首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
BackgroundHuman biomonitoring studies of trace elements in biological fluids are mostly limited to a certain number of elements or biological materials. In this study, we describe the significant extension of a biomonitoring to 73 elements being present in concentration ranges from ng/L to g/L in clinically relevant specimens such as blood, serum, erythrocytes and urine.MethodsThe samples were collected from 102 occupationally non-exposed inhabitants of northern Germany. The elements were determined either by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) in the low concentration range or by inductively coupled plasma optical emission spectrometry (ICP-OES) for essential trace elements and electrolytes.ResultsMean values and selected percentiles of element concentrations are presented for all sample materials. From the results, we calculated the distribution of elements between plasma and blood cells. Application of ICP-MS/MS improves selectivity and accuracy in the determination of elements that are strongly spectrally interfered, such as Cr, Ge, Pd or Ti in blood samples.ConclusionsThis publication provides very valuable information for occupational or environmental hygienists, toxicologists and clinical chemists due to the particularly high number of determined elements and presented concentration ranges.  相似文献   

2.
Introduction – To ensure food safety, accurate knowledge of the levels of several trace elements is necessary. This is also true for natural products of plants and resins used for human consumption or therapeutic treatment, like the mastic gum of Pistacia lentiscus. The rapid analysis of gum and resin matrices is a challenge because there are problems with the decomposition of such complicated matrices. Objective – To develop an efficient multielemental analytical method for the determination of trace elements and to compare different procedures for analyte extraction when microwave‐assisted digestion is applied. Methodology – The inductively coupled plasma atomic emission spectrometric (ICP‐AES) technique was applied and the optimum ICP conditions like radiofrequency power, argon flow rate and nebuliser sample uptake flowrate were found. The microwave‐assisted procedure was compared with that with conventional heating. Since mastic and resinous materials are difficult for dissolution and extraction of trace element, influential acid mixtures containing hydrofluoric acid proved to be capable of quantitative extraction of the analytes. Results – The digestion of mastic resin or similar matrices is significantly facilitated by using microwave radiation instead of conventional heating since the obtained recovery for several analytes is much higher. It was proved that the acid mixture of HCl–HNO3–HF was the most efficient for complete sample digestion and recovery of the analytes. Conclusions The performance characteristics of the developed method were evaluated against certified reference material and the method was proved reliable and applicable to the analysis of mastic gum and possibly to similar resinous matrices. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

3.
A poly (methacrylic acid-ethylene glycol dimethacrylate, MAA-EGDMA) monolithic capillary was used for the in-tube solid-phase microextraction (in-tube SPME) of several angiotensin II receptor antagonists (ARA-IIs) from human plasma and urine. Under the optimized extraction condition, the protein component of the biological sample was flushed through the monolithic capillary, while the analytes were successfully trapped. Coupled to HPLC with fluorescence detection, this on-line in-tube SPME method was successfully applied for the determination of candesartan, losartan, irbesartan, valsartan, telmisartan, and their detection limits were found to be 0.1-15.3ng/mL and 0.1-15.2ng/mL in human plasma and urine, respectively. The method was linear over the range of 0.5-200ng/mL for telmisartan, 5-2000ng/mL for candesartan and irbesartan, 10-2000ng/mL for valsartan, and 50-5000ng/mL for losartan with correlation coefficients being above 0.9985 in plasma sample and above 0.9994 in urine sample. The method reproducibility was evaluated at three concentration levels, resulting in the R.S.D. <7%. The poly (MAA-EGDMA) monolithic capillary was demonstrated to be robust and biocompatible by using direct injections of biological samples.  相似文献   

4.
A method is described for the determination of residues of the antibiotic chloramphenicol in biological samples. The method is based on gas chromatography/negative ion chemical ionization mass spectrometry and uses (37Cl2)chloramphenicol as internal standard. Selective ion monitoring of four analyte-specific ions enables the determination of chloramphenicol levels in urine of 3 micrograms l-1 with a coefficient of variation of 8%. The limit of detection of the method is 0.1 p.p.b. for urine, muscle and egg.  相似文献   

5.
Lobinski R  Moulin C  Ortega R 《Biochimie》2006,88(11):1591-1604
Mineral elements, often at the trace level, play a considerable role in physiology and pathology of biological systems. Metallogenomics, metalloproteomics, and metallomics are among the emerging disciplines which are critically dependent on spatially resolved concentration maps of trace elements in a cell or tissue, on information on chemical speciation, and on that on metal-binding coordination sites. The mini-review discusses recent progress in analytical techniques for element profiling on the genome scale, biological trace element imaging, and probing, identification and quantification of chemical species in the biological environment. Imaging of the element distribution in cells and tissue sections is becoming possible with sub-micrometer spatial resolution and picogram-level sensitivity owing to advances in laser ablation MS, ion beam and synchrotron radiation X-ray fluorescence microprobes. Progress in nanoflow chromatography and capillary electrophoresis coupled with element specific ICP MS and molecule-specific electrospray MS/MS and MALDI enables speciation of elements in microsamples in a complex biological environment. Laser ablation ICP MS, micro-SXRF, and micro-PIXE allow mapping of trace element distribution in 1D and 2D proteomics gels. The increasing sensitivity of EXAFS and XANES owing to the use of more intense synchrotron beams and efficient focusing optics provide information about oxidation state, fingerprint speciation of metal sites and metal-site structures.  相似文献   

6.
While biodegradable, biocompatible polyesters such as poly (lactic-co-glycolic acid) (PLGA) are popular materials for the manufacture of tissue engineering scaffolds, their surface properties are not particularly suitable for directed tissue growth. Although a number of approaches to chemically modify the PLGA surface have been reported, their applicability to soft tissue scaffolds, which combine large volumes, complex shapes, and extremely fine structures, is questionable. In this paper, we describe two wet-chemical methods, base hydrolysis and aminolysis, to introduce useful levels of carboxylic acid or primary and secondary amine groups, respectively, onto the surface of PLGA with minimal degradation. The effects of temperature, concentration, pH, and solvent type on the kinetics of these reactions are studied by following changes in the wettability of the PLGA using contact angle measurements. In addition, the treated surfaces are studied using X-ray photoelectron spectroscopy (XPS) to determine the effect on the surface chemical structure. Furthermore, we show using XPS analysis that these carboxyl and amine groups are readily activated to allow the covalent attachment of biological macromolecules.  相似文献   

7.
Interest in the biological behavior of a growing number of elements, along with increasing recognition of the importance of interactions among them, demands a versatile and reliable technique for multielement analysis of biological samples. Significant improvements over the sensitivity achieved with conventional inductively coupled plasma (ICP) optical emission spectrometries have been realized with the introduction of quadrupole mass spectrometry (MS) for detection of ions in the plasma. The hybrid technique of ICP-MS promises to be a method of rapid multielement analysis, at detection limits that approach or surpass those of other technologies. However, the application of ICP-MS to analyses of biological interest is truly in its infancy. Here we report the use of ICP-MS for the determination of more than 30 elements of biological interest in a tissue and a biological fluid (rat liver and serum, respectively). Experimental values of the elements serve as a basis for discussion of analytical protocols, performance criteria, and certain problems peculiar to ICP-MS.  相似文献   

8.
Optoacoustic spectroscopy is a potentially powerful tool for the determination of trace and ultratrace components of biochemical interest. We derive here an abbreviated theory of pulsed optoacoustic spectroscopy, describe the experimental apparatus, and report on the performance in the determination of NADH. Results are consistent with theory over the concentration range 1 × 10?5 to 5 × 10?7, m. A projected lower limit for detection is 1 × 10?8, m. Possible applications to the study of nucleotide interactions are discussed.  相似文献   

9.
The merits of radiochemical neutron activation analysis (RNAA) and inductively coupled plasma mass spectrometry (ICP-MS) are critically discussed for the determination of trace and ultratrace elements in normal human serum. For RNAA, two semiautomated procedures, allowing the determination of up to 18 elements, are briefly described. ICP-MS has a series of interesting features for the determination of trace elements. Matrix and spectral interferences can mostly be avoided or corrected for. After a simple 5- or 10-fold dilution and addition of an internal standard, more than 20 elements can be measured precisely and accurately.  相似文献   

10.
It has been speculated that trace elements may play a role in the pathogenesis of heart diseases In the present study, we aimed to access the levels of chromium (Cr) and manganese (Mn) in biological samples (whole blood, urine, and scalp hair) of myocardial infarction (MI) patients of both gender age ranged (45?C60?years) at first, second, and third heart attack (n?=?130), hospitalized in cardiac ward of National Hospital of Hyderabad city (Pakistan). For comparison, healthy age-matched referent subjects (n?=?61), of both gender were also selected. The Cr and Mn in biological samples were measured by electrothermal atomic absorption spectrometry, prior to microwave-assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. During this study, 78% of 32 registered patients of third MI attack (aged >50?years) were died. In these subjects the concentration of Cr and Mn were decreased by 24.7% and 19.8% in scalp hair, while in blood samples 17.9% and 12.4%, respectively, as compared to those who tolerated third MI attack (p?=?0.063). Although these data do not prove a causal relationship, these results are consistent with the hypothesis that heart disease may cause deficiencies of certain essential trace elements. The excretion levels of Cr and Mn in urine samples of first MCI were higher than controls at p values (0.029 and 0.011), respectively, whereas the excretion rates of both elements were further enhance after second myocardial infarction attack. The Cr and Mn concentration was inversely associated with the risk of myocardial infarction attacks in both genders. These results add to an increasing body of evidence that, Cr and Mn are importance for cardiovascular health.  相似文献   

11.
The determination of essential trace and toxic elements in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible effects of environmental exposure on paralysed male workers (n?=?75) belonging to the production and quality control departments of a steel mill. In this investigation, the concentrations of arsenic, cadmium, lead, manganese and zinc were determined in biological samples (blood, urine and scalp hair samples) of exposed paralysis and non-paralysed steel mill workers. For comparative purposes, unexposed healthy subjects of same age group were selected as referents. The elements in the biological samples were measured by atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. The results indicate that the level understudy elements in all three biological samples were significantly higher in paralysed workers of both groups (quality control and production) as compared to referents (p?相似文献   

12.
Impedance spectroscopy approaches combined with the immunosensor technology have been used for the determination of trace amounts of ciprofloxacin antibiotic belonging to the fluoroquinolone family. The sensor electrode was based on the immobilization of anti-ciprofloxacin antibodies by chemical binding onto a poly(pyrrole-NHS) film electrogenerated on a solid gold substrate. The electrode surface was modified by electropolymerization of pyrrole-NHS, antibody grafting and ciprofloxacin immunoreaction. The sensitive steps of surface modification, cyclic voltammetry (CV) and atomic force microscopy (AFM) imaging have been used for electrode surface characterization. The immunoreaction of ciprofloxacin on the grafted anti-ciprofloxacin antibody directly triggers a signal via impedance spectroscopy measurements which allows the detection of extremely low concentration of 10 pg/ml ciprofloxacin.  相似文献   

13.
Recent studies from the author’s laboratory indicated that camel urine possesses antiplatelet activity and anti-cancer activity which is not present in bovine urine. The objective of this study is to compare the volatile and elemental components of bovine and camel urine using GC–MS and ICP–MS analysis. We are interested to know the component that performs these biological activities. The freeze dried urine was dissolved in dichloromethane and then derivatization process followed by using BSTFA for GC–MS analysis. Thirty different compounds were analyzed by the derivatization process in full scan mode. For ICP–MS analysis twenty eight important elements were analyzed in both bovine and camel urine. The results of GC–MS and ICP–MS analysis showed marked difference in the urinary metabolites. GC–MS evaluation of camel urine finds a lot of products of metabolism like benzene propanoic acid derivatives, fatty acid derivatives, amino acid derivatives, sugars, prostaglandins and canavanine. Several research reports reveal the metabolomics studies on camel urine but none of them completely reported the pharmacology related metabolomics. The present data of GC–MS suggest and support the previous studies and activities related to camel urine.  相似文献   

14.
Summary Standards were prepared for quantitative X-ray microanalysis of the halogen elements Cl, Br and I in sections of resin embedded biological specimens. Halogenated aromatic compounds were dissolved in resin, which subsequently was polymerized. Homogeneity and stability of the standards were determined and found to be satisfactory. A general procedure of calculation of elemental concentrations according to the continuum method is given for the case that the specimen contains appreciable concentrations of one or more rather heavy elements. It is shown that use of approximations may lead to unacceptable errors, even in the concentration ranges occurring in biological specimens. As a practical application, the concentration of bromine in the chloroplasts of the red alga Chondrus crispus was determined quantitatively. The inner cells contained more bromine than the epidermal cells: in the chloroplasts of the inner cells bromine concentrations of about 6% could be demonstrated.  相似文献   

15.
Standards were prepared for quantitative X-ray microanalysis of the halogen elements Cl, Br and I in sections of resin embedded biological specimens. Halogenated aromatic compounds were dissolved in resin, which subsequently was polymerized. Homogeneity and stability of the standards were determined and found to be satisfactory. A general procedure of calculation of elemental concentrations according to the continuum method is given for the case that the specimen contains appreciable concentrations of one or more rather heavy elements. It is shown that use of approximations may lead to unacceptable errors, even in the concentration ranges occurring in biological specimens. As a practical application, the concentration of bromine in the chloroplasts of the red alga Chondrus crispus was determined quantitatively. The inner cells contained more bromine than the epidermal cells: in the chloroplasts of the inner cells bromine concentrations of about 6% could be demonstrated.  相似文献   

16.
The cyclopropene fatty acids that occur in lipids of the cotton plant and other species of the order Malvales are responsible for a number of adverse biological effects subsequent to dietary consumption. Analyzing for these compounds in plant materials is complicated by their instability and lack of specific chemical reactivity. Raman spectroscopy, which takes advantage of an isolated strong band at 1870 cm?1 associated with the cyclopropene double bond, provides a direct method for determination of these cyclopropenoids as components of lipid mixtures at levels down to 0.03%. No derivatization or chemical treatment is required and sample preparation is uncomplicated.  相似文献   

17.
Under various conditions poly(A) exists in different forms such as single-stranded helix, two double-helical forms and others. The formation of double-stranded helices is induced by adenine protonation. Under physiological ionic strengths they are formed at acidic pH, but under the same conditions methylated poly(A) has double-stranded structure at alkaline pH. Since the shift of adenine protonation pKa to alkaline region may be caused not only by chemical modification of poly(A) but also its interaction with proteins, it is quite probable that double oligo(A)-helices are formed in the living cell as well. In this article the hypothesis on possible biological role of poly(A) double-stranded forms has been discussed in details. The models of involvement of double oligo(A)-sequences of RNA in such intracellular processes as termination of mRNA poly(A) tails synthesis and autoregulation of poly(A)-binding protein synthesis are suggested as an example.  相似文献   

18.
A novel, simple, sensitive and selective solid‐phase extraction (SPE)–spectrofluorimetric method has been developed for the determination of atenolol (ATE) in human urine. Because an extraction procedure is required to isolate ATE or eliminate the interfering molecules present in complex human urine for the direct spectrofluorimetric determination, a pH‐sensitive poly(acrylic acid‐ethylene glycol dimethacrylate) [poly(AA‐EGDMA)] hydrogel was developed and used as a SPE adsorbent. Some factors affecting the ATE extraction efficiency, such as washing solvent type and volume, and the volume of elution solvent were optimized. Eluates from SPE cartridges were analyzed using a spectrofluorimeter (λex = 277 nm and λem = 300 nm). The calibration graph was linear over the concentration range 0.15–4.0 µg/mL. Limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.03 and 0.10 µg/mL, respectively. Relatively high intraday [2.06%, mean relative standard deviation (RSD)] and interday (2.6%, mean RSD) precisions were achieved. High mean recovery (95.4%) and low RSD values (3.8%) were obtained for spiked ATE in human urine. The spectrofluorimetric method presented here can be easily applied to assay trace amounts of ATE in pharmaceuticals and biological samples. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

19.
Polarized light that is reflected or transmitted through chiral specimens can be used to detect and identify biological and chemical materials including human tissue. The determination of the silent footprints of the chiral properties of the biological materials on scattered polarized light is the basis for these investigations. It is of primary importance to identify which combinations of the elements of the Mueller matrix for reflected or for transmitted light can be used to determine the optical activity of the biochemical materials. The optical activity of chiral materials is characterized by optical rotation and circular dichroism. The explicit analytical dependence of these specific elements of the Mueller matrix, upon the angles of incidence and scatter, upon the wavelength and upon the type of chirality has the potential to provide experimentalists with guidance in determining the optimum use of optical polarimetric scatterometers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

20.
Infected-cell protein 4 (ICP4), the major regulatory protein in herpes simplex viruses 1 and 2, was previously reported to accept 32P from [32P]NAD in isolated nuclei. This modification was attributed to poly(ADP-ribosyl)ation (C. M. Preston and E. L. Notarianni, Virology 131:492-501, 1983). We determined that an antibody specific for poly(ADP-ribose) reacts with ICP4 extracted from infected cells, electrophoretically separated in denaturing gels, and electrically transferred to nitrocellulose. Our results indicate that all forms of ICP4 observed in one-dimensional gel electrophoresis are poly(ADP-ribosyl)ated. Poly(ADP-ribose) on ICP4 extracted from infected cells was resistant to cleavage by purified poly(ADP-ribose) glycohydrolase unless ICP4 was in a denatured state. Poly(ADP-ribose) added to ICP4 in isolated nuclei was sensitive to this enzyme. This result indicates that the two processes are distinct and may involve different sites on the ICP4 molecule.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号