Simultaneous determination of fluorine and iodine in urine by ion chromatography with electrochemical pretreatment

A new method for the simultaneous determination of fluorine and iodine in urine by ion chromatography(IC) with electrochemical pretreatment has been developed.The pretreatment was performed in a novel electrochemical oxidation-neutralization device(EOND),in which iodide of the sample was oxidized to iodate and the alkaline digestion sample solution was neutralized.Under the optimized conditions,the limits of detection(LOD,S/N = 3) were 2.5μg/L for fluoride and 20μg/L for iodate,respectively.The recoverie...     

On chromium direct ETAAS determination in serum and urine

A simple, accurate and reliable method for direct electrothermal atomic absorption spectrometric (ETAAS) determination of chromium in serum and urine samples without any preliminary sample pretreatment is described. Instrumental parameters are optimized in order to define: the most suitable atomizer, optimal temperature program and efficient modifier. An appropriate quantification method is proposed taking into account a matrix interference study. Pyrocoated graphite tubes and wall atomization, pretreatment temperature of 700 °C, atomization temperature of 2600 °C, hydrogen peroxide as modifier and standard addition calibration are recommended. The accuracy of the method proposed for Cr determination in serum and urine was confirmed by comparative analysis of parallel samples after wet or dry ashing as well as by the analysis of two certified reference materials: Serum, Clin Rep 1 and Lypochek Urine, level 1. The detection and determination limits achieved for both matrices are 0.08 μg/L and 0.15 μg/L respectively. The relative standard deviation varied between 15 and 18 % for the chromium content in the samples in the range 0.08–0.2 μg/L and between 4 and 7 % for the chromium content in the range 0.2–2.0 μg/L for both matrices.      

Kinetic spectrophotometric determination of bromide in clidinium-c drug

A simple,rapid and sensitive method has been described for the determination of the trace amounts of bromide.The method is based on the catalytic effect of bromide ion on the oxidation of methylene blue by bromate in sulfuric acid media.The reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of methylene blue at 665 nm. Bromide was determined in the range of 0.05-1.90μg/mL with the detection limit of 0.03μg/mL.The relative standard deviations of five replicate determinations of 0.20 and 10.0μg/mL of bromide were 2.4%and 1.8%,respectively.The influence of potential interfering ions and substances was studied.The method is applied to the analysis of bromide in clidinium-c tablet as a real sample.     

A new kinetic spectrophotometric method for the determination of major metabolite of heroin in biological samples

This study describes a simple,rapid and selective catalytic kinetic spectrophotometric method for the determination of 6- monoacetylmorphine（6-MAM） as major metabolite of heroin in biological samples.The method is based upon the catalytic effect of 6-MAM on the oxidation of Janus Green by bromate in acid media.The reaction was followed spectrophotometrically by measuring the decrease in absorbance of Janus Green at 618 nm.The dependence of sensitivity on the reaction variables was studied.Under optimum conditions,two linear calibration curves over the range 0.1-1.0μg mL^-1 and 1.0-34.0μg mL^-1 of 6- MAM were obtained.The detection limit was 1.2×10²μg mL^-1 of 6-MAM.The relative standard deviations for six replicate determinations of 0.8 and 5.0μg mL^-1 of 6-MAM were 1.4 and 1.1%respectively.The effect of various species commonly associated with heroin in real samples was also investigated.The proposed method was successfully applied in human urine and serum samples with satisfactory results.     

Selective Determination of Nanogram γ-Globulin in Human Blood Serum by Resonance Light Scattering of Functionalized Nano-PbS

Functionalized nano-PbS has been prepared and characterized. The functionalized nanoparticles have good dispersibility in water. Reaction of functionalized nano-PbS with γ-globulin (γ-IgG) results an enhanced resonance light scattering (RLS) around 385nm.However, when the content of HSA is lower than 0.5μg/ml^-1 the RLS enhancement is very weak and is nonlinear to concentration of HSA. Based on these results, a new direct quantitative determination method for γ-globulin in blood serum samples without separation is established.Under optimal conditions, the enhanced RLS intensity is in proportion to the γ-IgG concentration in the range 10-500ng/mL. The limit of detection is 2.75ng/mL. This method is proved to be very sensitive, rapid, simple and selective for detection of γ-IgG in blood serum.     

Determination of catecholamines by ion chromatography coupled to acidic potassium permanganate chemiluminescence detection

A simple,fast,sensitive,highly selective and eco-friendly analytical method for the determination of catecholamines in human urine by ion chromatography（IC） with chemiluminescence（CL） detection was described in this paper.Using 12 mmol/L H₂SO₄ without any organic additive as eluent,three catecholamines including epinephrine（EP）,norepinephrine（NE） and dopamine（DA） were well separated on a cation-exchange column.The CL detection was based on the reaction of analytes with acidic potassium permanganate in the presence of formaldehyde as an enhancer.The absence of methanol and acetonitrile in eluent made the proposed method more sensitive and eco-friendly.Under the optimal conditions,the linear range of the proposed method was in the range of 0.02-0.5μg/mL.The limit of detection（LOD） was in the range of 0.6 and 5.1μg/L.The relative standard deviations （RSD） for 0.1μg/mL mixed standard solution were in the range of 0.8-1.9%（n = 11）.The method has been applied to the determination of catecholamines in human urine successfully.Excellent spiked recoveries were achieved for catecholamines ranged from 91.2%to 112.7%.     

超高效液相色谱-串联质谱法测定牛尿液中的甲状腺抑制剂(英文)

Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.     

Capillary electrophoresis with direct chemiluminescence detection for the analysis of catecholamines in human urine

A rapid and sensitive method for the analysis of three catecholamines by capillary electrophoresis(CE)with directchemiluminescence(CL)detection is described.The detection limits(S/N=3)were 1.3*10-8g/mL for isoprenaline,1.0*10-8g/mL for epinephrine and 2.8*10-8g/mL for dopamine.The proposed method was successfully applied to theanalysis of catecholamines in urine samples of cigarette smokers and nonsmokers.The results showed that there is a close relationbetween the release of dopamine in human body fluids and cigarette smoking/nonsmoking.     

Determination of Proteins by Measuring Total Internal-reflected Resonance Light Scattering Signals on Water／Tetrachloromethane Interface with Evans Blue and Cetyltrimethylammonium Bromide

A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane( H2O/CCl4 ) interface. In an aqueous medium with pH value in the range of 3. 29-3. 78, electrostatic attraction occurs between the negatively charged Evans Blue(EB) and positively charged proteins, forming hydrophobic ion associates and resulting in EB-protein adsorption on H20/CC14 interface. The presence of cetyhrimethylammonium bromide prompts this adsorption, resulting in strongly enhanced TIR-RLS signals. The intensity of the enhanced TIR-RLS at 360-370 nm was found to be proportional to the concentration of proteins. For bovine serum albumin and human serum albumin, the linear range of detection is 0. 07-1.2μLg/mL and the limits of detection are 6. 68 and 6. 30 ng/mL(3σ) , respectively, while for lysozyme, the linear range of detection is 0. 06-1.0μg/mL and the limit of detection is 6. 0 ng/mL(3σ). The content of the total albumin in a human urine samplc could be directly determiined by using the standard addition method with a percent recovery of 97.6%-104. 1% , and the RSD ranging from 1. 9% to 4. 2%.     

Combination of hollow fiber-based liquid-phase microextraction with sweeping techniques in micellar electrokinetic chromatography for the determination of Strychnos alkaloids in human urine

A new method for the enrichment of Strychnos alkaloids in biological samples via liquid-phase microextraction (LPME) based on porous polypropylene hollow fibers in combination with on-line sweeping in micellar electrokinetic chromatography was developed. The calibration curve was linear over the range of 20-200 ng mL-1 for both strychnine and brucine in human urine sample. The detection limits (S/N=3:1) for strychnine and brucine were 1 ng mL-1 and 2 ng mL-1, respectively. The LPME-sweeping method has been successfully applied to the analysis of strychnine and brucine in real urine samples.     

气相色谱-原子吸收联用技术测定人体体液中烷基汞

建立了一种用于生物样品中分子形态分析的气相色谱与原子吸收联用系统。系统的转移线为聚四氟乙烯管,组分在色谱住内分离后,经转移线运送到原子吸收检测系统。实验证明:系统具有灵敏度高、选择性好的优点,例汞绝对检测限为10-2ng,并首次用于人体血液和尿液中烷基隶的两种形态即氯化甲基汞和二甲基汞的定性和定量分析。     

Molecules and their functions in autophagy

Autophagy is a self-degradation system of cellular components through an autophagosomal-lysosomal pathway. Over the last 15 yr, yeast genetic screens led to the identification of a number of genes involved in the autophagic pathway. Most of these autophagy genes are present in higher eukaryotes and regulate autophagy process for cell survival and homeostasis. Significant progress has recently been made to better understand the molecular mechanisms of the autophagy machinery. Especially, autophagy process, including the regulation of autophagy induction through mTOR and the nucleation and elongation in autophagosome formation through class III phosphatidylinositol 3-kinase complex and ubiquitin-like conjugation systems, became evident. While many unanswered questions remain to be answered, here, we summarize the recent process of autophagy with emphasis on molecules and their protein complexes along with advanced molecular mechanisms that regulate the autophagy machinery.     

Thermogravimetric analysis of human renal calculi sampled in nineteenth century patients

TG and DTG curves of human renal calculi of patients living in the nineteenth century in the South of Italy are reported and compared with those of presentday patients. Marked differences in calculi composition are found in the two different historical periods, that are hypothetically discussed in terms of different diets and of alimentary customs of countries of the considered patients.Work supported by Consiglio Nazionale delle Ricerche (CNR) of Italy.     

等速电泳分析人血红蛋白

应用等速电泳（ＩＴＰ）分析了２０例健康者、１０例糖尿病患者及３例异常血红蛋白病患者的血红蛋白组分。健康者血红蛋白的ＩＴＰ分析图可分为５个部分,即ＨｂＡ_（１ａ）,ＨｂＡ_（１ｂ）＋ＨｂＡ_（１ｃ）＋ＨｂＦ,ＨｂＡ_０,ＨｂＡ_２和ＨｂＵ,并计算出各组分的均值±标准差和各组分的相对值。病理组的ＩＴＰ分析图和各组分的测定值均与健康者明显不同。     

氟元素与人体健康

氟元素是人体必需微量元素，在人体内主要分布于骨骼和牙齿中。氟通过各种途径对人体发生作用。人体内少量的氟对于生长发育，骨骼代谢等有一定的影响，而含氟量过量或过少会引起某些疾病，并且氟的特性对于人体健康也有影响。     

MALDI／MS法应用于血液制品的定性质量评价

本文简述了运用基体辅助激光解吸电离质谱进行血液制品定性质量评价的方法，用此法能检出其他方法不能检出的痕量杂质蛋白。     

Synergistic Action of Membrane-Bound and Water-Soluble Antioxidants in Neuroprotection

Prevention of neurodegeneration during aging, and support of optimal brain function throughout the lifespan, requires protection of membrane structure and function. We review the synergistic action of different classes of dietary micronutrients, as well as further synergistic contributions from exercise and stress reduction, in supporting membrane structure and function. We address membrane-associated inflammation involving reactive oxygen species (ROS) that produce immune regulators from polyunsaturated fatty acids (PUFAs) of membrane phospholipids. The potential of dietary micronutrients to maintain membrane fluidity and prevent chronic inflammation is examined with a focus on synergistically acting membrane-soluble components (zeaxanthin, lutein, vitamin E, and omega-3 PUFAs) and water-soluble components (vitamin C and various phenolics). These different classes of micronutrients apparently operate in a series of intertwined oxidation-reduction cycles to protect membrane function and prevent chronic inflammation. At this time, it appears that combinations of a balanced diet with regular moderate exercise and stress-reduction practices are particularly beneficial. Effective whole-food-based diets include the Mediterranean and the MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay diet, where DASH stands for Dietary Approaches to Stop Hypertension).     

Mineralogical and Geochemical Characteristics of the Human Body Ash Residue

The article is devoted to the element composition of the human body ash residue of some Russian cities. It presents the element composition of the human body ash residue, the distribution of elements in the ash residue depending on age and sex. The specific elements of different cities, showing the possible influence of the environmental conditions on the element composition of the human body ash residue. The main objective of this paper is to study the element composition of the human body ash residue and determine the regional characteristics. The methods of instrumental neutron activation analysis and inductively coupled plasma mass spectrometry were applied, an electronic microscope being used as a tool. The result of the research is 63 elements identified within in the human body ash residue. The issue is topical as it expands the knowledge of rare and radioactive elements within the human body and contributes to medicine, for example, by identifying the chemical elements to be included in a person's diet.     

镁与人体健康

论述了镁在人体中的作用和缺乏症状，研究了人体补充镁的途径，以及医用镁化合物在人体健康中的应用。