Based on elemental levels the utility of these leaves in medicine are discussed. Statistical treatment has been used in order to understand the correlation between elements in these leaves.     

Determination of copper in different chloroplast preparations

The determination of total Cu is not often correlated with states of deficiency in plant material. This fact makes it necessary to look for biologically active Cu. Suspensions of thylakoid membranes and photosystem II particles, properly diluted with 13 mM nitric acid, were used for this purpose. The presence of a minute quantity of an antifoaming agent, such as 1-octanol, is essential when an aliquot of the slurry is injected into the graphite furnace of the atomic absorption spectrophotometer. Good agreement was obtained between our results and those obtained by a classical dry combustion method. Reproducibility was better than 5% when expressed as relative standard deviation.     

Serum selenium levels in healthy slovak children and adolescents

Blood serum selenium levels were measured in 891 healthy children and adolescents (aged 11–18 yr, 450 girls and 441 boys) residing in both rural and urban areas from eight regions of Slovakia. Subjects were divided into four age groups (11–12 y, 13–14 y, 15–16 y, and 17–18 y). Serum selenium concentration was determined by the electrothermal atomic absorption spectrometric method. The mean (±SD) serum selenium concentrations were 0.750 ±0.255 μmol/L in girls and 0.773 ±0.235 μmol/L in boys. A large proportion of the individuals (25.7% in girls, 18.1% in boys) exhibited serum selenium levels under 0.57 μmol/L (45 μg/L). An increasing trend of the serum selenium values with age has been observed in both boys (p < 0.01) and girls (p < 0.05). Boys had higher serum selenium levels in the all age groups but the differences were not statistically significant.