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1.
Ernst Lücker Wolfgang Biedermann Thomas Alter Andreas Hensel 《Analytical and bioanalytical chemistry》2010,398(2):963-972
Methods for the detection of central nervous tissue (CNT) are urgently needed in food control as a means for controlling strict
adherence to both food labeling and banning of specified BSE risk material. Here, we report data on heat stability of the
CNT markers neuron-specific enolase (NSE) in western blotting, glial fibrillary acidic protein (GFAP) in an enzyme linked
immunoassay, mRNAGFAP in a real-time PCR assay, and several fatty acids (C22:6, C24:0-OH, C24:1ω9/ω7, C24:1ω9-OH/ω7-OH, and C24:0) in gas chromatography
mass spectrometry (GC/MS). The sample matrix, a standard material of emulsion-type sausage with varied contents of CNT (brain),
was heat-treated in three studies: (1) routine meat technological heat treatment with low (85 °C, 30 min), medium (115 °C,
30 min), and high (133 °C, 30 min, 3 bar) heating of 72 anonymous samples from a blind trial; (2) heat treatment under experimental
conditions (100, 110, …, 200 °C, 45 min); and (3) fractionized heating of central nervous system (up to three times) under
moderate routine technological conditions (85, 100, and 115 °C, 30 min). The markers of the immunochemical methods showed
a low GFAP or very low NSE temperature stability at medium and high temperature conditions. The real-time PCR assay gave inconsistent,
non-quantitative results, which indicated an uncontrollable matrix effect. The relevant GC/MS markers (C24:0-OH, C24:1ω9/ω7,
and C24:1ω9-OH/ω7-OH) proved to be extremely stable. Neither meat and bone meal conditions (133 °C) nor experimental heating
(up to and above 140 °C) showed any reduction of GC/MS CNT quantification. On the contrary, a slight but significant increase
was noted over a certain temperature range (120–140 °C) for most fatty acids, possibly due to an improved extractability of
the fatty acids. We conclude that a quantitative approach is highly unreliable when using immunochemical methods; moreover,
these methods might be basically prone to false-negative results depending on heat treatment and matrix composition. Therefore,
antibodies with higher affinity to heat-treated CNT marker epitopes are needed. Relevant amounts of CNT (≥0.5%) in low- and
medium-heated products would still be reliably detectable by the GFAP ELISA, which justifies its use as a screening method
in official food control. The results obtained by the real-time PCR assay were contradictory to recently published data, indicating
a need for further protocol optimization and collaborative trials. Up to date, the analytical approach using GC/MS is the
only valid procedure as pertaining to heat stability and quantitative analysis; consequently, it should be recommended as
the reference procedure in official food control for CNT detection in heat-treated meat products. 相似文献
2.
Simona Pafundo Mariolina Gullì Nelson Marmiroli 《Analytical and bioanalytical chemistry》2010,396(5):1831-1839
Thyroid hormones are essential hormones for regulating growth and development in humans and wildlife. Methods to monitor precise
and low levels of these hormones in serum and tissues are needed to assess overall health, whether from disease considerations
or possibly from environmental contaminant exposures. Common and routine methods typically rely upon radioimmunoassays, which
can be expensive, and typically only measure thyroxine and 3,3′,5-triidothyronine, which can be a limitation in fully evaluating
impacts on thyroid regulation. In this study we developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method
for the simultaneous analysis of five thyroid hormones—thyroxine, 3,3′,5-triidothyronine, 3,3′,5′-triiodothyronine, 3,3′-diiodothyronine,
and 3,5-diiodothyronine—in serum samples. The LC-MS/MS parameters were optimized and calibrated over a wide concentration
range (1.0–500 ng/mL) with on-column detection limits of 1.5–7.0 pg. With use of spiked bovine serum samples, the mean method
recoveries were calculated to be 81.3–111.9% with relative standard deviations of 1.2–9.6% at spiking levels ranging from
10 to 100 ng/mL. This method was compared with measurements made by standard radioimmunoassays and with measurements made
in a serum Standard Reference Material (SRM 1951b). Development of this method expands the capacity to measure thyroid hormones
by including a larger suite of thyroid hormones, and has promising applications for measuring catabolism of thyroid hormones
in vitro. 相似文献
3.
Gustavo Merola Stefano Gentili Franco Tagliaro Teodora Macchia 《Analytical and bioanalytical chemistry》2010,397(7):2987-2995
A simple procedure combining headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC/MS)
to detect and quantify amphetamines, ketamine, methadone, cocaine, cocaethylene and ∆9-tetrahydrocannabinol (THC) in hair is described. This procedure allows, in a single sample, even scant, analysis of drugs
requiring different analytical conditions. A hair sample (10 mg) is washed and subjected to acidic hydrolysis. Then the HS-SPME
is carried out (10 min at 90 °C) for amphetamines, ketamine, methadone, cocaine and cocaethylene. For derivatization of analytes,
the fibre is introduced into the headspace of another closed vial containing acetic anhydride. After a chromatographic run,
an alkaline hydrolysis for THC analysis is carried out in the same vial containing the hair sample previously used. For adsorption,
the solid-phase microextraction needle is inserted into the headspace of the vial and the fibre is exposed for 30 min at 150 °C.
For derivatization of analytes, the fibre is introduced into the headspace of another closed vial containing N-methyl-N-(trimethylsilyl)trifluoroacetamide. The GC/MS parameters were the same for both chromatographic runs. The linearity was proved
to be between 0.01 and 10.00 ng/mg. The repeatability (intra- and interday precision) was below 10% as the coefficient of
variation for all compounds. The accuracy, as the relative recovery, was 96.2–103.5% (spiked samples) and 88.6–101.7% (quality
control sample). The limit of detection ranged from 0.01 to 0.12 ng/mg, and the limit of quantification ranged from 0.02 to
0.37 ng/mg. Application of the procedure to real hair samples is described. To the best of our knowledge, the proposed procedure
combining HS-SPME and GC/MS is the first one be to successfully applied to the simultaneous determination of most of the common
recreational drugs, including THC, in a single hair sample. 相似文献
4.
González-Gago A Brandsma SH Leonards PE de Boer J Marchante-Gayón JM Garcia Alonso JI 《Analytical and bioanalytical chemistry》2011,401(8):2639-2649
A gas chromatography electron capture negative ionization mass spectrometry (GC(ECNI)MS) procedure for the determination of
priority polybrominated diphenyl ethers (PBDEs; congeners 28, 47, 99, 100, 153 and 154) in water samples at regulatory EU
levels has been developed. The method is based on the use of 81Br-labelled PBDEs for isotope dilution analysis and the measurement of 79Br/81Br isotope ratios in gas chromatography peaks with the electron capture negative ionization technique. The suitability of
this ion source for the precise and accurate measurement of bromine isotope ratios has been demonstrated. The general ECNI-IDMS
procedure was evaluated by the analysis of NIST SRM 1947 (Lake Michigan fish tissue) with satisfactory results. For the analysis
of water samples, 500 mL of the samples were spiked with the labelled PBDEs and extracted with 10 mL isooctane for 30 min.
The extract was evaporated down to ca. 100 μL and injected in the GC(ECNI)MS. Detection limits ranged from 0.014 −1 to 0.089 pg mL−1 depending on the congener. Recoveries from real water samples, spiked at a level of 0.5 pg mL−1, ranged from 77% to 102%. 相似文献
5.
R. Jeannot H. Sabik L. Amalric E. Sauvard S. Proulx B. Rondeau 《Chromatographia》2001,54(3-4):236-240
Summary A method has been developed for determination of twenty-four polar pesticides—nine organophosphorus pesticides, thirteen organonitrogen
compounds, and two triazine degradation products—in surface water. It entails extraction of the target pesticides from 1-L
water samples by solid-phase extraction (SPE), then gas chromatography (GC) with large-volume (40 μL) injection. Filtered
surface water, from the St Lawrence River in Canada and the River Loire and its tributaries in France, was extracted on cartridges
filled with 500 mg Carbopack B (120–400 mesh). Analysis was performed by gas chromatography with a thermionic specific detector
(GC-TSD) and a mass spectrometric (MS) detector. Overall percentage recoveries were satisfactory (>70%) for all target pesticides,
with precision below 10%. Detection limits were between 0.5 and 4 ng L−1. 相似文献
6.
H. Gnann C. Engelmann G. Skopp M. Winkler V. Auwärter S. Dresen N. Ferreirós F. M. Wurst W. Weinmann 《Analytical and bioanalytical chemistry》2010,396(7):2415-2423
Phosphatidylethanol (PEth) is an abnormal phospholipid carrying two fatty acid chains. It is only formed in the presence of
ethanol via the action of phospholipase D (PLD). Its use as a biomarker for alcohol consumption is currently under investigation.
Previous methods for the analysis of PEth included high-performance liquid chromatography (HPLC) coupled to an evaporative
light scattering detector (ELSD), which is unspecific for the different homologues—improved methods are now based on time
of flight mass spectrometry (TOF-MS) and tandem mass spectrometry (MS/MS). The intention of this work was to identify as many
homologues of PEth as possible. A screening procedure using multiple-reaction monitoring (MRM) for the identified homologues
has subsequently been established. For our investigations, autopsy blood samples collected from heavy drinkers were used.
Phosphatidylpropanol 16:0/18:1 (internal standard) was added to the blood samples prior to liquid–liquid extraction using
borate buffer (pH 9), 2-propanol and n-hexane. After evaporation, the samples were redissolved in the mobile phase and injected into the LC-MS/MS system. Compounds
were separated on a Luna Phenyl Hexyl column (50 mm × 2 mm, 3 μm) by gradient elution, using 2 mM ammonium acetate and methanol/acetone
(95/5; v/v). A total of 48 homologues of PEth could be identified by using precursor ion and enhanced product ion scans (EPI). 相似文献
7.
Melanie Jünger Bertram Bödeker Jörg Ingo Baumbach 《Analytical and bioanalytical chemistry》2010,396(1):471-482
Over the past years, ion mobility spectrometry (IMS) as a well established method within the fields of military and security
has gained more and more interest for biological and medical applications. This highly sensitive and rapid separation technique
was crucially enhanced by a multi-capillary column (MCC), pre-separation for complex samples. In order to unambiguously identify
compounds in a complex sample, like breath, by IMS, a reference database is mandatory. To obtain a first set of reference
data, 16 selected volatile organic substances were examined by MCC-IMS and comparatively analyzed by the standard technique
for breath research, thermal desorption–gas chromatography–mass spectrometry. Experimentally determined MCC and GC retention
times of these 16 compounds were aligned and their relation was expressed in a mathematical function. Using this function,
a prognosis of the GC retention time can be given very precisely according to a recorded MCC retention time and vice versa.
Thus, unknown MCC-IMS peaks from biological samples can be assigned—after alignment via the estimated GC retention time—to
analytes identified by GC/MS from equivalent accomplished data. One example of applying the peak assignment strategy to a
real breath sample is shown in detail. 相似文献
8.
A rapid and high-throughput isotope dilution LC-MS/MS method with online sample pre-concentration and clean-up using anionic mixed-mode SPE was described for the determination of closantel and rafoxanide in edible bovine and ovine tissues. Tissue samples were extracted with acetonitrile and acetone mixture (60:40, v/v). Sample pre-concentration, clean-up and analysis were completed simultaneously with the online MAX SPE LC-MS/MS system. Closantel-(13) C(6) and rafoxanide-(13) C(6) were used as the internal standards to improve the precision of the method. The method was validated with edible ovine and bovine tissues (muscle, kidney and liver) fortified at three different levels. The accuracy and RSD were 86-106% and ≤14%, respectively. This high-throughput method was suitable for routine quantitative analysis of closantel and rafoxanide in food safety surveillance samples. 相似文献
9.
Certified reference material for quantification of polycyclic aromatic hydrocarbons in sediment from the National Metrology Institute of Japan 总被引:2,自引:0,他引:2
Nobuyasu Itoh Yoshie Aoyagi Akiko Takatsu Takashi Yarita 《Analytical and bioanalytical chemistry》2009,393(8):2039-2049
The National Metrology Institute of Japan has issued a certified reference material (CRM) of freshwater lake sediment for
polycyclic aromatic hydrocarbon (PAHs) analyses. The certification used three extraction techniques: pressurized liquid extraction
(PLE) with toluene, PLE with dichloromethane/ethyl acetate (1:1 by volume), and alkaline extraction (1 M KOH in methanol)
in combination with microwave-assisted extraction. Both gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/dopant-assisted
atmospheric pressure photoionization/MS (LC/DA-APPI/MS) analyses were used. Certified values are provided for 18 PAHs at 1–25 μg
kg−1 except for perylene (2.08 × 103 μg kg−1), and information values are provided for two. Since the values of PAHs in the CRM are much lower than those in other CRMs
and are comparable to those found at sites with little human influence, the CRM is suitable for PAH monitoring in sediment
and soil samples. 相似文献
10.
Pan Du Yanmao Shi Ping Wu Yaoming Zhou Chenxin Cai 《Frontiers of Chemistry in China》2007,2(4):369-377
It was reported that carbon nanotube (CNT) was functionalized with the electroactive Nile blue (NB), which is a phenoxazine
dye, by a method of adsorption to form a NB-CNT nanocomposite. The NB-CNT nanocomposite was characterized by several spectroscopic
techniques, for example, Ultraviolet-visible spectroscopy (UV-VIS), Fourier transform infrared (FTIR), Raman spectroscopy
and scanning electron microscopy (SEM) etc., and the results showed that NB could rapidly and effectively be adsorbed on the
surface of CNT with a high stability without changing the native structure of NB and the structure properties of CNT. Moreover,
it was shown that the dispersion ability of CNT in aqueous solution had a significantly improvement after CNT functionalized
with NB even at a level of high concentration, for example, 5 mg of NB-CNT per 1 mL of H2O. The NB-CNT/ glasssy carbon (GC) electrode was fabricated by modifying NB-CNT nanocomposite on the GC electrode surface
and its electrochemical properties were investigated by cyclic voltammetry. The cyclic voltammetric results indicate that
CNT can improve the electrochemical behavior of NB and greatly enhance its redox peak currents. While the NB-CNT/GC electrode
exhibited a pair of well-defined and nearly symmetrical redox peaks with the formal potential of (−0.422±0.002) V (versus
SCE, 0.1 mol/L PBS, pH 7.0), which was almost independent on the scan rates, for electrochemical reaction of NB monomer; and
the redox peak potential of NB polymer located at about −0.191 V. The experimental results also demonstrated that NB and CNT
could synergistically catalyze the electrochemically oxidation of NADH (β-nicotinamide adenine dinucleotide, reduced form) and NB-CNT exhibited a high performance with lowing the overpotential of
more than 560 mV. The NB-CNT/GC electrode could effectively sense the concentration of NADH, which was produced during the
process of oxidation of substrate (e.g. ethanol) catalyzed by dehydrogenase (e.g. alcohol dehydrogenase). The presented method
for functionalization of CNT had several advantages, such as rapid and facile CNT functionalization, easy electrode fabrication
and high electrocatalytic activity, etc., and could be used for fabrication electrochemical biosensor on the basis of dehydrogenase.
__________
Translated from Acta Chimica Sinica, 2007, 65(1): 1–9 [译自: 化学学报] 相似文献
11.
Guzel Ziyatdinova Aliya Gainetdinova Mikhail Morozov Herman Budnikov Svetlana Grazhulene Arkady Red’kin 《Journal of Solid State Electrochemistry》2012,16(1):127-134
Glassy carbon electrodes (GCE) modified with carbon nanotubes (CNT) have been created for detection of phenolic compounds—one
of the important group of antioxidants in life sciences. The surface of electrode has been characterized by atomic force microscopy.
The presence of CNT leads to an at least 20-fold increase in the surface roughness of the electrode. The CNT layer displays
closely intertwined vermicular structures with high degree of homogeneity at CNT suspension concentration of 0.2–0.5 mg L−1. Synthetic water-soluble antioxidants (hydroquinone, catechol, pyrogallol, and their derivatives) are electrochemically active
on bare GCE and CNT-modified GCE in phosphate buffer solution pH 7.4. Effect of substitutes in molecular structure of phenolic
antioxidants has been evaluated. In several cases, oxidation at CNT-modified GCE occurs at potentials that are less positive
by 100–200 mV in comparison to bare GCE. The electrodes were studied with respect to their capability of phenols voltammetric
sensing. CNT-modified GCE display an enlarged linear range in the calibration graphs and lower detection limits. Voltammetric
method for determination of hydroquinone, catechol, pyrogallol, and their derivatives has been developed. 相似文献
12.
E. Pitarch T. Portolés J. M. Marín M. Ibáñez F. Albarrán F. Hernández 《Analytical and bioanalytical chemistry》2010,397(7):2763-2776
The presence of a wide variety of organic pollutants with different physicochemical characteristics has been investigated
in wastewater samples from a municipal solid-waste-treatment plant in Castellón, Spain. An advanced analytical strategy was
applied—combined used of two powerful and complementary techniques, GC and LC, both hyphenated with tandem mass spectrometry
with triple-quadrupole analyzers. The GC–MS–MS method was based on sample extraction using C18 SPE cartridges and enabled the determination of approximately 60 compounds from different chemical families, for example
PAHs, octyl/nonylphenols, PCBs, organochlorine compounds, insecticides, herbicides, and PBDEs. Most of the compounds selected
are included as priority contaminants in the European Union (EU) Water Directive. The UHPLC–MS–MS method, which provided high
chromatographic resolution and sensitivity and short analysis time, used sample extraction with Oasis HLB SPE cartridges and
enabled the determination of 37 (more polar) pesticides. The methodology developed was applied to the analysis of 41 water
samples (20 untreated raw leachates and 21 treated samples) collected between March 2007 and February 2009. Amounts of the
contaminants investigated rarely exceeded 0.5 μg L−1 in the treated (reverse osmosis) water samples analyzed. As expected, in untreated leachates the number of compounds detected
and the concentrations found were notably higher than in treated waters. The most commonly detected pollutants were herbicides
(simazine, terbuthylazine, terbutryn, terbumeton, terbacil, and diuron), fungicides (thiabendazole and carbendazim), and 4-t-octylphenol. The results obtained proved that use of reverse osmosis for water treatment was efficient and notably reduced
the amounts of organic contaminants found in raw leachate samples. In order to investigate the presence of other non-target
contaminants, water samples were also analyzed by using GC–TOF MS and LC–QTOF MS. Several organic pollutants that did not
form a part of the previous list of target contaminants were identified in the samples, because of the high sensitivity of
TOF MS in full-spectrum acquisition mode and the valuable accurate-mass information provided by these instruments. The insecticide
diazinon, the fungicide diphenylamide, the UV filter benzophenone, N-butylbenzenesulfonamide (N-BBSA), the insect repellent diethyltoluamide, caffeine, and the pharmaceuticals erythromycin,
benzenesulfonanilide, ibuprofen, atenolol, and paracetamol were some of the compounds identified in the water samples analyzed. 相似文献
13.
Qian M Wu L Zhang H Xu M Li R Wang X Sun C 《Analytical and bioanalytical chemistry》2012,402(7):2451-2462
A new sensitive multiresidue liquid chromatography–tandem mass spectrometry (LC-MS/MS) analytical method for the determination
of 16 insect growth regulator (IGR) residues—RH-5849 (1,2-dibenzoyl-1-tert-butylhydrazine), halofenozide, methoxyfenozide, chromafenozide, fufenozide, tebufenozide, diflubenzuron, chlorbenzuron, triflumuron,
hexaflumuron, novaluron, lufenuron, teflubenzuron, flucycloxuron, flufenoxuron, and chlorfluazuron—in herbs (Perilla frutescens, flos chrysanthemi, lily bulbs, and ginger) has been developed. After the herbs had been extracted with acetonitrile, a combined
graphitized nonporous carbon/aminopropyl (ENVI-Carb/LC-NH2) cartridge and a Florisil cartridge were used to clean up the extracts. LC-MS/MS was performed in multiple reaction monitoring
mode with two specific precursor ion–product ion transitions per IGR to confirm and quantitate the residues in herbs. Quantitation
was performed on the basis of matrix-matched calibrations. The method showed excellent linearity (r
2 > 0.99) and precision (relative standard deviations of 13.6 or lower) for all the target insecticides. The limits of quantitation
were 0.6-10 μg kg-1 for the 16 insecticides in the four herbs. The average recoveries, measured at three concentrations (0.01, 0.1, 1 mg kg-1), were in the range 74.8-105.3%. The method was satisfactorily applied for the analysis of 60 herb samples (Perilla frutescens, flos chrysanthemi, lily bulbs, and ginger). Hexaflumuron was detected at concentrations of 0.029 and 0.051 mg kg-1 in Perilla frutescens. 相似文献
14.
Dispersive liquid—liquid microextraction coupled with high-performance liquid chromatography—diode-array detection was applied
for the extraction and determination of 11 priority pollutant phenols in wastewater samples. The analytes were extracted from
a 5-mL sample solution using a mixture of carbon disulfide as the extraction solvent and acetone as the dispersive solvent.
After extraction, solvent exchange was carried out by evaporating the solvent and then reconstituting the residue in a mixture
of methanol–water (30:70). The influences of different experimental dispersive liquid—liquid microextraction parameters such
as extraction solvent type, dispersive solvent type, extraction and dispersive solvent volume, salt addition, and pH were
studied. Under optimal conditions, namely pH 2, 165-μL extraction solvent volume, 2.50-mL dispersive solvent volume, and no
salt addition, enrichment factors and limits of detection ranged over 30–373 and 0.01–1.3 μg/L, respectively. The relative
standard deviation for spiked wastewater samples at 10 μg/L of each phenol ranged between 4.3 and 19.3% (n = 5). The relative recovery for wastewater samples at a spiked level of 10 μg/L varied from 65.5 to 108.3%. 相似文献
15.
A. A. M. Stolker M. J. Groot J. J. P. Lasaroms A. W. J. M. Nijrolder M. H. Blokland I. Riedmaier C. Becker H. H. D. Meyer M. W. F. Nielen 《Analytical and bioanalytical chemistry》2009,395(4):1075-1087
The abuse of synthetic esters of natural steroids such as testosterone and estradiol in cattle fattening and sports is hard
to detect via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously
present in urine. An interesting alternative can be provided by the analysis of the administered synthetic steroids themselves,
i.e., the analysis of intact steroid esters in hair by liquid chromatography tandem mass spectrometry (LC/MS/MS). However,
retrospective estimation of the application date following a non-compliant finding is hindered by the complexity of the kinetics
of the incorporation of steroid esters in hair. In this study, the incorporation of intact steroid esters in hair following
pour-on treatment has been studied and critically compared with results from intramuscular treatment. To this end animals
were pour-on treated with a hormone cocktail containing testosterone cypionate, testosterone decanoate and estradiol benzoate
in different carriers. The animals were either treated using injection and pour-on application once or three times having
1 week between treatments using injection and pour-on application. Animals were slaughtered from 10–12 weeks after the last
treatment. Both hair and blood plasma samples were collected and analysed by LC/MS/MS. From the results, it is concluded that
after single treatment the levels of steroid esters in hair drop to CCβ levels (5–20 μg/kg) after 5–7 weeks. When treatment
is repeated two times, the CCβ levels are reached after 9–11 weeks. Furthermore, in plasma, no steroid esters were detected;
not even at the low microgramme per litre level but—in contrast with the pour-on application—after i.m. injection, significant
increase of 17β-testosterone and 17β-estradiol were observed. These observations suggest that transport of steroid esters
after pour-on application is not only performed by blood but also by alternative fluids in the animal so probably the steroid
esters are already hydrolysed and epimerized before entering the blood. 相似文献
16.
P. López S. Martello A. M. Bermejo Eleonora De Vincenzi M. J. Tabernero M. Chiarotti 《Analytical and bioanalytical chemistry》2010,397(4):1539-1548
This article describes an easy and innovative extraction procedure for cocaine and its primary metabolite, benzoylecgonine
(BE), from hair consisting of sonication with H2O/0.1% formic acid for 4 h. The same extract was used for screening with an enzyme-linked immunoassay (ELISA) and confirmation
by liquid chromatography–tandem mass spectrometry (LC–MS/MS). For the ELISA screening test a cutoff of 0.5 ng/mg was used
according to the Society of Hair Testing recommendations. LC–MS/MS limits of detection (LODs) were established to be 10 pg/mg
and 1 pg/mg for cocaine and BE, respectively. Linearity was obtained over a range of 0.2–5 ng/mg for BE (target analyte) in
the ELISA screening test, while in the LC–MS/MS method the range was 0.10–10 ng/mg for cocaine and 0.01–10 ng/mg for BE. Intra-
and interbatch coefficients of variation and mean relative errors were less than 20% for all analytes and concentrations studied.
The validated ELISA and LC–MS/MS methods were applied to 48 hair samples and the results of both methods were compared; ELISA
demonstrated a sensitivity and specificity of 89.2% and 10.8%. 相似文献
17.
Huang Q Xu T Wang GY Huang JF Xia H Yin R Tang A Fu WL 《Analytical and bioanalytical chemistry》2012,402(4):1625-1634
Ever since the emergence of bovine spongiform encephalopathy, the source of pharmaceutical heparin has been restricted to
porcine intestinal mucosa. In this project, two real-time fluorescent PCR methods were developed to assist with quality control
analysis. The first is a qualitative method which relies on SYBR Green I chemistry to confirm the porcine origin of industrial
crude porcine heparin (ICPH), identify any ruminant contaminants, and generally control purity. The second is based on TaqMan
chemistry and is able to quantitatively identify porcine, bovine, caprine, and ovine components and contaminants in ICPH.
By targeting mitochondrial DNA, both PCR systems showed a detection limit of 1 pg DNA and amplification efficiencies ranging
between 96% and 102%. Moreover, quantitative PCR showed a detection limit of 0.02 ppm in samples comprising porcine, bovine,
caprine, and ovine DNA. The results of qualitative PCR over 27 ICPH samples showed that all samples were porcine in origin
and that 17 had ruminant contaminants. The results of quantitative PCR further showed that out of all 17 samples with ruminant
contaminants, seven samples had bovine, ovine, and caprine contaminants, two samples had bovine and ovine contaminants, and
eight samples had only ovine contaminants. In conclusion, the qualitative PCR system was found to be a relatively inexpensive,
rapid, and flexible method of identifying the porcine origin of and ruminant contaminants in ICPH, while the quantitative
PCR was found suitable to accurately analyze the components and contaminants in detail. Both methods are suitable for routine
control assays for the evaluation of ICPH purity and origins of contaminants. 相似文献
18.
Min Jung Kim Hyeon A. Ki Won Young Kim Sukdeb Pal Byeong Keun Kim Woo Suk Kang Joon Myong Song 《Analytical and bioanalytical chemistry》2010,398(2):943-953
The effects of high dose γ-irradiation on six herbal medicines were investigated using gas chromatography–mass spectrometry
(GC/MS) and high-performance liquid chromatography (HPLC). Herbal medicines were irradiated at 0–50 kGy with 60Co irradiator. HPLC was used to quantify changes of major components including glycyrrhizin, cinnamic acid, poncirin, hesperidin,
berberine, and amygdalin in licorice, cinnamon bark, poncirin immature fruit, citrus unshiu peel, coptis rhizome, and apricot
kernel. No significant differences were found between gamma-irradiated and non-irradiated samples with regard to the amounts
of glycyrrhizin, berberine, and amygdalin. However, the contents of cinnamic acid, poncirin, and hesperidin were increased
after irradiation. Volatile compounds were analyzed by GC/MS. The relative proportion of ketone in licorice was diminished
after irradiation. The relative amount of hydrocarbons in irradiated cinnamon bark and apricot kernel was higher than that
in non-irradiated samples. Therefore, ketone in licorice and hydrocarbons in cinnamon bark and apricot kernel can be considered
radiolytic markers. Three unsaturated hydrocarbons, i.e., 1,7,10-hexadecatriene, 6,9-heptadecadiene, and 8-heptadecene, were
detected only in apricot kernels irradiated at 25 and 50 kGy. These three hydrocarbons could be used as radiolytic markers
to distinguish between irradiated (>25 kGy) and non-irradiated apricot kernels. 相似文献
19.
Russo MV Notardonato I Cinelli G Avino P 《Analytical and bioanalytical chemistry》2012,402(3):1373-1381
A solid-phase extraction (SPE) method was developed for extraction and analysis of six phthalate esters in wine samples using
Carbograph 1 sorbent. The SPE procedure allowed efficient recovery of the investigated phthalates ranging between 78% and
105% with a relative standard deviation (RSD) ≤6.5 for an ethanolic phthalic acid ester (PAE) standard solution and between
73–71% and 96–99% with a RSD ≤8.4 for red wine samples spiked with 20 and 50 ng mL−1 of PAE, respectively. The adsorption isotherms and breakthrough curves for Carbograph 1/water solution were reported. Gas
chromatography coupled with an ion-trap mass spectrometer detector (GC/IT-MS) was used for analysis. The instrumental analytical
protocol was found to yield a linear calibration in the range 0.01-10.0 μg mL−1 with R
2 values ≥0.9992. The limits of detection in GC/IT-MS (SIM mode) vary between 0.2 and 14 ng mL−1 (RSD ≤5.6) whereas the limits of quantification range between 0.5 and 25 ng mL−1 (RSD ≤5.9); the intra- and inter-day repeatabilities calculated as RSD for wine samples, were between 0.9–7.8 and 1.0–10.5,
respectively. The analytical method developed was applied to several commercial wine samples. Furthermore, the investigated
methods are simple, reliable, reproducible, and not expensive. 相似文献
20.
An enzyme-linked immunosorbent assay (ELISA) method was developed to quantitatively measure 2,4-dichlorophenoxyacetic acid (2,4-D) in human urine. Samples were diluted (1:5) with phosphate-buffered saline containing 0.05% Tween and 0.02% sodium azide, with analysis by a 96-microwell plate immunoassay format. No clean up was required as dilution step minimized sample interferences. Fifty urine samples were received without identifiers from a subset of pesticide applicators and their spouses in an EPA pesticide exposure study (PES) and analyzed by the ELISA method and a conventional gas chromatography/mass spectrometry (GC/MS) procedure. For the GC/MS analysis, urine samples were extracted with acidic dichloromethane (DCM); methylated by diazomethane and fractionated by a Florisil solid phase extraction (SPE) column prior to GC/MS detection. The percent relative standard deviation (%R.S.D.) of the 96-microwell plate triplicate assays ranged from 1.2 to 22% for the urine samples. Day-to-day variation of the assay results was within ±20%. Quantitative recoveries (>70%) of 2,4-D were obtained for the spiked urine samples by the ELISA method. Quantitative recoveries (>80%) of 2,4-D were also obtained for these samples by the GC/MS procedure. The overall method precision of these samples was within ±20% for both the ELISA and GC/MS methods. The estimated quantification limit for 2,4-D in urine was 30 ng/mL by ELISA and 0.2 ng/mL by GC/MS. A higher quantification limit for the ELISA method is partly due to the requirement of a 1:5 dilution to remove the urine sample matrix effect. The GC/MS method can accommodate a 10:1 concentration factor (10 mL of urine converted into 1 mL organic solvent for analysis) but requires extraction, methylation and clean up on a solid phase column. The immunoassay and GC/MS data were highly correlated, with a correlation coefficient of 0.94 and a slope of 1.00. Favorable results between the two methods were achieved despite the vast differences in sample preparation. Results indicated that the ELISA method could be used as a high throughput, quantitative monitoring tool for human urine samples to identify individuals with exposure to 2,4-D above the typical background levels. 相似文献