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1.
S. N. Husaini J. H. Zaidi Matiullah M. Arif M. Akram 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(2):459-468
The indiscriminate discharge of untreated industrial effluents and solid wastes into the open environment poses a serious
threat to the ecosystem. Gujranwala is an industrial city of Pakistan wherein a large number of different industries are situated
and majority of them are not equipped with proper recycling or effluent treatment plants. Unfortunately, untreated industrial
effluents are locally used for the irrigation purposes which may result in higher concentrations of toxic metals in the crops
and vegetables. Therefore, prime objective of the present study was to determine concentrations of toxic metals in the polluted
soils, vegetables and crops grown in the vicinity of industrial areas using neutron activation analysis technique. The results
obtained showed higher values of toxic metals in the studied samples. The observed highest concentration of As (0.94 ± 0.06)
in spinach, Br (69 ± 9) in turnip, Co (0.83 ± 0.01) in millet, Cr (51.7 ± 4.2) in wheat, Mn (76.2 ± 7.3) in tomato, Sb (0.5 ± 0.06)
in rice, Cl (31698 ± 3921) and Se (3.4 ± 0.4) in carrot. These values are higher than those reported in the literature. 相似文献
2.
S. N. Husaini J. H. Zaidi Matiullah M. Arif 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(3):655-665
Pakistan is an agricultural country, yet it is facing a serious threat due to the shortage of water resources and degradation
of the agricultural land by the pollution of industrial effluents. A limited number of the current industries are equipped
with proper operating treatment plants. Generally, the untreated effluents are disposed off to the open environment which
is used for irrigation purposes. Therefore, vegetables and crops grown around the industrial areas is a major potential source
of metal poisoning which pose a serious risk to the general public. Hence, study of the toxicity level in vegetables and crops
is highly desirable. In this regard, systematic studies have been carried out to determine concentration levels of toxic elements
in the samples of vegetables, crops, effluents and soil collected from the industrial areas of the Faisalabad. After processing,
these samples were analyzed using neutron activation analysis and atomic absorption spectrometric techniques. The highest
concentrations of toxic metals were observed for As (2.73 ± 0.34) in cabbage, Cd (1.5 ± 0.1), Ni (5.1 ± 0.9) and Pb (4.3 ± 0.2)
in corn, Co (0.65 ± 0.02), and Sb (0.09 ± 0.01) in carrot, Cr (9.63 ± 1.3), Mn (46.5 ± 4.2) and Se (1.03 ± 0.1) in millet,
Cu (11.3 ± 1.1) in tomato vegetables and crop samples. Although, the observed toxicity levels in vegetables and crop samples
were higher than those grown in non-industrial areas, yet these toxicity levels are within the safe recommended limits. 相似文献
3.
S. N. Husaini J. H. Zaidi Matiullah M. Akram 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(1):203-211
The industrial pollution is exponentially growing in the developing countries due to the discharge of untreated effluents
from the industries in the open atmosphere. This may cause severe health hazards in the general public. To reduce this effect,
it is essential to remove the toxic and heavy metals from the effluents before their disposal into the biosphere. In this
context, samples of the effluents were collected from the textile/yarn, ceramics and pulp/paper industries and the concentrations
of the toxic metal ions were determined using neutron activation analysis (NAA) technique. The observed concentration values
of the As, Cr and Fe ions, in the unprocessed industrial effluents, were 4.91 ± 0.8, 9.67 ± 0.7 and 9.71 ± 0.8 mg/L, respectively
which was well above the standard recommended limits (i.e. 1.0, 1.0 and 2.0 mg/L, respectively). In order to remove the toxic metal ions from the effluents, the samples were treated with pea nut husk fence.
After this treatment, 91.5% arsenic, 81.9% chromium and 66.5% iron metal ions were successfully removed from the effluents.
Then the treated effluents contained concerned toxic metal ions concentrations within the permissible limits as recommended
by the national environmental quality standards (NEQS). 相似文献
4.
S. N. Husaini J. H. Zaidi Matiullah M. Akram 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(3):903-910
Due to the significance of industrial waste water pollution, which creates severe health hazards in humans, this study concentrates over the reduction and determination of the amounts of toxic metals/pollution parameters in the effluents leached from different processes of the textile industry. The concentrations of metal ions were measured by using neutron activation analysis (NAA) technique. The values of toxic metals such as As (49.1 ± 1.8 mg/L), Cu (42.7 ± 1.5 mg/L), Ni (41.1 ± 3.3 mg/L), Mn (51.1 ± 0.7 mg/L), Sb (1.89 ± 0.04 mg/L), Se (0.41 ± 0.01 mg/L), Co (7.5 ± 0.3 mg/L), Cr (8.5 ± 0.5 mg/L) and Cd (1.21 ± 0.08 mg/L) were found very high in crude textile??s effluents as compared to their standard recommended limits. The immense variation observed among the injurious pollutants of the effluents i.e. pH, temperature, electrical conductivity, turbidity, biological oxygen demands, chemical oxygen demands, total suspended solids, total dissolved solids, total solids etc. The toxic metals and injurious pollutants in the unprocessed effluents have been reduced in the post filtration effluents up to 98% and 96% respectively with the help of an ultra-filtration membrane therapy unit. 相似文献
5.
Minakata K Nozawa H Gonmori K Yamagishi I Suzuki M Hasegawa K Watanabe K Suzuki O 《Analytical and bioanalytical chemistry》2011,400(7):1945-1951
An electrospray ionization tandem mass spectrometric (ESI-MS-MS) method has been developed for the determination of cyanide
(CN–) in blood. Five microliters of blood was hemolyzed with 50 μL of water, then 5 μL of 1 M tetramethylammonium hydroxide solution
was added to raise the pH of the hemolysate and to liberate CN– from methemoglobin. CN– was then reacted with NaAuCl4 to produce dicyanogold, Au(CN)2–, that was extracted with 75 μL of methyl isobutyl ketone. Ten microliters of the extract was injected directly into an ESI-MS-MS
instrument and quantification of CN– was performed by selected reaction monitoring of the product ion CN– at m/z 26, derived from the precursor ion Au(CN)2– at m/z 249. CN– could be measured in the quantification range of 2.60 to 260 μg/L with the limit of detection at 0.56 μg/L in blood. This
method was applied to the analysis of clinical samples and the concentrations of CN– in the blood were as follows: 7.13 ± 2.41 μg/L for six healthy non-smokers, 3.08 ± 1.12 μg/L for six CO gas victims, 730 ± 867 μg
for 21 house fire victims, and 3,030 ± 97 μg/L for a victim who ingested NaCN. The increase of CN– in the blood of a victim who ingested NaN3 was confirmed using MS-MS for the first time, and the concentrations of CN– in the blood, gastric content and urine were 78.5 ± 5.5, 11.8 ± 0.5, and 11.4 ± 0.8 μg/L, respectively. 相似文献
6.
J. Feldmann Katie John Paramee Pengprecha 《Analytical and bioanalytical chemistry》2000,368(1):116-121
Cation exchange and anion exchange liquid chromatography were coupled to an ICP-MS and optimised for the separation of 13
different arsenic species in body fluids (arsenite, arsenate, dimethylarsinic acid (DMAA), monomethylarsonic acid (MMAA),
trimethylarsine oxide (TMAO), tetramethylarsonium ion (TMA), arsenobetaine (AsB), arsenocholine (AsC), dimethylarsinoyl ethanol
(DMAE) and four common dimethylarsinoylribosides (arsenosugars). The arsenic species were determined in seaweed extracts and
in the urine and blood serum of seaweed-eating sheep from Northern Scotland. The sheep eat 2–4 kg of seaweed daily which is
washed ashore on the most northern Island of Orkney. The urine, blood and wool of 20 North Ronaldsay sheep and kidney, liver
and muscle from 11 sheep were sampled and analysed for their arsenic species. In addition five Dorset Finn sheep, which lived
entirely on grass, were used as a control group. The sheep have a body burden of approximately 45–90 mg arsenic daily. Since
the metabolism of arsenic species varies with the arsenite and arsenate being the most toxic, and organoarsenic compounds
such as arsenobetaine the least toxic compounds, the determination of the arsenic species in the diet and their body fluids
are important. The major arsenic species in their diet are arsenoribosides. The major metabolite excreted into urine and blood
is DMAA (95 ± 4.1%) with minor amounts of MMAA, riboside X, TMA and an unidentified species. The occurrence of MMAA is assumed
to be a precursor of the exposure to inorganic arsenic, since demethylation of dimethylated or trimethylated organoarsenic
compounds is not known (max. MMAA concentration 259 μg/L). The concentrations in the urine (3179 ± 2667 μg/L) and blood (44
± 19 μg/kg) are at least two orders of magnitude higher than the level of arsenic in the urine of the control sheep or literature
levels of blood for the unexposed sheep. The tissue samples (liver: 292 ± 99 μg/kg, kidney: 565 ± 193 μg/kg, muscle: 680 ±
224 μg/kg) and wool samples (10 470 ± 5690 μg/kg) show elevated levels which are also 100 times higher than the levels for
the unexposed sheep.
Received: 29 February 2000 / Revised: 26 April 2000 / Accepted: 1 May 2000 相似文献
7.
The new analytical method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination
of diacylhydrazine insecticide residues in fruits and vegetables was developed using ultra-performance liquid chromatography
coupled with tandem mass spectrometry (UPLC-MS/MS). The four insecticides (tebufenozide, methoxfenozide, chromafenozide, and
halofenozide) were extracted from six fruit and vegetable matrices using acetonitrile and subsequently cleaned up using primary
secondary amine (PSA) or octadecylsilane (C18) as sorbent prior to UPLC-MS/MS analysis. The determination of the target compounds
was achieved in less than 3.0 min using an electrospray ionization source in positive mode (ESI+) for tebufenozide, methoxfenozide,
and halofenozide and in negative mode (ESI−) for chromafenozide. The limits of detection were below 0.6 μg kg−1, while the limit of quantification did not exceed 2 μg kg−1 in different matrices. The QuEChERS procedure by using two sorbents (PSA and C18) and the matrix-matched standards gave satisfactory
recoveries and relative standard deviation (RSD) values in different matrices at four spiked levels (0.01, 0.05, 0.1, and
1 mg kg−1). The overall average recoveries for this method in apple, grape, cucumber, tomato, cabbage, and spinach at four levels ranged
from 74.2% to 112.5% with RSDs in the range of 1.4–13.8% (n = 5) for all analytes. This study provides a theoretical basis for China to draw up maximum residue limits and analytical
method for diacylhydrazine insecticide in vegetables and fruits. 相似文献
8.
Juan Agüero José-Esteban Peris Eduardo San-Martín 《Fresenius' Journal of Analytical Chemistry》1999,363(3):289-293
An analytical method for detecting and quantifying cefotaxime in plasma and several tissues is described. The method was
developed and validated using plasma and tissues of rats. The samples were analyzed by reversed phase liquid chromatography
(HPLC) with UV detection (254 nm). Calibration graphs showed a linear correlation (r > 0.999) over the concentration ranges
of 0.5–200 μg/mL and 1.25–25 μg/g for plasma and tissues, respectively. The recovery of cefotaxime from plasma standards prepared
at the concentrations of 25 μg/mL and 100 μg/mL was 98.5 ± 3.5% and 101.8 ± 2.2%, respectively. The recovery of cefotaxime
from tissue standards of liver, fat and muscle, prepared at the concentration of 10 μg/g was: 89.8 ± 1.2% (liver), 103.9 ±
6.5% (fat) and 97.8 ± 2.1% (muscle). The detection (LOD) and quantitation (LOQ) limits for plasma samples were established
at 0.11 μg/mL and 0.49 μg/mL, respectively. The values of these limits for tissues samples were approximately 2.5 times higher:
0.3 μg/g (LOD) and 1.25 μg/g (LOQ). For plasma samples, the deviation of the observed concentration from the nominal concentration
was less than 5% and the coefficient of variation for within-day and between-day assays was less than 6% and 12%, respectively.
The method was used in a pharmacokinetic study of cefotaxime in the rat and the mean values of the pharmacokinetic parameters
are given.
Received: 25 May 1998 / Revised: 27 July 1998 / Accepted: 1 August 1998 相似文献
9.
Beltrami D Calestani D Maffini M Suman M Melegari B Zappettini A Zanotti L Casellato U Careri M Mangia A 《Analytical and bioanalytical chemistry》2011,401(4):1401-1409
An integrated approach based on the use of inductively coupled plasma mass spectrometry (ICP-MS) and scanning electron microscopy
(SEM) for the qualitative and quantitative analyses of metal particles in foods was devised and validated. Different raw materials
and food products, like wheat, durum wheat, wheat flour, semolina, cookies, and pasta were considered. Attention was paid
to the development of sample treatment protocols for each type of sample to avoid potential artifacts such as aggregation
or agglomeration. The analytical protocols developed followed by ICP-MS and SEM investigations allowed us the quantitative
determination and the morphological and dimensional characterization of metal nano- and microparticles isolated from the raw
materials and finished food products considered. The ICP-MS method was validated in terms of linearity (0.8–80 μg/g and 0.09–9 μg/g
for Fe and Ti, respectively), quantification limits (0.73 μg/g for Fe and 0.09 μg/g for Ti), repeatability (relative standard
deviation (RSD) % equal to 10% for Fe and 20% in a wheat matrix as an example), and extraction recoveries (93 ± 2–101 ± 2%).
Validation of the scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDS) measurements was performed working
in a dimensional range from 1 to 100 μm with an estimated error in the size determination equal to 0.5 μm. ICP-MS data as
well as SEM measurements showed a decrease in the concentration of metal particles from wheat to flour and from durum wheat
to semolina samples, thus indicating an external contamination of grains by metal particles. These findings were confirmed
by environmental SEM analysis, which allowed investigation of particles of lower dimensions. Generally, the largest number
of particles was found in the case of iron and titanium, whereas particles of copper and zinc were only occasionally found
without any possibility of quantifying their number. 相似文献
10.
Spínola V Mendes B Câmara JS Castilho PC 《Analytical and bioanalytical chemistry》2012,403(4):1049-1058
This study provides a versatile validated method to determine the total vitamin C content, as the sum of the contents of L-ascorbic acid (L-AA) and dehydroascorbic acid (DHAA), in several fruits and vegetables and its degradability with storage
time. Seven horticultural crops from two different origins were analyzed using an ultra-high-performance liquid chromatographic–photodiode
array (UHPLC-PDA) system, equipped with a new trifunctional high strength silica (100% silica particle) analytical column
(100 mm × 2.1 mm, 1.7 μm particle size) using 0.1% (v/v) formic acid as mobile phase, in isocratic mode. This new stationary phase, specially designed for polar compounds, overcomes
the problems normally encountered in HPLC and is suitable for the analysis of large batches of samples without L-AA degradation.
In addition, it proves to be an excellent alternative to conventional C18 columns for the determination of L-AA in fruits
and vegetables. The method was fully validated in terms of linearity, detection (LOD) and quantification (LOQ) limits, accuracy,
and inter/intra-day precision. Validation experiments revealed very good recovery rate of 96.6 ± 4.4% for L-AA and 103.1 ± 4.8
% for total vitamin C, good linearity with r
2
-values >0.999 within the established concentration range, excellent repeatability (0.5%), and reproducibility (1.6%) values.
The LOD of the method was 22 ng/mL whereas the LOQ was 67 ng/mL. It was possible to demonstrate that L-AA and DHAA concentrations
in the different horticulture products varied oppositely with time of storage not always affecting the total amount of vitamin
C during shelf-life. Locally produced fruits have higher concentrations of vitamin C, compared with imported ones, but vegetables
showed the opposite trend. Moreover, this UHPLC-PDA methodology proves to be an improved, simple, and fast approach for determining
the total content of vitamin C in various food commodities, with high sensitivity, selectivity, and resolving power within
3 min of run analysis. 相似文献
11.
Byrdwell WC 《Analytical and bioanalytical chemistry》2011,401(10):3317-3334
A method is demonstrated for analysis of vitamin D fortified dietary supplements that eliminates virtually all chemical pretreatment
prior to analysis, which is referred to as a “dilute-and-shoot” method. Three mass spectrometers, in parallel, plus a UV detector,
an evaporative light-scattering detector (ELSD), and a corona charged aerosol detector (CAD) were used to allow a comparison
of six detectors simultaneously. Ultraviolet data were analyzed using internal standard, external standard, and response factor
approaches. The contents of gelcaps that contained 2,000 IU (50 μg) vitamin D3 in rice bran oil, diluted to 100 mL, were analyzed without the need for lengthy saponification and extraction. Vitamin D3 was analyzed using UV detection, extracted ion chromatograms, selected ion monitoring (SIM) atmospheric pressure chemical
ionization mass spectrometry (APCI-MS), and two transitions of multiple reaction monitoring (MRM) APCI-MS. The internal standard,
external standard, and response factor methods gave values of 0.5870 ± 0.0045, 0.5893 ± 0.0041, and 0.5889 ± 0.0045 μg/mL,
respectively, by UV detection. The values obtained by MS were 0.6117 ± 0.0140, 0.6018 ± 0.0244, and 0.5848 ± 0.0146 μg/mL
by SIM and two transitions of MRM, respectively. The triacylglycerols in the oils were analyzed using full-scan APCI-MS, electrospray
ionization (ESI) MS, up to MS4, an ELSD, and a CAD. The method proved to be very sensitive for vitamin D3, as well as triacylglycerols (TAGs), allowing identification of intact TAGs containing fatty acids up to 28 carbons in length.
LC-ESI-MS of glycerin polymers is also demonstrated. 相似文献
12.
L. Sajo-Bohus M. C. Scott E. D. Greaves L. J. Somervaille S. Green T. Avila F. Loaiza L. Foglietta 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(2):251-255
Gamma-ray induced X-ray emission (GIXE) technique for elemental lead in-vivo tibial measurement using a large volume hyper
pure germanium detector is presented with the most convenient source-sample-detector geometry. The system operates advantageously
when several parameters are considered for a lower dead time operation. The detection limit (DL) is better that 3.5 μg/g of
Ca. Results of in-vivo average tibial lead concentration for some of the monitored groups are: control 7 μg of lead per g
of Ca; gasoline filling attendants 6 μg/g of Ca; custom office workers near the DL; industrial workers range from DL up to
84±3 μg/g of Ca, suggesting that lead accumulation in the bone does not represent a major health risk
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
Evaluation of a novel ELISA for serotonin: urinary serotonin as a potential biomarker for depression
Nichkova MI Huisman H Wynveen PM Marc DT Olson KL Kellermann GH 《Analytical and bioanalytical chemistry》2012,402(4):1593-1600
Depression is a common disorder with physical and psychological manifestations often associated with low serotonin. Since
noninvasive diagnostic tools for depression are sparse, we evaluated the clinical utility of a novel ELISA for the measurement
of serotonin in urine from depressed subjects and from subjects under antidepressant therapy. We developed a competitive ELISA
for direct measurement of serotonin in derivatized urine samples. Assay performance was evaluated and applied to clinical
samples. The analytical range of the assay was from 6.7 to 425 μg serotonin/g creatinine (Cr). The limit of quantification
was 4.7 μg/g Cr. The average recovery for spiked urine samples was 104.4%. Average intra-assay variation was 4.4%, and inter-assay
variation was <20%. The serotonin analysis was very specific. No significant interferences were observed for 44 structurally
and nonstructurally related urinary substances. Very good correlation was observed between urinary serotonin levels measured
by ELISA and liquid chromatography tandem mass spectrometry (LC-MS/MS; ELISA = 1.16 × LC-MS/MS − 53.8; r = 0.965; mean % bias = 11%; n = 18). Serotonin was stable in acidified urine for 30 days at room temperature and at −20 °C. The established reference range
for serotonin was 54–366 μg/g Cr (n = 64). Serotonin levels detected in depressed patients (87.53 ± 4.89 μg/g Cr; n = 60) were significantly lower (p < 0.001) than in nondepressed subjects (153.38 ± 7.99 μg/g Cr). Urinary excretion of serotonin in depressed individuals significantly
increased after antidepressant treatment by 5-hydroxy-tryptophane and/or selective serotonin re-uptake inhibitor (p < 0.01). The present ELISA provides a convenient and robust method for monitoring urinary serotonin. It is suitable to monitor
serotonin imbalances and may be particularly helpful in evaluating antidepressant therapies. 相似文献
14.
A simple HPLC-MS/MS method for simultaneous determination of loureirin A and loureirin B in rat urine, feces, and bile after
oral administration of 10.6 g/kg of longxuejie (one rare traditional Chinese medicinal herb) was developed for the first time.
The analytes and buspirone (internal standard) were separated on a C5 column with acetonitrile–water (containing 0.1% formic acid) as mobile phase at a flow rate of 0.4 min/mL. The detector was
a Q-trap™ mass spectrometer with an electrospray ionization interface operating in the multiple reaction monitoring mode.
Calibration curves of loureirin A in rat urine, feces, and bile were linear over the concentration range of 1.00–5,000 ng/mL.
Loureirin B in rat urine, feces, and bile ranged between 0.08 and 20, 0.20 and 20, and 0.10 and 500 ng/mL, respectively. Validation
revealed that the method was specific, accurate, and precise. The fully validated method was applied to the excretion study
of loureirin A and loureirin B in rats. After oral administration of 10.6 g/kg longxuejie, cumulative excretion amount of
loureirin A and loureirin B in rat urine were 2.94 ± 0.81 and 0.36 ± 0.16 μg at 72 h, respectively. Of the total dose, 5.35%
of loureirin A and 5.46% of loureirin B were excreted from feces at 60 h. The cumulative amounts of loureirin A and loureirin
B in rat bile reached 4.49 ± 0.98 and 5.11 ± 0.83 μg, respectively, at 36 h after dosing, accounting for 0.054% and 0.056%
of the total dose. 相似文献
15.
P. Ünak F. Yurt Lambrecht F. Z. Biber S. Darcan 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):649-651
This study was designed to evaluate iodine concentrations in drinking water samples using isotope dilution analysis (IDA)
in the Aegean region of Turkey A total of 76 drinking water samples from rural and urban areas in regional cities were analyzed.
The mean iodine concentration was 78±27 μg/l and iodine concentration ranges were within 69±26 μg/l and 103±6 μg/l. 相似文献
16.
Lué-Merú Marcó Parra 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(2):479-484
The onion (Allium cepa L.) is one of the most important cultivars in the world and its production level occupies the second place in Venezuela.
It becomes important to develop analytical procedures for arsenic determination and to study the effect of this element on
the cultures, as well the absorption, transport and translocation processes. A TXRF method for As determination in onions
was developed. Two treatments were applied to the onion plants, As contaminated and control. The contaminant was added to
the plants to an amount of 100 μg, in a single time 3 weeks after the transplant of plantlets. The green leaves bulbs, and
roots together with the stems were separated 45 days after transplant and analyzed by TXRF and HG-AAS for total Arsenic determination.
A good agreement was found between these two techniques, demonstrating the accuracy of the TXRF procedure. It was found that
the highest concentration corresponded to the root and stems (37 ± 31 μg g−1), followed by the bulbs (11 ± 7 μg g−1), being the smallest level found in the green leaves (4 ± 3 μg g−1). At low As contamination levels of 0.25 μg g−1, a risk for translocation of the toxic element to the edible parts of the onion plants exists. At this level the normal development
of the plant is not affected, being the only exception the root length, which is significantly higher in the contaminated
treatment. 相似文献
17.
Joana P. N. Ribeiro Luís M. Magalhães Marcela A. Segundo Salette Reis José L. F. C. Lima 《Analytical and bioanalytical chemistry》2010,397(7):3005-3014
In the present work, a fluorimetric automatic method based on multisyringe flow injection analysis (MSFIA) was developed for
in vitro evaluation of scavenging capacity against nitric oxide (NO) using 4,5-diaminofluorescein (DAF-2) as an NO-selective
fluorogenic probe. The MSFIA manifold was assembled to perform the in-line generation of NO and the competitive reaction of
putative scavenger molecules and DAF-2 with NO at conditions close to those found in vivo regarding temperature (37°C), pH
(7.4), and concentration of NO (less than 1 μM). This approach allowed the evaluation of scavenging capacity against NO by
endogenous antioxidant molecules, pharmaceutical compounds, and human plasma. IC50 values were calculated for rutin (1.30 ± 0.02 μM, positive control), cysteine (321 ± 8 μM), reduced glutathione (1106 ± 93 μM),
uric acid (134 ± 12 μM), dipyrone (1.36 ± 0.06 μM), and captopril (363 ± 28 μM). A high degree of automation was attained
as the successive dilution of antioxidant standard solutions required for IC50 assessment was performed automatically, in a dilution chamber placed in the flow system. A determination throughput of 16 h-1 and a good precision were attained (relative standard deviation between 1.6 and 9.0%), fostering the application of the proposed
method to routine/screening analysis of scavenging capacity against NO. 相似文献
18.
F. Yurt Lambrecht K. Durkan E. Bayrak 《Journal of Radioanalytical and Nuclear Chemistry》2010,284(3):539-545
Bombesin (BNN)-like peptides have very high binding affinity for the gastrin-releasing peptide (GRP) receptor. The goal of
the current study was to optimize the labeling conditions of a new 99mTc-radiolabeled BNN-like peptide based on the bifunctional chelating ligand HYNIC using different co-ligands (EDDA and tricine).
The radiolabeling conditions (pH, amount of co-ligand, amount of stannous chloride, temperature and reaction time) for newly-formed
99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were optimized and evaluated by RHPLC and RTLC. Radiochemical yields for 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were 98.0 ± 1.7 and 97.5 ± 2.5%, respectively. When EDDA was used as co-ligand, the labeling of 99mTc-EDDA-HYNIC-Q-Litorin was optimal in the following reaction mixture: HYNIC-peptide: EDDA: 10 μg/5 mg, pH 3, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min. Besides, the optimum conditions were HYNIC-peptide:tricine:
10 μg/50 mg, pH 5, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min for preparing 99mTc-tricine-HYNIC-Q-Litorin. The manufactured 99mTc-HYNIC-Q-Litorin conjugates may offer new possibilities for imaging cancer cells expressing bombesin receptors. 相似文献
19.
Z. R. Turel J. R. Merchant B. C. Haldar 《Journal of Radioanalytical and Nuclear Chemistry》1978,45(1):203-207
Seeds of (the plant) P. Corylifolia Linn (Bawachi) known for their therepeutic value in indigenous medicine have been analysed
for Cu, As, Sb and Se by thermal neutron activation analysis involving substoichiometric extraction and precipitation technique.
The amounts of Cu, As, Sb and Se per gram of seeds dried at 80°C are 16.0±1.1 μg, 0.90±0.4 μg, 12.1±0.6 μg and 4.0±0.2 μg
respectively. 相似文献
20.
Theodora J. Stewart Jean-Huei Yau Mary M. Allen Daniel J. Brabander Nolan T. Flynn 《Colloid and polymer science》2009,287(9):1033-1040
Chronic exposure to Pb2+ above the 15-μg/L US Environmental Protection Agency action level for drinking water has been shown to cause a host of health
problems in humans. Thus, it is important to study new methods available for the treatment and removal of Pb2+ from drinking water and wastewater, where elevated levels of heavy metals are found. Alginate-based beads represent one such
possible method for heavy metal removal. The impact of alginate density on the equilibrium and kinetics of Pb2+ sorption onto hydrogel beads was investigated using Ca-alginate beads ranging from 1% to 8% (w/v) and exposed to Pb2+ concentrations ranging from 100 to 1,000 mg/L. When Ca-alginate beads were characterized using Fourier transform infrared
analysis, the carboxylic acid groups of the mannuronate and guluronate residues in alginate were the primary functional groups
that interacted with Pb2+. Hydration of Ca-alginate beads was also examined and found to decrease as Ca-alginate density increased. A positive correlation
was observed between Ca-alginate hydration and Pb2+ sorption. Sorption of Pb2+ was fast, reaching equilibrium after approximately 4 h, and is well described by the Langmuir adsorption isotherm. Maximum
sorption capacities for 1%, 4%, and 8% beads were 500 ± 100, 360 ± 30, and 240 ± 20 mg/g (dry weight), respectively. The kinetics
of sorption were best described by the pseudo-second-order Lagergren model, with rate constants determined as 3.2 ± 0.1 × 10−4, 1.0 ± 0.1 × 10−4, and 1.6 ± 0.1 × 10−4 g mg−1 min−1 for 1%, 4%, and 8% beads, respectively. 相似文献