Zn In Biological Samples Research Articles

INAA method optimization using a 2 k factorial design

In this work a 23 factorial design was carried out aiming the multivariate optimization of Instrumental Neutron Activation Analysis (INAA) for mass fraction determination of Co, Cr, Fe, Rb, Sc, Se and Zn in biological samples and Co, Cr, Fe, Sc and Zn in geological samples. The factors investigated in this study were sample decay time, sample distance to detector and sample measurement time. The optimal condition for each method was outlined according to the main effect and interactions results. It was observed that sample decay time is the most important factor for the INAA optimization in the different methods.

Evaluation of Status of Zinc, Copper, and Iron Levels in Biological Samples of Normal and Arthritis Patients in Age Groups 46 - 60 and 61 - 75 years

A great number of studies have investigated the possible role of trace elements in the etiology and pathogenesis of rheumatoid arthritis (RA). The aim of the study was to evaluate copper (Cu), iron (Fe), and zinc (Zn) levels in three biological samples (scalp hair, blood, and urine) in patients with rheumatoid arthritis (RA) in two groups, age ranges 46 - 60 and 61-75 years, of both genders compared to age-matched healthy individuals. A microwave assisted wet acid digestion procedure was developed as a sample pretreatment for the determination of Cu, Fe, and Zn in biological samples. The digests of all biological samples were analysed for Cu, Fe, and Zn by flame atomic absorption spectrometry (FAAS) using an air/acetylene flame. The proposed method was validated by analyzing certified reference samples of hair, blood, and urine. The results indicated significantly lower levels of Fe, Cu, and Zn in the biological samples (blood and scalp hair) of male and female rheumatoid arthritis patients as compared to control subjects of both genders (p < 0.01). These data present guidance to clinicians and other professional investigating deficiency of essential trace metals in biological samples (scalp hair and blood) of RA patients.

Ionic liquid-based magnetic solid phase extraction coupled with inductively coupled plasma-optical emission spectrometry for the determination of Cu, Cd, and Zn in biological samples

Ionic liquids of methyltrioctylammonium chloride modified magnetic nanoparticles were prepared, and a new method of magnetic solid phase extraction combined with inductively coupled plasma-optical emission spectrometry was established for the determination of Cu, Zn, and Cd in human hair and urine samples. The effect of pH on the extraction of Cu, Zn, and Cd was investigated. The results show that the ionic liquid played a key role in the extraction of target analytes. The magnetic nanoparticles served as the carriers of the ionic liquid and the base of the phase separation. Several parameters affecting the extraction and desorption of the target analytes were investigated including the sample volume, extraction time, eluent concentration and volume, desorption time, sedimentation time, amount of the ionic liquid and Fe3O4@Si–OH, and the optimized conditions were established. Under the optimized conditions, the detection limits of Cu, Zn, and Cd were 0.54, 0.56, and 0.33 μg L−1, respectively, and the relative standard deviations (n = 7) were 4.9% (c = 2 μg L−1), 3.7% (c = 2 μg L−1), and 5.1% (c = 1 μg L−1), respectively. To validate the accuracy of the proposed method, it was applied to analyze certified reference materials of GBW07601 human hair and GBW09103 human urine. The determined values agree with the certified values. The developed method was also employed to analyze human hair and urine, and the recoveries for the spiked samples were in the range of 89.1% to 120%. The developed method was simple, highly sensitive, solvent-free, chelate-free, and could be considered as a green analytical technique.

Preconcentration and Determination of Trace Cu, Pb, and Zn in Biological Samples by Combining Carbon Nanofibers (CNFs) as a Solid Phase Extraction Adsorbent with ICP-MS

Preconcentration and Determination of Trace Cu, Pb, and Zn in Biological Samples by Combining Carbon Nanofibers (CNFs) as a Solid Phase Extraction Adsorbent with ICP-MS

Determination of trace elements in biological samples treated with formic acid by inductively coupled plasma mass spectrometry using a microconcentric nebulizer

A simple and fast method for the determination of As, Ba, Cd, Co, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Rb, Se, Sr, Tl, U, V and Zn in biological samples by inductively coupled plasma mass spectrometry (ICP-MS), after sample solubilization with formic acid and introduction by a microconcentric nebulizer, is proposed. The sample is mixed with formic acid, kept at 90 °C for one hour and then diluted with nitric acid aqueous solution to a 50% v/v formic acid and 1% v/v nitric acid final concentrations. The final sample solution flow rate for introduction into the plasma was 30 μL min −1. The optimized and adopted nebulizer gas flow rate was 0.7 L min −1 and RF power was 800 W. These conditions are very different than those normally used when a conventional nebulizer is employed. Rodhium was used as internal standard. External calibration against aqueous standard solutions, without formic acid, could be used for quantification, except for As, Se and Zn. However, external calibration with 50% formic acid allows the determination of all analytes with high accuracy and it is recommended. The detection limits were between 0.0005 (Tl) and 0.22 mg kg −1 (Fe) and the precision expressed by the relative standard deviations (RSD) were between 0.2% (Sr) and 3.5% (Ga). Accuracy was validated by the analysis of four certified reference biological materials of animal tissues, comparing the results by linear regressions and by the t-test at a 95% confidence level. The recommended procedure avoids plasma instability and carbon deposit on the cones.

Evaluation of Essential Trace and Toxic Elements in Biological Samples of Normal and Night Blindness Children of Age Groups 3–7 and 8–12 Years

The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization estimates 13.8 million children to have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial, and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological samples composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of Zn, Mg, Ca, K, Na, As, Cd, and Pb in scalp hair, blood, and urine of night blindness children age ranged 3-7 and 8-12 years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment, for the determination of As, Ca, Cd, K, Pb, Mg, Na, and Zn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The results of this study showed that the mean values of As, Cd, Na, and Pb were significantly higher in scalp hair, blood, and urine samples of male and female night blindness children than in referents (p < 0.001), whereas the concentrations of Zn, Ca, K, and Mg were lower in the scalp hair and blood but higher in the urine samples of night blindness children. These data present guidance to clinicians and other professional investigating deficiency of essential mineral elements in biological samples (scalp hair and blood) of night blindness children.

Status of essential trace metals in biological samples of diabetic mother and their neonates

There is accumulating facts that the metabolism of essential trace elements is altered in diabetic patients. The aim of present study was to compare the status of essential trace elements, chromium (Cr), manganese (Mn), and zinc (Zn) in biological samples (whole blood, urine and scalp hair) of insulin dependent diabetic mothers (age ranged 30-40) and their newly born infants (n = 76). An age matched 68 non-diabetic mothers and their infants, residing in the same locality, were selected as referents. For a comparative study, the biological samples of non-diabetic and diabetic pregnant and non pregnant of same age group and socio-economics status were also analysed. The biological samples (scalp hair, blood and urine) were collected from study and referent groups. The Cr, Mn and Zn concentrations in all three biological samples were determined by a flame/electrothermal atomic absorption spectrometer, prior to microwave assisted acid digestion. The validity and accuracy of the methodology was checked by certified reference materials (CRMs) and using conventional wet acid digestion method on same CRMs. The mean values of Cr, Mn and Zn in scalp hair and blood samples of diabetic mothers and their infants were significantly lower as compared to the referent mothers-infants pairs (p < 0.01), while urinary excretion of all these elements were high in diabetic mother-infant pair samples. The deficiencies of essential trace elements, Cr, Mn and Zn in biological samples of diabetic women, may play role in the pathogenesis of diabetes mellitus and impacts on their neonates.

Electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry for the determination of Fe, Co, Ni, Cu, and Zn in biological samples

Slurry sampling electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry (ETV-DRC-ICP-MS) has been applied to determine Fe, Co, Ni, Cu, and Zn in biological samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Pd was used as the modifier. The effectiveness of the ETV sample introduction technique and dynamic reaction cell in alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied to determine Fe, Co, Ni, Cu, and Zn in NIST SRM 1573a tomato leaves reference material and NRCC DORM-2 dogfish muscle reference material and also real samples such as a tea and a swordfish sample purchased locally. Since the sensitivities of the elements studied in slurry and aqueous solution were different, an analyte addition technique was used for the determinations. The analytical results of the reference materials agreed with the certified values. The precision between sample replicates was better than 6% for all determinations. The method detection limit estimated from analyte addition curves was 0.01, 0.006, 0.007, 0.004, and 0.006 microg g(-1) for Fe, Co, Ni, Cu, and Zn, respectively, in the original biological samples.

Statistical Evaluation of Cu, Mn and Zn Determinations in Biological Samples by Radiofrequency Capacitively Coupled Plasma Atomic Emission Spectrometry Using the Bland and Altman Test

This paper presents a statistical comparison of Cu, Mn and Zn determinations in biological samples by low power radiofrequency capacitively coupled Ar plasma (275 W; 27.12 MHz; 0.4 L min−1 flow rate) atomic emission spectrometry and flame atomic absorption spectrometry using statistical analysis according to the Bland and Altman test and linear regression. For a content (µg g−1 dry mass) of 5-43 Cu, 10-15800 Mn and 8-1100 Zn in fish fillet and freshwater molluscs, there was no significant bias in r.f.CCP-AES for a 95% confidence level. Certified reference materials were analysed by r.f.CCP-AES, and a good agreement between analysis results and certified values was obtained. Matrix effects of Ca and Na and their influence on the detection limits of Cu, Mn and Zn are presented for both methods. As compared to FAAS, r.f.CCP-AES is more prone to interferences and, consequently, the detection limits for Cu, Mn and Zn in biological samples (2; 2 and 3 µg g−1 dry mass) are higher than those in FAAS. In spite of these problems, r.f.CCP-AES is capable of accurate and precise analyses of biological samples.

Determination of As, Cd, Hg, Cu and Zn in biological samples by radiochemical neutron activation analysis

In this work, a simple group separation scheme based on extraction for NAA determination of trace of As, Cd, Hg, Cu and Zn in biological materials is described. For this purpose, zinc-diethyldithiocarbamate, Zn(DDC)2, and methyl isobutyl ketone-iodide have been chosen as reagents. The elements can be extracted successively and quantitatively from strong mineral acids without adjusting pH of the solution, and separated into two groups suitable for gamma-ray spectrometry. Samples of 100–200 mg dry weight were double-sealed into polyethylene bags and irradiated in a swimming pool reactor with a thermal neutron flux of 1013n·cm−2·s−1 for 44 hours. After a cooling period of 1–3 days, the samples were digested with microgram quantities of carrier in concentrated nitric acid and sulfuric acid at 150°C for 3.5 hours in a teflon bomb, then extracted as described above. The reliability of the analytical method was checked using reference materials Horse Kidney IAEA H-8, Human Hair NIES-5 and Tomato Leaves NBS-1573. Most of the results obtained for reference materials agreed with the certified values12. Chinese autopsy samples of hair and liver were presented.

Determination of Fe and Zn in biological samples by radiochemical neutron activation analysis

Radiochemical NAA methods have been developed for the simultaneous determination of Fe and Zn in biological samples. The method involves reactor irradiation, dissolution in 3M HCl and solvent extraction followed by counting on a scintillation gamma-ray spectrometer. Iron was separated with aqueous cupferron and extracted into chloroform while Zn was extracted with 2-thenoyl trifluoroacetone (TTA) into methyl isobutyl ketone (MIBK). Reaction conditions such as pH and the effect of solvents and various ions were studied using tracer activities. The methods have been employed for trace level determination of Fe and Zn in NBS, SRMs, Bowen's Kale, IAEA CRMs and other plant leaves.