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2.
Anal Chem ; 86(9): 4316-26, 2014 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-24678766

RESUMO

A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare agents (CWAs) comprising gaseous (two blood agents, three choking agents), volatile (six nerve gases and one precursor agent, five blister agents), and nonvolatile (three lachrymators, three vomiting agents) agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MS(n)). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS(3) product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous agents were detected by MS or MS(2) in negative ion mode. The limits of detection for a 1 s measurement were typically at or below the microgram per cubic meter level except for chloropicrin (submilligram per cubic meter). Matrix effects by gasoline vapor resulted in minimal false-positive signals for all the CWAs and some signal suppression in the case of mustard gas. The moisture level did influence the measurement of the CWAs.


Assuntos
Poluentes Atmosféricos/análise , Substâncias para a Guerra Química/análise , Espectrometria de Massas em Tandem/métodos , Pressão Atmosférica , Limite de Detecção
3.
ACS Appl Mater Interfaces ; 5(10): 4173-80, 2013 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-23668627

RESUMO

We have detected biological toxins using localized surface plasmon resonance (LSPR) and synthetic glycosyl ceramides (ß-lactoside, globosyl trisaccharide (Gb3), or GM1 pentasaccharide) attached to gold (Au) nanoparticles. The particle diameters ranged from 5-100 nm. The detection sensitivity for three toxins (ricin, Shiga toxin, and cholera toxin) was found to depend not only on the attached glycoside but also on the diameter of the Au nanoparticles. For the detection of ricin, the 20-nm ß-lactoside-coated Au nanoparticle exhibited the highest LSPR response, whereas 40-nm Gb3- and GM1-coated Au nanoparticles gave the best results for Shiga toxin and cholera toxin, respectively. In addition, a blocking process on the nanoparticle surface greatly improved the detection sensitivity for cholera toxin. The LSPR system enabled us to detect ricin at 30 ng/mL, Shiga toxin at 10 ng/mL, and the cholera toxin at 20 ng/mL.


Assuntos
Oligossacarídeos/química , Ressonância de Plasmônio de Superfície/métodos , Toxinas Biológicas/análise , Membrana Celular/química , Endocitose , Dispositivos Lab-On-A-Chip
4.
Anal Chem ; 85(5): 2659-66, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23339735

RESUMO

A new method for sensitively and selectively detecting chemical warfare agents (CWAs) in air was developed using counter-flow introduction atmospheric pressure chemical ionization mass spectrometry (MS). Four volatile and highly toxic CWAs were examined, including the nerve gases sarin and tabun, and the blister agents mustard gas (HD) and Lewisite 1 (L1). Soft ionization was performed using corona discharge to form reactant ions, and the ions were sent in the direction opposite to the airflow by an electric field to eliminate the interfering neutral molecules such as ozone and nitrogen oxide. This resulted in efficient ionization of the target CWAs, especially in the negative ionization mode. Quadrupole MS (QMS) and ion trap tandem MS (ITMS) instruments were developed and investigated, which were movable on the building floor. For sarin, tabun, and HD, the protonated molecular ions and their fragment ions were observed in the positive ion mode. For L1, the chloride adduct ions of L1 hydrolysis products were observed in negative ion mode. The limit of detection (LOD) values in real-time or for a 1 s measurement monitoring the characteristic ions were between 1 and 8 µg/m(3) in QMS instrument. Collision-induced fragmentation patterns for the CWAs were observed in an ITMS instrument, and optimized combinations of the parent and daughter ion pairs were selected to achieve real-time detection with LOD values of around 1 µg/m(3). This is a first demonstration of sensitive and specific real-time detection of both positively and negatively ionizable CWAs by MS instruments used for field monitoring.

5.
ACS Appl Mater Interfaces ; 4(2): 832-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22214533

RESUMO

Two types of biotin-tagged glycopolymers carrying lactose or glucose in clusters along the polyacrylamide backbone were prepared and subjected to decontamination analyses with the plant toxin ricin. A buffer solution containing the toxin was treated with one glycopolymer followed by streptavidin-magnetic particles. Supernatant solutions were analyzed with surface plasmon resonance and capillary electrophoresis, and revealed that the lactose glycopolymer "captured" this toxin more effectively than the glucose polymer. Free toxin was not detectable in the supernatant after treatment with the glycopolymer and magnetic particles; >99% decontamination was achieved for this potentially fatal biological toxin.

6.
Carbohydr Res ; 346(13): 1820-6, 2011 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-21784417

RESUMO

A series of sugar-modified porous silica monoliths with different sugar ligands (ß-lactoside, ß-N-acetyllactosaminide, ß-d-galactoside, ß-d-N-acetylgalactosaminide and ß-d-glucoside) and linkers were prepared and evaluated using plant toxins and lectins including ricin and a Ricinus communis agglutinin (RCA(120)). Among these sugar monoliths, a lactose monolith carrying a triethylene glycol spacer adsorbed ricin and RCA(120) with the highest efficiency. The monolith showed no binding with albumin, globulin, and lectins from Jack beans, Osage orange, Amur maackia and wheat germ. All these data support the utility of the lactose-modified monolith as a tool for adsorption and decontamination of plant toxins.


Assuntos
Descontaminação/métodos , Lactose/química , Lectinas de Plantas/química , Toxinas Biológicas/química , Adsorção , Glicosídeos/química , Lectinas de Plantas/isolamento & purificação , Ricina/química , Toxinas Biológicas/isolamento & purificação
7.
ACS Appl Mater Interfaces ; 2(4): 1081-5, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20369893

RESUMO

Developing a technology for detecting and decontaminating biological toxins is needed. Ricin from Ricinus communis is a highly poisonous toxin; it was formerly used for an assassination in London and in postal attacks in the United States. Ricin is readily available from castor beans and could be used as a biological agent. We propose using glycotechnology against the illegal use of ricin. Lactose (a natural ligand of this toxin) was incorporated into polyacrylamide-based glycopolymers at variable sugar densities (18-100%) and evaluated with surface plasmon resonance (SPR) spectroscopy and the real agent, ricin. Glycopolymers (18-65% lactose densities) effectively interfered with the toxin-lactoside adhesion event (>99% efficiency within 20 min). This supported the notion of using the mammary sugar lactose against a deadly biological toxin.


Assuntos
Lactose/química , Ricina/química , Sítios de Ligação/genética , Técnicas Biossensoriais , Bioterrorismo , Semente de Rícino/metabolismo , Endocitose , Glicosídeos/química , Ligantes , Modelos Químicos , Polímeros/química , Ressonância de Plasmônio de Superfície , Fatores de Tempo , Toxinas Biológicas/química
8.
Biosens Bioelectron ; 24(4): 929-33, 2008 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18799304

RESUMO

Because of the illegal use of highly toxic ricin from the castor-oil plant, Ricinus communis, in bioterrorism and suspected white powder cases, anti-terrorism measures for the toxin are urgently required. Here we demonstrate a facile and sensitive detection method using synthetic analogues of beta-lactosyl- and beta-d-galactosyl ceramides as the ligands based on the fact that ricin binds cell-surface oligosaccharides. Sugar-probes having lipoic acids as anchor functions were synthesized via either a chemical or chemoenzymatic way and were immobilized on the sensor chips by a self-assembled monolayer technique. Surface plasmon resonance (SPR) analysis using these carbohydrate probes allowed us to detect the toxin in a highly sensitive and facile manner (10 pg/mL, 5 min), being the best benchmark as a method for detecting the toxin. In addition, a visual monitoring method was developed, in which sugar-coated Au nanoparticles were utilized for discriminating ricin from other proteins in a facile manner, taking 10-30 min for judgment.


Assuntos
Técnicas Biossensoriais/instrumentação , Carboidratos/química , Nanopartículas/química , Ricina/análise , Ressonância de Plasmônio de Superfície/instrumentação , Técnicas Biossensoriais/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Ouro/química , Nanopartículas/ultraestrutura , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
J Chromatogr A ; 1122(1-2): 242-8, 2006 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-16707130

RESUMO

A method for determining N-ethyldiethanolamine (EDEA), N-methyldiethanolamine (MDEA) and triethanolamine (TEA), hydrolysis products of nitrogen mustards, in water, urine and blood samples using gas chromatography-mass spectrometry (GC-MS) after derivatization by tert-butyldimethylsilylation (TBDMS) is described. The sample solution was evaporated to dryness, and reacted with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) at 60 degrees C for 1h. The TBDMS derivatives were separated on a DB-5 column and detected by electron-ionization MS. The quantitation of EDEA, MDEA and TEA was performed by measuring the respective peak areas on the extracted ion chromatograms of m/z 216, m/z 202 and m/z 346, respectively, using nonadecane (C19), the peak area of which was measured at m/z 268, as an internal standard. When the water sample was initially analyzed, considerable loss of EDEA, MDEA and TEA occurred by evaporation. The addition of hydrochloric acid (HCl) to the water sample (final 1 mM), however, permitted quantitative recoveries to be achieved (88%, 88% and 79% for EDEA-(TBDMS)2, MDEA-(TBDMS)2 and TEA-(TBDMS)3, respectively). The limits of detections (LODs, scan mode, S/N = 3) were 2.5, 2.5 and 10 ng/ml for EDEA, MDEA and TEA, respectively. Ethanolamines could be also determined in urine samples (volume 0.1 ml), with reasonable recoveries of 72-100% by the addition of HCl (final 1 mM). For the analysis of serum samples, the sample was precipitated by the addition of perchloric acid (final 3.2%), and the resulting supernatant was neutralized with potassium carbonate, and then acidified by the addition of HCl. The recovery of TBDMS derivatives of ethanolamines was found to rather low (7-31%).


Assuntos
Etanolaminas/análise , Fluoracetatos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Mecloretamina/química , Compostos de Organossilício/química , Acetamidas , Calibragem , Etanolaminas/sangue , Etanolaminas/urina , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Humanos , Hidrólise , Mecloretamina/análise , Reprodutibilidade dos Testes , Ácido Trifluoracético/química
10.
J Chromatogr A ; 1061(2): 235-41, 2004 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-15641367

RESUMO

A method for determining thiodiglycol (TDG), a mustard gas hydrolysis product in water, serum and urine samples using gas chromatography-mass spectrometry (GC-MS) after tert-butyldimethylsilylation (TBDMS) is described. Quantitation of TDG was performed by measuring the respective peak area on the extracted ion chromatogram of m/z 293, using an internal standard, the TDG homologue, thiodipropanol, peak area of which was measured as m/z 321. The presence of salts in the sample solution not only suppressed the loss of TDG by vaporization during the evaporation of water, but also facilitated the rate of production of di-silylated derivative, bis(tert-butyldimethylsilyoxylethyl)sulfide (TDG-(TBDMS)2). Under the pretreatment conditions used, in which 0.5 ml of water sample supplemented with 100 microM potassium chloride was evaporated to dryness under reduced pressure, followed by reaction with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide at 60 degrees C for 1 h, TDG-(TBDMS)2 was reproducibly detected with about a 55% recovery and a limit of detection (LOD, scan mode, S/N = 3) of 5.4 ng/ml. TDG was also determined by GC-MS from a 0.5 ml serum sample (after perchloric acid deproteinization) and from a 0.1 ml urine sample, after TBDMS derivatization. The LOD was determined to be 7.0 and 110 ng/ml for serum and urine, respectively.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Gás de Mostarda/química , Silanos/química , Compostos de Sulfidrila/análise , Hidrólise , Sensibilidade e Especificidade , Compostos de Sulfidrila/sangue , Compostos de Sulfidrila/urina
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