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1.
Glutathione peroxidase (isolated from bovine erythrocytes) and its behaviour during alkylation and enzymatic digestion were
studied by various hyphenated techniques: gel electrophoresis–laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry
(MS), size-exclusion liquid chromatography–ICP MS, capillary high-performance liquid chromatography (capHPLC)–ICP MS, matrix-assisted
laser desorption/ionization (MALDI) time-of-flight (TOF) MS, electrospray MS, and nanoHPLC–electrospray ionization (ESI) MS/MS.
ESI TOF MS and MALDI TOF MS allowed the determination of the molecular mass but could not confirm the presence of selenium
in the protein. The purity of the protein with respect to selenium species could be evaluated by LA ICP MS and size-exclusion
chromatography (SEC)–ICP MS under denaturating and nondenaturating conditions, respectively. SEC–ICP MS and capHPLC–ICP MS
turned out to be valuable techniques to study the enzymolysis efficiency, miscleavage and artefact formation during derivatization
and tryptic digestion. For the first time the parallel ICP MS and ESI MS/MS data are reported for the selenocysteine-containing
peptide extracted from the gel; capHPLC–ICP MS allowed the sensitive detection of the selenopeptide regardless of the matrix
and nanoHPLC–electrospray made possible its identification.
Figure Eye catching image
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Tastet L Schaumlöffel D Bouyssiere B Lobinski R 《Analytical and bioanalytical chemistry》2006,385(5):948-953
A method based on ICP collision-cell MS detection in capillary HPLC was developed to gain an insight into the purity and identity of selenium-containing proteins separated by 1-D and 2-D electrophoresis. The bands and spots obtained after the separation of water-soluble proteins in selenized yeast were digested with trypsin prior to chromatography. Selenium could be detected down to the subpicogram level. The method, assisted by information obtained by MALDI TOF MS on the 5000 Da cut-off fraction, permitted the purity of bands and spots to be estimated and the efficiency of tryptic digestion and the quantity of selenium present in individual peptides to be evaluated. Owing to the high sensitivity and the lack of matrix suppression effects, the method provided chromatograms with signal-to-noise ratios of 10–1000 in conditions where the common ES Q–TOF MS detection failed.
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3.
In-torch LA–ICP–MS was implemented into an in-house-built ICP–TOFMS system. The fast data acquisition capabilities of the
new configuration allowed simultaneous multi-element measurement and readout of in-torch LA–ICP–MS signals with 30 μs time
resolution. The measurements confirmed previously observed fine structures of in-torch generated signals and provided new
insights in the dynamic processes in the plasma on a microsecond time scale. The new setup is described in detail and first
figures of merit are given.
Figure Time dependent multi element signal after laser ablation in the torch of an ICP-TOFMS instrument 相似文献
4.
Van Lierde V Chéry CC Roche N Monstrey S Moens L Vanhaecke F 《Analytical and bioanalytical chemistry》2006,384(2):378-384
Since the species that trigger chromium allergy are not yet known, it is important to gain more of an insight into the mechanism
of chromium transport through the skin and into the relationship between chromium allergy and chromium species. In vitro permeation
studies with porcine and human skin were performed using a Franz static diffusion cell. Investigations attempted to elucidate
(i) which Cr compounds are able to permeate through skin, (ii) the influence the Cr concentration in the donor solution has
on the Cr permeation, and (iii) the effect that the time of exposure to the donor solution has on Cr permeation. Capillary
electrophoresis hyphenated to inductively coupled plasma–sector field mass spectrometry (CE–ICP–SFMS) was used to separate
and quantify the Cr species in the receptor fluid. 50 mmol L−1 phosphate buffer (pH 2.5) was used for CE separation, and two different electrophoretic runs were carried out (in the positive
and negative modes). Pneumatic nebulization (PN)-ICP-SFMS was used in order to quantify the total amount of Cr absorbed by
the skin after microwave-assisted acid digestion of the tissue. Cr(VI) was found to pass most easily through the skin. Nevertheless,
Cr(VI) was also shown to be absorbed more efficiently by the skin than Cr(III), an observation attributed to a more pronounced
rejection of the positively charged Cr(III) ions by the skin barrier. These results were in good agreement with in vitro permeation
studies previously reported in the literature in which other analytical techniques were used. Differences observed in the
permeation of Cr following the application of aqueous Cr donor solutions and Cr-containing simulated sweat donor solutions
are also described.
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5.
An X-ray fluorescence method (XRF) is presented that allowed low detection limits (at the 0.1–23 ng mL−1 level) to be obtained for Cr, Mn, Fe, Ni, Zn, Sr, Pb, Bi and Br in water. The samples were prepared using a thin layer method. Trace elements were determined via the calibration curve and standard addition. Absorption effects and inhomogenities in prepared samples were checked for using the emission–transmission method and internal standards, respectively. The results from the XRF method were compared with the results from the inductively coupled plasma atomic emission spectrometry method.
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6.
Francis Canon Franck Paté Emmanuelle Meudec Thérèse Marlin Véronique Cheynier Alexandre Giuliani Pascale Sarni-Manchado 《Analytical and bioanalytical chemistry》2009,395(8):2535-2545
Numerous protein–polyphenol interactions occur in biological and food domains particularly involving proline-rich proteins,
which are representative of the intrinsically unstructured protein group (IUP). Noncovalent protein–ligand complexes are readily
detected by electrospray ionization mass spectrometry (ESI-MS), which also gives access to ligand binding stoichiometry. Surprisingly,
the study of interactions between polyphenolic molecules and proteins is still an area where ESI-MS has poorly benefited,
whereas it has been extensively applied to the detection of noncovalent complexes. Electrospray ionization mass spectrometry
has been applied to the detection and the characterization of the complexes formed between tannins and a human salivary proline-rich
protein (PRP), namely IB5. The study of the complex stability was achieved by low-energy collision-induced dissociation (CID)
measurements, which are commonly implemented using triple quadrupole, hybrid quadrupole time-of-flight, or ion trap instruments.
Complexes composed of IB5 bound to a model polyphenol EgCG have been detected by ESI-MS and further analyzed by MS/MS. Mild
ESI interface conditions allowed us to observe intact noncovalent PRP–tannin complexes with stoichiometries ranging from 1:1
to 1:5. Thus, ESI-MS shows its efficiency for (1) the study of PRP–tannin interactions, (2) the determination of stoichiometry,
and (3) the study of complex stability. We were able to establish unambiguously both their stoichiometries and their overall
subunit architecture via tandem mass spectrometry and solution disruption experiments. Our results prove that IB5·EgCG complexes
are maintained intact in the gas phase.
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7.
Oberacher H 《Analytical and bioanalytical chemistry》2008,391(1):135-149
After completion of the human genome sequence the search for differences among individual genomes has become the centre of
focus for geneticists. Two different types of polymorphism—single nucleotide polymorphisms (SNPs) and short tandem repeats
(STRs)—are major sources of genetic diversity and are of widespread use in genetic analysis. A plethora of genotyping techniques
have been developed, and mass spectrometry (MS) is among the most widely used analytical platforms. The most striking advantage
of mass spectrometric genotyping assays over others is the use of the measured molecular mass information for allele calling.
The molecular mass is less error-prone than other sequence-specific parameters, including migration times, retention times,
or hybridization yields, as it represents an intrinsic property of a nucleic acid molecule that is directly related to its
nucleotide composition. Mass spectrometric assays can roughly be divided into two major groups—matrix-assisted laser desorption/ionization
(MALDI)-based and electrospray ionization (ESI)-based assays. An important subdivision of ESI-based genotyping methods are
approaches that originate from the hyphenation of liquid chromatography (LC) to MS. The principles of these three classes
of mass spectrometric genotyping techniques are summarized in this review. Possibilities and limitations are critically discussed
to assist scientists, especially non-experts in MS, in choosing the appropriate mass spectrometric assay for genotyping a
genetic marker of interest.
Figure Comparison of the principle workflows applied for the characterization of genetic markers by MALDI–MS, ESI–MS, and LC–MS 相似文献
8.
Hongjuan Dong Jasmin Kemptner Martina Marchetti-Deschmann Christian Peter Kubicek Günter Allmaier 《Analytical and bioanalytical chemistry》2009,395(5):1373-1383
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) has been proved to be a powerful
tool for the identification and characterization of microorganisms based on their surface peptide/protein pattern. Because
of the complexity of microorganisms, there are no standardized protocols to acquire reproducible peptide/protein profiles
for a broad range of microorganisms and for fungi in particular. Small variations during MALDI MS sample preparation affect
the quality of mass spectra quite often. In this study, we were aiming to develop a sample preparation method for the analysis
of colored, a quite often observed phenomenon, and mycotoxin-producing Fusarium conidia spores using MALDI–TOF MS. Different washing solvent systems for light- and deep-colored (from slightly orange to
red-brown) conidia spores and connected sample deposition techniques were evaluated based on MS reproducibility and number
and intensities of peaks. As a method of choice for generation of reproducible and characteristic MALDI–TOF mass spectra,
the use of a washing process for colored Fusarium conidia spores with acetonitrile/0.5% formic acid (7/3) was found and subsequently combined with two-layer volume technique
(spores/matrix (ferulic acid) solution was deposited onto a MALDI target, and after solvent evaporation, a second matrix layer
was deposited). With the application of this sample preparation method, for deep-colored Fusarium species, 19 abundant molecular ions in the m/z range 2,000–10,000 were always detected with an S/N ratio of 3:1 or better. Finally this optimized sample preparation for
the first time provided mass spectrometric fingerprints of strongly colored Fusarium conidia spores resulting in the possibility of differentiation of such spores at the species level.
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9.
Dumont E Ogra Y Vanhaecke F Suzuki KT Cornelis R 《Analytical and bioanalytical chemistry》2006,384(5):1196-1206
Liquid chromatography (LC) hyphenated with both elemental and molecular mass spectrometry has been used for Se speciation
in Se-enriched garlic. Different species were separated by ion-pair liquid chromatography–inductively coupled plasma mass
spectrometry (LC–ICP–MS) after hot-water extraction. They were identified by on-line reversed-phase liquid chromatography–electrospray
ionization tandem mass spectrometry (RPLC–ESI–MS–MS). Se-methionine and Se-methylselenocysteine were determined by monitoring
their product ions. Another compound, γ-glutamyl-Se-methylselenocysteine, shown to be the most abundant form of Se in the
garlic, was determined without any additional sample pre-treatment after extraction and without the need for a synthesized
standard. Product ions for this dipeptide were detected by LC–ESI–MS–MS for three isotopes of Se—78
Se, 80Se: and 82Se. The method was extended to the species extracted during in-vitro gastrointestinal digestion. Because both Se-methylselenocysteine
and γ-glutamyl-Se-methylselenocysteine have anticarcinogenic properties, their extractability and stability during human digestion
are very important. Garlic was also treated with saliva, to enable detection and analysis of species extracted during mastication.
Detailed information on the extractability of selenium species by both simulated gastric and intestinal fluid are given, and
variation of the distribution of Se among the different species with time is discussed. Although the main species in garlic
is the dipeptide γ-glutamyl-Se-methylselenocysteine, Se-methylselenocysteine is the main compound present in the extracts
after treatment with gastrointestinal fluids. Two more, so far unknown compounds were observed in the chromatogram. The extracted
species and their transformations were analysed by combining LC–ICP–MS and LC–ESI–MS–MS. In both the simulated gastric and
intestinal digests, Se-methionine, Se-methylselenocysteine, and γ-glutamyl-Se-methylselenocysteine could be determined by
LC–ESI–MS–MS by measuring their typical product ions.
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10.
Fanny Kieken Gaud Pinel Jean-Philippe Antignac Fabrice Monteau Anne Christelle Paris Marie-Agnès Popot Yves Bonnaire Bruno Le Bizec 《Analytical and bioanalytical chemistry》2009,394(8):2119-2128
Despite the worldwide existing regulation banning the use of the recombinant equine growth hormone (reGH) as growth promoter,
it is suspected to be used in horseracing to improve performances. Various analytical methods previously developed to screen
for its misuse have encountered some limitations in terms of detection timeframes, in particular during the first days following
reGH administration. A novel strategy involving the characterization of global metabolomic fingerprints in urine samples of
non-treated and reGH-treated horses by liquid chromatography–electrospray–high-resolution mass spectrometry (LC-ESI-HRMS)
is described and assessed in this paper in order to develop a new screening tool for growth hormone abuse in horseracing.
The strategy involves a limited sample preparation of the urine samples and the use of appropriate software for data processing
and analysis. As preliminary work, reproducibility of both sample preparation and mass spectrometry (MS) measurements was
evaluated in order to demonstrate the reliability of the method. Application of the developed protocol on two horses demonstrated
the suitability of the developed strategy and preliminary results showed significant modifications of the metabolome after
treatment with reGH.
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11.
Beate Fuchs Annabell Bischoff Rosmarie Süß Kristin Teuber Martin Schürenberg Detlev Suckau Jürgen Schiller 《Analytical and bioanalytical chemistry》2009,395(8):2479-2487
Phospholipids (PL) are increasingly analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass
spectrometry (MS). As in the case of polar molecules, however, the careful selection of the matrix is crucial for optimum
results. 9-Aminoacridine (9-AA) was recently suggested as the matrix of choice to analyze PL mixtures because of (a) the improved
sensitivity and (b) the reduction of suppression effects compared to other matrices. However, the distinction of phosphatidylcholine
(PC) and phosphatidylethanolamine (PE) in the negative ion mode is obscured as PC is also detectable as –CH3+ ion if 9-AA is used as matrix. This may result in the erroneous assignment of PC as a PE species. Using an organic extract
from hen egg yolk as example it will be shown that the contribution of PC must be taken into consideration if the negative
ion mass spectra are used to evaluate the fatty acyl compositions of PE mixtures. 9-AA can as well be used in hyphenated thin-layer
chromatography (TLC)-MALDI-TOF MS where PC and PE are chromatographically well separated for unequivocal assignments.
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12.
C. R. Dockery A. R. Stefan A. A. Nieuwland S. N. Roberson B. M. Baguley J. E. Hendrix S. L. Morgan 《Analytical and bioanalytical chemistry》2009,394(8):2095-2103
Systematic designed experiments were employed to find the optimum conditions for extraction of direct, reactive, and vat dyes
from cotton fibers prior to forensic characterization. Automated microextractions were coupled with measurements of extraction
efficiencies on a microplate reader UV–visible spectrophotometer to enable rapid screening of extraction efficiency as a function
of solvent composition. Solvent extraction conditions were also developed to be compatible with subsequent forensic characterization
of extracted dyes by capillary electrophoresis with UV–visible diode array detection. The capillary electrophoresis electrolyte
successfully used in this work consists of 5 mM ammonium acetate in 40:60 acetonitrile–water at pH 9.3, with the addition
of sodium dithionite reducing agent to facilitate analysis of vat dyes. The ultimate goal of these research efforts is enhanced
discrimination of trace fiber evidence by analysis of extracted dyes.
Figure Fitted absorbance response surface for extraction of a direct dye, C. I. yellow 58, using a ternary solvent system. 相似文献
13.
Tribalat L Paisse O Dessalces G Grenier-Loustalot MF 《Analytical and bioanalytical chemistry》2006,386(7-8):2161-2168
In the framework of developing analyses for exogenous contaminants in food matrices such as honey, we have compared data obtained
by high-performance liquid chromatography coupled with mass spectrometry (LC–MS) to those provided by high-performance liquid
chromatography and tandem mass spectrometry (LC–MS–MS). Initial results obtained with LC–MS showed that the technique lacked
selectivity, which is why the method was validated by LC–MS–MS. This method involves a solid-phase extraction (SPE) of nitrofuran
metabolites and nitrofuran parent drugs, a derivatization by 2-nitrobenzaldehyde for 17 h, and finally a clean-up by SPE.
The data obtained show that the limits of detection varied between 0.2 and 0.6 μg kg−1 for the metabolites and between 1 and 2 μg kg−1 for nitrofuran parent drugs. The method was applied to different flower honeys. The results showed that nitrofurans (used
as antibiotics) are consistently present in this matrix, the predominant compound being furazolidone.
Figure Working bees 相似文献
14.
Determination of evodiamine and rutecarpine in human serum by liquid chromatography–tandem mass spectrometry 总被引:1,自引:0,他引:1
Evodiamine and rutecarpine are two kinds of indole alkaloids contained in the fruit of Evodiae fructus, which have been shown to exhibit various bioactivities in humans. A liquid chromatography–tandem mass spectrometric method
(LC–MS/MS) was developed for the determination of evodiamine and rutecarpine in human serum. The serum was extracted by solid-phase
extraction (SPE) and analyzed using a C18 column and a mobile phase consisting of methanol–water (85:15) solution containing
5 mmol/L ammonium formate at a flow rate of 0.5 mL/min. The mass spectrometer was operated in positive mode, employing the
extracted ion chromatogram (EIC) for detection and quantitation of evodiamine (m/z 288) and rutecarpine (m/z 304). Good linear relationships between the peak area and the concentration were obtained in the ranges of 5.2–1040 ng/mL
and 10.2–1020 ng/mL, with correlation coefficients (r) of 0.999 and 0.998, for evodiamine and rutecarpine, respectively. The repeatabilities (RSD, n=6) of quantitation for evodiamine and rutecarpine were 2.18–4.00% and 2.99–5.67%, respectively, and the recovery ranged from
90.5% to 98.1%. A comparative study of the different ionization and quantitation modes, including ESI–MS, ESI–MS/MS, APCI–MS
and APCI–MS/MS, was also accomplished. The MS/MS fragmentation mechanism of the base peak ([M+H]+, m/z 304) of evodiamine was investigated in order to identify the analytes in more complicated body fluid samples.
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15.
Corina Flangea Catalin Schiopu Eugen Sisu Alina Serb Michael Przybylski Daniela G. Seidler Alina D. Zamfir 《Analytical and bioanalytical chemistry》2009,395(8):2489-2498
Chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans display variability of sulfation in their constituent
disaccharide repeats during chain elongation. Since a large proportion of the extracellular matrix of the central nervous
system (CNS) is composed of proteoglycans, CS/DS disaccharide degree and profile of sulfation play important roles in the
functional diversity of neurons, brain development, and some of its pathological states. To investigate the sulfation pattern
of CS/DS structures expressed in CNS, we introduced here a novel method based on an advanced system encompassing fully automated
chip nanoelectrospray ionization (nanoESI) in the negative ion mode and high capacity ion trap multistage mass spectrometry
(MS2–MS3) by collision-induced dissociation (CID). This method, introduced here for the first time in glycomics of brain glycosaminoglycans,
was particularly applied to structural investigation of disaccharides obtained by β-elimination and digestion with chondroitin
B and AC I lyase of hybrid CS/DS chains from wild-type mouse brain. Screening in the chip-MS mode of DS disaccharide fraction
resulting after depolymerization with chondroitin B lyase revealed molecular ions assigned to monosulfated disaccharide species
having a composition of 4,5-Δ-[IdoA-GalNAc]. By optimized CID MS2–MS3, fragment ions supporting the localization of sulfate ester group at C4 within GalNAc were produced. Chip ESI MS profiling
of CS disaccharide fraction obtained by depolymerization of the same CS/DS chain using chondroitin AC I lyase indicated the
occurrence of mono- and bisulfated 4,5-Δ-[GlcA-GalNAc]. The site of oversulfation was determined by MS2–MS3, which provided sequence patterns consistent with a rare GlcA-3-sulfate–GalNAc-6-sulfate structural motif.
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16.
Aguinaga N Campillo N Viñas P Hernández-Córdoba M 《Analytical and bioanalytical chemistry》2008,391(4):1419-1424
This paper describes a headspace solid-phase microextraction (HS-SPME) procedure coupled to gas chromatography with mass spectrometric
detection (GC–MS) for the determination of eight PAHs in aquatic species. The influence of various parameters on the PAH extraction
efficiency was carefully examined. At 75 °C and for an extraction time of 60 min, a polydimethylsiloxane–divinylbenzene (PDMS/DVB)
fiber coating was found to be most suitable. Under the optimized conditions, detection limits ranged from 8 to 450 pg g−1, depending on the compound and the sample matrix. The repeatability varied between 7 and 15% (RSD). Accuracy was tested using
the NIST SRM 1974b reference material. The method was successfully applied to different samples, and the studied PAHs were
detected in several of the samples.
Figure Headspace SPME sampling followed by GC–MS facilitates routine monitoring of PAHs in aquatic species 相似文献
17.
Flow field–flow fractionation–inductively coupled plasma optical emission spectrometry (FlFFF–ICP–OES) was applied to achieve
the size-based fractionation of iron in a food suspension in order to gain insights into iron availability. The binding of
iron with phytic and tannic acids, employed as model inhibitors of iron availability in foods, was investigated at pH 2.0
(representing stomach fluid), pH 5.0 (the transition stage in the upper part of the duodenum), and pH 7.0 (the small intestine).
In the presence of phytic acid, iron was found as a free ion or it was associated with molecules smaller than 1 kDa at pH
2.0. Iron associated with molecules larger than 1 kDa when the pH of the mixture was raised to 5.0 and 7.0. In the presence
of tannic acid, iron was again mostly associated with molecules smaller than 1 kDa at pH 2.0. However, at pH 5.0, iron and
tannic acid associated in large molecules (∼25 kDa), while at pH 7.0, most of the iron was associated with macromolecules
larger than 500 kDa. Iron size-based distributions of kale extract and tea infusion containing phytic and tannic acids, respectively,
were also examined at the three pH values, with and without enzymatic digestion. Without enzymatic digestion of the kale extract
and the tea infusion at pH 2.0, most of the iron was released as free ions or associated with molecules smaller than 1 kDa.
At other pH values, most of the iron in the kale extract and the tea infusion was found to bind with ~2 kDa and >500 kDa macromolecules,
respectively. Upon enzymatic gastrointestinal digestion, the iron was not observed to bind to macromolecules >1 kDa but <500 kDa,
due to the enzymatic breakdown of large molecules to smaller ones (<1 kDa).
Figure Flow field–flow fractionation was exploited in order to achieve size-based iron fractionation and thus investigate iron-binding
behavior under gastrointestinal conditions 相似文献
18.
Pyochelin is a siderophore and virulence factor common to Burkholderia cepacia and several Pseudomonas strains. It is isolated from bacterial media as a mixture of two epimers, which readily equilibrate in most solvents. Experiments based on high-performance liquid chromatography/electrospray ionization mass spectrometry are reported here, allowing the investigation of the different Fe(III)-chelating properties of pyochelin diastereomers in solution without the need for labourious isolation. It is demonstrated in this study that only one of the two pyochelin diastereomers is able to chelate Fe(III); no Fe(III) complexes of the other diastereomer could be detected. The Fe(III)–pyochelin complex exhibited a 1:1 metal-to-siderophore ratio and no evidence for other stoichiometries was found.
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19.
Rudolf Tuckermann Ljiljana Puskar Mahta Zavabeti Ryo Sekine Don McNaughton 《Analytical and bioanalytical chemistry》2009,394(5):1433-1441
An experimental apparatus combining Raman spectroscopy with acoustic levitation, Raman acoustic levitation spectroscopy (RALS),
is investigated in the field of physical and chemical analytics. Whereas acoustic levitation enables the contactless handling
of microsized samples, Raman spectroscopy offers the advantage of a noninvasive method without complex sample preparation.
After carrying out some systematic tests to probe the sensitivity of the technique to drop size, shape, and position, RALS
has been successfully applied in monitoring sample dilution and preconcentration, evaporation, crystallization, an acid–base
reaction, and analytes in a surface-enhanced Raman spectroscopy colloidal suspension.
Figure We have systematically investigated the analytical potential of Raman spectroscopy of samples in acoustically levitated drops. 相似文献
20.
A method based on use of functionalized gold nanoparticles on polyethylenimine film has been developed for colorimetric detection of immunoglobulin G (IgG). The immunogold nanoparticles were immobilized on quartz slides by recognition between antibody and antigen, with the antigen chemically adsorbed on the polyethylenimine film. By measurement of the UV–visible spectra of the immobilized immunogold, detection of h-IgG was achieved. The detection limit for h-IgG by use of this method can be as low as 0.01 μg mL−1. This method is quite promising for numerous applications in immunoassay.
Figure 相似文献