Gostaríamos de agradecer ao Ministério da Ciência e Tecnologia de Taiwan (número de concessão: MOST 104-2628-M-009-003-MY4) para o apoio financeiro deste trabalho.

Este protocolo assume que todas as etapas são realizadas de acordo com os regulamentos de segurança laboratoriais relevantes. Algumas das etapas utilizam instrumentos comerciais - nesses casos, as diretrizes do fabricante devem ser seguidas. Ao manusear produtos químicos tóxicos, as diretrizes de MSDS precisam ser seguidas. O equipamento personalizado 4 deve ser operado com cautela; Especialmente, ao manusear gases pressurizados e fiação elétrica ao vivo. 1. Preparação da Solução Padrão <ol><li> Prepare 6,2 x 10 -2 M de solução de estoque de limoneno em etanol através da mistura de 10 uL limoneno com 990 mL de etanol. </li><li> Prepare 10 mL de solução de limoneno 6,2 x 10 -5 M misturando 10 μL de 6,2 x 10 -2 de limoneno, 490 μL de etanol e adicionando água pura ao volume final de 10 mL. Agite bem o balão volumétrico. </li><li> Transfira a solução padrão preparada para um frasco de vidro de 20 ml para o espaço no espaço de cabeça com septuM cap. A solução padrão diluída pode ser usada para testar o sistema. </li></ol> 2. Preparação da amostra real <ol><li> Obtenha suco de limão espremendo frutas com limão fresco (cortadas pela metade) em um espremedor de cozinha. </li><li> Prepare 10 mL de suco de lima diluído misturando 2 mL de suco de lima, 500 μL de etanol e adicionando água pura ao volume final de 10 mL. Agite bem o balão volumétrico. </li><li> Transfira a amostra preparada para um frasco de vidro com visor de 20 mL com tampa de septo. </li></ol> 3. Espalhando a Amostra Real com Solução Padrão <ol><li> Primeira adição de padrão: Preparar 10 ml de amostra enriquecida através da mistura de 2 ml de sumo de lima, 10 mL de 6,2 x 10 solução limoneno -2 M, 490 mL de etanol, e adicionando água pura para o volume final de 10 mL. Agite bem o balão volumétrico. </li><li> Segunda adição padrão: Prepare 10 mL de amostra com ponta misturando 2 mL de suco de lima, 20 μL 6.2 x 10 -2 M limonenE solução, 480 μL de etanol e adicionando água pura ao volume final de 10 mL. Agite bem o balão volumétrico. </li></ol> 4. Configurando o Sistema de Extração Fizzy <ol><li> Coloque o sistema de extração efervescente ( Figura 1 ) 4 ao lado da fonte APCI do espectrômetro de massa tripla quadrupolo. </li><li> Conecte o cilindro de dióxido de carbono à entrada de gás do sistema de extração efervescente. Abra a válvula no regulador de gás. Defina a pressão de saída para 1,5 bar (150 kPa). </li><li> Conecte a saída da câmara de extração à entrada da fonte de iões. </li><li> Conecte o sistema de extração efervescente à fonte de alimentação de 12 V. </li><li> Configure o software de aquisição de dados do espectrômetro de massa triple quadripolar ( Figura 2 ). Operar o instrumento com a fonte APCI, no modo de monitoração de reação múltipla de íons positivos (MRM), com argônio como colisãogás. <ol><li> Execute o software de aquisição de dados. </li><li> Selecione a opção &quot;apenas LCMS8030&quot;. </li><li> Selecione a opção &quot;MS On / Off&quot;. </li><li> Ajuste a temperatura da linha de dessolvatação para 250 ° C e a taxa de fluxo de gás de secagem para 15 L min -1 . Aguarde até que o valor de cada parâmetro do instrumento se torne o mesmo que o valor predefinido. </li><li> Selecione o arquivo do método de aquisição de dados MS. </li><li> Certifique-se de que a tensão de colisão seja -20 V, o íon precursor m / z é 137 e o fragmento ião m / z é 81 e 95 </li><li> Clique no botão &quot;Iniciar a execução única&quot;. </li><li> Digite o nome do arquivo. </li><li> Selecione o caminho do arquivo. </li><li> Mude para a seção 5 (&quot;Executando extração efervescente&quot;). </li><li> Selecione a opção &quot;MS On / Off&quot;. </li><li> Feche a janela do software. </li><li> Marque os itens &quot;Nebulizing Gas Off&quot;, &quot;DL Heater Off&quot;, &quot;Heat Block Off&quot; e &quot;Dry Gas Off&quot;. Clique em &quot;OK &amp;# 34 ;. </li></ol></li></ol> 5. Executando Extração Fizzy <ol><li> Coloque um frasco de amostra no sistema de extração efervescente usando o suporte de parafuso. O sistema de extração é operado a temperatura ambiente (~ 25 ° C). </li><li> Pressione o botão &quot;Iniciar&quot; na tela LCD do sistema de extração efervescente. </li><li> Aguarde enquanto o processo de extração efervescente automatizado é executado ( Figura 3 ). Observe o desenvolvimento de sinais de íons na tela do espectrômetro de massa tripla quadrupolo. NOTA: As seguintes etapas são executadas automaticamente: o espaço de amostra é lavado com dióxido de carbono durante 60 s. A amostra é pressurizada com dióxido de carbono durante 60 s. O motor agitador está ligado. A amostra é despressurizada. São formadas bolhas múltiplas. Na fase posterior, o motor do agitador está ligado para melhorar a borbulhar. </li><li> Retire (desenrosque) o frasco de amostra. </li><li> Limpe o fuso de agitação da amostra com tecido de celulose. </li><li> Lavar a agitaçãoInle com etanol e limpe-o novamente com tecido de celulose. </li><li> O sistema está pronto para análise de outra amostra (repita as etapas 5.1-5.6). </li><li> Desligue a fonte de alimentação. </li><li> Desconecte o tubo de saída de extração efervescente da fonte de íons. </li><li> Feche a válvula do cilindro de gás e desconecte o tubo de gás. </li></ol> 6. Análise de dados <ol><li> Exportação de correntes de íons extraídas para o m / z 81 a partir do software de aquisição de dados do espectrometro de massa quadrupolar triplo para arquivos ASCII ( Figura 4 ). NOTA: A corrente de íons no m / z 95 não é usada nesta demonstração. <ol><li> Execute o software de aquisição de dados. Selecione a opção &quot;Postrun&quot;. </li><li> Selecione a opção &quot;Selecionar projeto (Pasta)&quot; e escolha o arquivo de dados. </li><li> Clique no menu &quot;Arquivo&quot; e selecione &quot;Exportar dados&quot; / &quot;Exportar dados como ASCII&quot;. </li><li> Selecione &amp; #34; Arquivo de saída &quot;e selecione o caminho do arquivo. Selecione&quot; MS Chromatogram (MC) &quot;. </li></ol></li><li> Importe os conjuntos de dados brutos para o software de integração de pico e mestre áreas de pico ( Figura 5 ). Configurações: linha de base linear; Função HVL. <ol><li> Execute o software de integração de picos. </li><li> Selecione a opção &quot;Importar&quot; no menu &quot;Arquivo&quot;. Clique no botão &quot;Sim&quot;. </li><li> Selecione os dados na coluna X e Y. Clique no botão &quot;OK&quot;. Selecione a opção &quot;AutoFit Peaks I Residuals&quot;. </li><li> Ajuste o pico de extração semi-automático. Certifique-se de que a curva ajustada segue os pontos de dados experimentais. Selecione a opção &quot;List Peak Estimates&quot;. Selecione a opção &quot;Editor ASCII&quot;. </li><li> Copie os resultados de montagem para &quot;Clipboard&quot;. </li></ol></li><li> Insira as áreas de pico medidas em uma planilha no software de análise de dados ( Figura 6 ). &lt;Ol&gt; <li> Execute o software de análise de dados. </li><li> Insira os valores de concentração na coluna X e os valores da área de pico na coluna Y. Selecione a opção &quot;Símbolo&quot; / &quot;Dispersão&quot; no menu &quot;Plot&quot;. Selecione a opção &quot;Ajustar&quot; / &quot;Ajustar Linear&quot; no menu &quot;Análise&quot;. </li></ol></li><li> Calcule a concentração de limoneno na amostra real diluída com base na fórmula: <img alt="Equação 1" src="/files/ftp_upload/56008/56008eq1.jpg" /> Onde eu sou a intercepção da função linear, enquanto S é a inclinação. </li><li> Calcule a concentração de limoneno na amostra real original (antes da diluição) com base na fórmula: <img alt="Equação 2" src="/files/ftp_upload/56008/56008eq2.jpg" /> Onde DF é o fator de diluição (aqui, 5). </li></ol>

<ol>
	<li>McCallum, R. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decompression+sickness:+a+review.">Decompression sickness: a review.</a> Brit J Industr Med. 25, 4-21 (1968).</li><li>Pawliszyn, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Comprehensive Sampling and Sample Preparation. , (2012).</li><li>Wang, T., Lenahan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+volatile+halocarbons+in+water+by+purge-closed+loop+gas+chromatography.">Determination of volatile halocarbons in water by purge-closed loop gas chromatography.</a> Bull Environ Contam Toxicol. 32, 429-438 (1984).</li><li>Chang, C. -. H., Urban, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fizzy+extraction+of+volatile+and+semivolatile+compounds+into+the+gas+phase.">Fizzy extraction of volatile and semivolatile compounds into the gas phase.</a> Anal Chem. 88, 8735-8740 (2016).</li><li>Zougagh, M., Valc&#225;rcel, M., R&#237;os, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Supercritical+fluid+extraction:+a+critical+review+of+its+analytical+usefulness.">Supercritical fluid extraction: a critical review of its analytical usefulness.</a> Trends Anal Chem. 23, 399-405 (2004).</li><li>Urban, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Universal+electronics+for+miniature+and+automated+chemical+assays.">Universal electronics for miniature and automated chemical assays.</a> Analyst. 140, 963-975 (2015).</li><li>Urban, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-built+labware+stimulates+creativity.">Self-built labware stimulates creativity.</a> Nature. 532, 313 (2016).</li><li>Chen, H., Venter, A., Cooks, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extractive+electrospray+ionization+for+direct+analysis+of+undiluted+urine,+milk+and+other+complex+mixtures+without+sample+preparation.">Extractive electrospray ionization for direct analysis of undiluted urine, milk and other complex mixtures without sample preparation.</a> Chem Commun. , 2042-2044 (2006).</li><li>Haddad, R., Sparrapan, R., Kotiaho, T., Eberlin, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Easy+ambient+sonic-spray+ionization-membrane+interface+mass+spectrometry+for+direct+analysis+of+solution+constituents.">Easy ambient sonic-spray ionization-membrane interface mass spectrometry for direct analysis of solution constituents.</a> Anal Chem. 80, 898-903 (2008).</li><li>Dixon, R. B., Sampson, J. S., Muddiman, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+multiply+charged+peptides+and+proteins+by+radio+frequency+acoustic+desorption+and+ionization+for+mass+spectrometric+detection.">Generation of multiply charged peptides and proteins by radio frequency acoustic desorption and ionization for mass spectrometric detection.</a> J Am Soc Mass Spectrom. 20, 597-600 (2009).</li><li>Wu, C. -. I., Wang, Y. -. S., Chen, N. G., Wu, C. -. Y., Chen, C. -. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+ionization+of+biomolecules.">Ultrasound ionization of biomolecules.</a> Rapid Commun Mass Spectrom. 24, 2569-2574 (2010).</li><li>Lo, T. -. J., Chen, T. -. Y., Chen, Y. -. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+salt+effects+in+ultrasonication-assisted+spray+ionization+mass+spectrometry.">Study of salt effects in ultrasonication-assisted spray ionization mass spectrometry.</a> J Mass Spectrom. 47, 480-483 (2012).</li><li>Urban, P. L., Chen, Y. -. C., Wang, Y. -. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Time-Resolved Mass Spectrometry: From Concept to Applications. , (2016).</li><li>Peacock, P. M., Zhang, W. -. J., Trimpin, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+ionization+for+mass+spectrometry.">Advances in ionization for mass spectrometry.</a> Anal Chem. 89, 372-388 (2017).</li><li>Hu, J. -. B., Chen, S. -. Y., Wu, J. -. T., Chen, Y. -. C., Urban, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+system+for+extraction+and+instantaneous+analysis+of+millimeter-sized+samples.">Automated system for extraction and instantaneous analysis of millimeter-sized samples.</a> RSC Adv. 4, 10693-10701 (2014).</li><li>Chen, S. -. Y., Urban, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On-line+monitoring+of+Soxhlet+extraction+by+chromatography+and+mass+spectrometry+to+reveal+temporal+extract+profiles.">On-line monitoring of Soxhlet extraction by chromatography and mass spectrometry to reveal temporal extract profiles.</a> Anal Chim Acta. 881, 74-81 (2015).</li><li>Hsieh, K. -. T., Liu, P. -. H., Urban, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+on-line+liquid-liquid+extraction+system+for+temporal+mass+spectrometric+analysis+of+dynamic+samples.">Automated on-line liquid-liquid extraction system for temporal mass spectrometric analysis of dynamic samples.</a> Anal Chim Acta. 894, 35-43 (2015).</li><li>Veach, B. T., Mudalige, T. K., Rye, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RapidFire+mass+spectrometry+with+enhanced+throughput+as+an+alternative+to+liquid&#8722;liquid+salt+assisted+extraction+and+LC/MS+analysis+for+sulfonamides+in+honey.">RapidFire mass spectrometry with enhanced throughput as an alternative to liquid&#8722;liquid salt assisted extraction and LC/MS analysis for sulfonamides in honey.</a> Anal Chem. , (2017).</li><li>Carroll, D. I., Dzidic, I., Stillwell, R. N., Horning, M. G., Horning, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subpicogram+detection+system+for+gas+phase+analysis+based+upon+atmospheric+pressure+ionization+(API)+mass+spectrometry.">Subpicogram detection system for gas phase analysis based upon atmospheric pressure ionization (API) mass spectrometry.</a> Anal Chem. 46, 706-710 (1974).</li><li>Carroll, D. I., Dzidic, I., Stillwell, R. N., Haegele, K. D., Horning, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atmospheric+pressure+ionization+mass+spectrometry.+Corona+discharge+ion+source+for+use+in+a+liquid+chromatograph-mass+spectrometer-computer+analytical+system.">Atmospheric pressure ionization mass spectrometry. Corona discharge ion source for use in a liquid chromatograph-mass spectrometer-computer analytical system.</a> Anal Chem. 47, 2369-2373 (1975).</li><li>Hakim, I. A., McClure, T., Liebler, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+dietary+D-limonene+intake+for+epidemiological+studies.">Assessing dietary D-limonene intake for epidemiological studies.</a> J Food Compos Anal. 13, 329-336 (2000).</li></ol>

Os autores não têm nada a divulgar.

<html> Várias maneiras inteligentes de entregar amostras para um espectrômetro de massa foram desenvolvidas nos estudos realizados nas últimas três décadas ( por exemplo , referências 8 , 9 , 10 , 11 , 12 , 13 , 14 ). Um dos objetivos desses estudos foi simplificar a preparaç...

Vários fenômenos observados na natureza e no cotidiano estão ligados aos equilíbrios da fase gás-líquida. O dióxido de carbono é dissolvido em bebidas suaves e alcoólicas sob pressão elevada. Quando uma garrafa de uma bebida tão efervescente é aberta, a pressão cai e as bolhas de gás correm para a superfície líquida. Neste caso, a efervescência melhora as propriedades organolépticas das bebidas. A liberação de bolhas de gás também é a principal causa da doença de descompressão (&quot;as curvas&quot;) 1 . Devido à descompressão repentina, as bolhas se formam nos corpos dos mergulhadores. As pessoas que sofrem de doenças de descompressão são tratadas em câmaras hiperbáricas. Bolhas de gás têm várias aplicações em química analítica. Notavelmente, os métodos de pulverização dependem da passagem de bolhas de gás através de amostras líquidas para extrair compostos voláteis 2 . Por exemplo, um método chamado &quot;purge-closed loop&quot; é combinado com cromatografia gasosa para permitir uma análise rápida de diVoláteis dissolvidos 3 . Enquanto o pulverizador pode extrair continuamente voláteis ao longo do tempo, não os limita no espaço ou no tempo. As espécies de fase gasosa liberadas precisam ser presas e, em alguns casos, concentradas pela aplicação de um programa de temperatura ou pelo uso de sorventes. Assim, é necessário introduzir novas estratégias de tratamento de amostras on-line, que podem reduzir o número de etapas e, ao mesmo tempo, concentrar analitos voláteis no espaço ou no tempo. Para abordar o desafio de extrair compostos voláteis de amostras líquidas e realizar análises on-line, recentemente introduzimos &quot;extração efervescente&quot; 4 . Esta nova técnica aproveita o fenômeno da efervescência. Resumidamente, um gás transportador (aqui, dióxido de carbono) é primeiro dissolvido na amostra aplicando sobrepressão e agitando a amostra. Então, a câmara de amostra é descompressada abruptamente. A descompressão repentina leva à formação de numerosas bolhas de gás portador<html> No líquido da amostra. Essas bolhas ajudam a liberação de espécies de analitos dissolvidos do líquido para a fase gasosa. Os analitos liberados são imediatamente transferidos para o espectrômetro de massa, produzindo sinais no domínio do tempo. Como a liberação das espécies de analito é limitada a um curto período de tempo (alguns segundos), os sinais temporais têm amplitudes altas e altos índices de sinal para ruído. As pressões envolvidas no processo de extração efervescente são muito baixas (~ 150 kPa) 4 ; Muito inferior à extração de fluido supercrítico 5 ( por exemplo , ≥ 10 MPa). A técnica não requer o uso de itens consumíveis especiais (colunas, cartuchos). Apenas pequenos volumes de solventes são utilizados para diluição e limpeza. O dispositivo de extração pode ser montado por químicos com habilidades técnicas médias usando peças 4 amplamente disponíveis; Por exemplo, módulos eletrônicos de código aberto&quot;&gt; 6 , 7. A extração rápida pode ser acoplada em linha com espectrômetros de massa modernos equipados com interface de ionização química de pressão atmosférica (APCI). Como os extratos de fase gasosa são transferidos para a fonte de íons, a operação de extração efervescente não contamina substancialmente vulneráveis Partes do espectrômetro de massa. O objetivo deste artigo de experiência visualizada é orientar os espectadores sobre como implementar a extração efervescente em uma simples tarefa analítica. Embora o núcleo do sistema de extração efervescente seja conforme descrito em nosso relatório anterior 4 , foram introduzidas várias melhorias para tornar a operação mais direta. Um microcontrolador equipado com um escudo de tela LCD foi incorporado no sistema para exibir os principais parâmetros de extração em tempo real. Todas as funções são programadas nos scripts do microcontrolador e não há mais necessidade de usar um computador externo para cControle o sistema de extração.

<table border="0" cellpadding="0" cellspacing="0" width="963">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Water</td>
			<td style="width:197px;">Fisher</td>
			<td style="width:160px;">W6212</td>
			<td style="width:191px;">Diluent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Ethanol</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:160px;">32221-2.5L</td>
			<td>Diluent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">(R)-(+)-Limonene</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:160px;">183164-100ML</td>
			<td>Standard</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Carbon dioxide</td>
			<td style="width:197px;">ChiaLung</td>
			<td>n/a</td>
			<td>Carrier gas</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Cellulose tissue, Kimwipes Kimtech</td>
			<td style="width:197px;">Kimberly-Clark</td>
			<td>34120</td>
			<td>Used for cleaning</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Triple quadrupole mass spectrometer</td>
			<td style="width:197px;">Shimadzu</td>
			<td style="width:160px;">LCMS-8030</td>
			<td>Detection system</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Atmospheric pressure chemical ionization interface</td>
			<td style="width:197px;">Shimadzu</td>
			<td style="width:160px;">Duis</td>
			<td>Ion source</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">20-mL screw top headspace glass vial with septum cap</td>
			<td style="width:197px;">Thermo Fisher Scientific</td>
			<td style="width:160px;">D-52379</td>
			<td>Sample vial</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">LabSolutions software</td>
			<td style="width:197px;">Shimadzu</td>
			<td>n/a</td>
			<td>version 5.82</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">PeakFit software</td>
			<td style="width:197px;">Systat Software</td>
			<td>n/a</td>
			<td>version 4.12</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">OriginPro software</td>
			<td style="width:197px;">OriginLab</td>
			<td>n/a</td>
			<td>version 8</td>
		</tr>
	</tbody>
</table>

fizzy extraction of volatile organic compounds combined with atmospheric pressure chemical ionization quadrupole mass spectrometry

A análise química de compostos voláteis e semivoláteis dissolvidos em amostras líquidas pode ser desafiadora. Os componentes dissolvidos precisam ser trazidos para a fase gasosa e transferidos de forma eficiente para um sistema de detecção. A extração efervescente aproveita o fenômeno da efervescência. Primeiro, um gás transportador (aqui, dióxido de carbono) é dissolvido na amostra aplicando sobrepressão e agitando a amostra. Em segundo lugar, a câmara de amostra é descomprimida abruptamente. A decomposição leva à formação de inúmeras bolhas de gás portador no líquido da amostra. Essas bolhas auxiliam a liberação da espécie de analito dissolvido do líquido para a fase gasosa. Os analitos libertados são imediatamente transferidos para a interface de ionização química da pressão atmosférica de um espectrômetro de massa triplo quadrupolo. As espécies de analitos ionizáveis ​​originam sinais espectrométricos de massa no domínio do tempo. Como a liberação das espécies de analito ocorre em curtos períodos de tempo (alguns segundosOnds), os sinais temporais têm amplitudes altas e altas relações sinal-ruído. As amplitudes e áreas dos picos temporais podem então ser correlacionadas com as concentrações dos analitos nas amostras líquidas submetidas a extração efervescente, o que permite uma análise quantitativa. As vantagens da extração efervescente incluem: simplicidade, velocidade e uso limitado de produtos químicos (solventes).

No início, o sistema de extração efervescente é testado com uma solução padrão. Posteriormente, a amostra real e a amostra real com o padrão são analisadas. As áreas dos picos temporais de eventos de extração estão correlacionadas com as concentrações dos analitos nas amostras líquidas submetidas a extração efervescente, o que permite a análise quantitativa. Aqui, realizamos adição de duplo padrão para demonstrar capacidades quantitativas da técnica ( <strong class...

Watch this Scientific Journal Video about Fizzy Extraction of Volatile Organic Compounds Combined with Atmospheric Pressure Chemical Ionization Quadrupole Mass Spectrometry at JoVE.com

Fizzy Extraction of Volatile Organic Compounds Combined with Atmospheric Pressure Chemical Ionization Quadrupole Mass Spectrometry

A extração de Fizzy é uma nova técnica de laboratório para análise de compostos voláteis e semivoláteis. Um gás transportador é dissolvido na amostra líquida aplicando sobrepressão e agitando a amostra. A câmara de amostra é então descomprimida. As espécies de analito são liberadas para a fase gasosa devido à efervescência.

Extração efervescente de compostos orgânicos voláteis combinados com a espectrometria de massa de quadrupoolos de ionização química de pressão atmosférica

Chemical analysis of volatile and semivolatile compounds dissolved in liquid samples can be challenging. The dissolved components need to be brought to ...

fizzy-extraction-volatile-organic-compounds-combined-with-atmospheric

Research

Education

JoVE Core

JoVE Journal

Analytical Chemistry

Chemistry

Unit 1

Mass Spectrometry Fragmentation Methods

SCIENTISTS IN ACTION

7.6K visualizações.  National Chiao Tung University.  A extração de Fizzy é uma nova técnica de laboratório para análise de compostos voláteis e semivoláteis. Um gás transportador é dissolvido na amostra líquida aplicando sobrepressão e agitando a amostra. A câmara de amostra é então descomprimida. As espécies de analito são liberadas para a fase gasosa devido à efervescência. 

Vídeo: Fizzy Extraction of Volatile Organic Compounds Combined with Atmospheric Pressure Chemical Ionization Quadrupole Mass Spectrometry

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. Specifically, the sapphire cell enables visual data collection from multiple loadings to solve a set of material balances to precisely determine phase composition. Ternary phase diagrams can then be established to determine the proportion of each component in each phase at a given condition. In principle, any ternary system can be studied although ternary systems (gas-liquid-liquid) are the specific examples discussed herein. For instance, the ternary THF-Water-CO2 system was studied at 25 and 40&#160;&#176;C and is described herein. Of key importance, this technique does not require sampling. Circumventing the possible disturbance of the system equilibrium upon sampling, inherent measurement errors, and technical difficulties of physically sampling under pressure is a significant benefit of this technique. Perhaps as important, the sapphire cell also enables the direct visual observation of the phase behavior. In fact, as the CO2 pressure is increased, the homogeneous THF-Water solution phase splits at about 2 MPa. With this technique, it was possible to easily and clearly observe the cloud point and determine the composition of the newly formed phases as a function of pressure.
The data acquired with the sapphire cell technique can be used for many applications. In our case, we measured swelling and composition for tunable solvents, like gas-expanded liquids, gas-expanded ionic liquids and Organic Aqueous Tunable Systems (OATS)1-4. For the latest system, OATS, the high-pressure sapphire cell enabled the study of (1) phase behavior as a function of pressure and temperature, (2) composition of each phase (gas-liquid-liquid) as a function of pressure and temperature and (3) catalyst partitioning in the two liquid phases as a function of pressure and composition. Finally, the sapphire cell is an especially effective tool to gather accurate and reproducible measurements in a timely fashion.

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus is a unique tool to study, without sampling, phase behavior under a wide range of pressures. Using a cathetometer, very precise volume measurements can be recorded to measure liquid expansion and phase composition. Thus, this synthetic method enables the study of (1) phase equilibria of multi-component mixtures and (2) the partition behavior of catalyst or model compounds as a function of pressure.

Sapphire celular de alta pressão para medições de Equilíbrio de Fases de CO<sub&gt; 2</sub&gt; / Orgânicos / Sistemas de Água

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. ...

Química

Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The analysis of volatile and oxidation sensitive compounds by mass spectrometry is not easily achieved, as all state-of-the-art mass spectrometric methods require at least one sample preparation step, e.g., dissolution and dilution of the analyte (electrospray ionization), co-crystallization of the analyte with a matrix compound (matrix-assisted laser desorption/ionization), or transfer of the prepared samples into the ionization source of the mass spectrometer, to be conducted under atmospheric conditions. Here, the use of a sample inlet system is described which enables the analysis of volatile metal organyls, silanes, and phosphanes using a sector field mass spectrometer equipped with an electron impact ionization source. All sample preparation steps and the sample introduction into the ion source of the mass spectrometer take place either under air-free conditions or under vacuum, enabling the analysis of compounds highly susceptible to oxidation. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes, which have to be handled using inert conditions, such as the Schlenk technique. The principle of operation is presented in this video.

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes which have to be handled using inert conditions, such as the Schlenk technique.

Análise de compostos sensíveis voláteis e oxidação usando um sistema de frio e de entrada Electron Impact Espectrometria de Massa

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The ...

A Study of the Complexation of Mercury(II) with Dicysteinyl Tetrapeptides by Electrospray Ionization Mass Spectrometry

In this study we evaluated a method for the characterization of complexes, formed in different relative ratios of mercury(II) to dicysteinyl tetrapeptide, by electrospray ionization orbitrap mass spectrometry. This strategy is based on previous successful characterization of mercury-dicysteinyl complexes involving tripeptides by utilizing mass spectrometry among other techniques. Mercury(II) chloride and a dicysteinyl tetrapeptide were incubated in a degassed buffered medium at varying stoichiometric ratios. The complexes formed were subsequently analyzed on an electrospray mass spectrometer consisting of a hybrid linear ion- and orbi- trap mass analyzer. The electrospray ionization mass spectrometry (ESI-MS) spectra were acquired in the positive mode and the observed peaks were then analyzed for distinct mercury isotopic distribution patterns and associated monoisotopic peak. This work demonstrates that an accurate stoichiometry of mercury and peptide in the complexes formed under specified electrospray ionization conditions can be determined by using high resolution ESI MS based on distinct mercury isotopic distribution patterns.

A Study of the Complexation of MercuryII with Dicysteinyl Tetrapeptides by Electrospray Ionization Mass Spectrometry

The characterization of complexes formed in different relative ratios of mercury(II) to dicysteinyl tetrapeptides by electrospray ionization orbitrap mass spectrometry is presented.

Um estudo da complexação de mercúrio (II) com Dicysteinyl tetrapéptidos por Espectrometria de Massa de Ionização por Electrospray

In this study we evaluated a method for the characterization of complexes, formed in different relative ratios of mercury(II) to dicysteinyl tetrapeptide, ...

Visualization of Ambient Mass Spectrometry with the Use of Schlieren Photography

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass spectrometer, it is necessary to characterize and understand the physical principles of the source. Most commercial ambient ionization sources utilize jets of nitrogen, helium, or atmospheric air to facilitate the ionization of the analyte. As a consequence, schlieren photography can be used to visualize the gas streams by exploiting the differences in refractive index between the streams and ambient air for visualization in real time. The basic setup requires a camera, mirror, flashlight, and razor blade. When properly configured, a real time image of the source is observed by watching its reflection. This allows for insight into the mechanism of action in the source, and pathways to its optimization can be elucidated. Light is shed on an otherwise invisible situation.

This paper presents a protocol for the visualization of gaseous streams of an ambient ionization source using schlieren photography and mass spectrometry.

Visualização de ambiente Espectrometria de Massa com o uso da fotografia Schlieren

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass ...

Real-time Breath Analysis by Using Secondary Nanoelectrospray Ionization Coupled to High Resolution Mass Spectrometry

Exhaled volatile organic compounds (VOCs) have aroused considerable interest, since they can serve as biomarkers for disease diagnosis and environmental exposure in a non-invasive manner. In this work, we present a protocol to characterize the exhaled VOCs in real time by using secondary nanoelectrospray ionization coupled to high resolution mass spectrometry (Sec-nanoESI-HRMS). The homemade Sec-nanoESI source was readily set up based on a commercial nanoESI source. Hundreds of peaks were observed in the background-subtracted mass spectra of exhaled breath, and the mass accuracy values are -4.0-13.5 ppm and -20.3-1.3 ppm in the positive and negative ion detection modes, respectively. The peaks were assigned with accurate elemental composition according to the accurate mass and isotopic pattern. Less than 30 s is used for one exhalation measurement, and it takes approximately 7 min for six replicated measurements.

A protocol for characterizing chemical composition of exhaled breath in real time by using secondary nanoelectrospray ionization coupled to high resolution mass spectrometry is demonstrated.

Análise de respiração em tempo real usando o Nanoelectrospray secundário ionização acoplada a espectrometria de massa de alta resolução

Exhaled volatile organic compounds (VOCs) have aroused considerable interest, since they can serve as biomarkers for disease diagnosis and environmental ...

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry

There are many techniques that can be employed in the characterization of synthetic homopolymers, but few provide as useful of information for end group analysis as matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). This tutorial demonstrates methods for optimization of the sample preparation, spectral acquisition, and data analysis of synthetic polymers using MALDI-TOF MS. Critical parameters during sample preparation include the selection of the matrix, identification of an appropriate cationization salt, and tuning the relative proportions of the matrix, cation, and analyte. The acquisition parameters, such as mode (linear or reflector), polarization (positive or negative), acceleration voltage, and delay time, are also important. Given some knowledge of the chemistry involved to synthesize the polymer and optimizing both the data acquisition parameters and the sample preparation conditions, spectra should be obtained with sufficient resolution and mass accuracy to enable the unambiguous determination of the end groups of most homopolymers (masses below 10,000) in addition to the repeat unit mass and the overall molecular weight distribution. Though demonstrated on a limited set of polymers, these general techniques are applicable to a much wider range of synthetic polymers for determining mass distributions, though end group determination is only possible for homopolymers with narrow dispersity.

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight MALDI-TOF Mass Spectrometry

A protocol for the matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) characterization of synthetic polymers is described including the optimization of sample preparation, spectral acquisition, and data analysis.

Caracterização de Polímeros Sintéticos via Espectrometria de Massa por Ionização a Laser com Matriz Assistida por Tempo de Voo (MALDI-TOF)

There are many techniques that can be employed in the characterization of synthetic homopolymers, but few provide as useful of information for end group ...

Analysis of Complex Molecules and Their Reactions on Surfaces by Means of Cluster-Induced Desorption/Ionization Mass Spectrometry

Desorption/Ionization Induced by Neutral SO2 Clusters (DINeC) is employed as a very soft and efficient desorption/ionization technique for mass spectrometry (MS) of complex molecules and their reactions on surfaces. DINeC is based on a beam of SO2 clusters impacting on the sample surface at low cluster energy. During cluster-surface impact, some of the surface molecules are desorbed and ionized via dissolvation in the impacting cluster; as a result of this dissolvation-mediated desorption mechanism, low cluster energy is sufficient and the desorption process is extremely soft. Both surface adsorbates and molecules of which the surface is composed of can be analyzed. Clear and fragmentation-free spectra from complex molecules such as peptides and proteins are obtained. DINeC does not require any special sample preparation, in particular no matrix has to be applied. The method yields quantitative information on the composition of the samples; molecules at a surface coverage as low as 0.1 % of a monolayer can be detected. Surface reactions such as H/D exchange or thermal decomposition can be observed in real-time and the kinetics of the reactions can be deduced. Using a pulsed nozzle for cluster beam generation, DINeC can be efficiently combined with ion trap mass spectrometry. The matrix-free and soft nature of the DINeC process in combination with the MSn capabilities of the ion trap allows for very detailed and unambiguous analysis of the chemical composition of complex organic samples and organic adsorbates on surfaces.

Neutral SO2 clusters of low kinetic energy (&#60; 0.8 eV/constituent) are used to desorb complex surface molecules such as peptides or lipids for further analysis by means of mass spectrometry using an ion trap mass spectrometer. No special sample preparation is required, and real-time observation of reactions is possible.

Análise de Moléculas Complexas e Suas Reações em Superfícies por meio da espectrometria de desormetria/desonização induzida por cluster

Desorption/Ionization Induced by Neutral SO2 Clusters (DINeC) is employed as a very soft and efficient desorption/ionization technique for mass ...

Mass Spectrometry-Guided Genome Mining as a Tool to Uncover Novel Natural Products

The chemical space covered by natural products is immense and widely unrecognized. Therefore, convenient methodologies to perform wide-ranging evaluation of their functions in nature and potential human benefits (e.g., for drug discovery applications) are desired. This protocol describes the combination of genome mining (GM) and molecular networking (MN), two contemporary approaches that match gene cluster-encoded annotations in whole genome sequencing with chemical structure signatures from crude metabolic extracts. This is the first step towards the discovery of new natural entities. These concepts, when applied together, are defined here as MS-guided genome mining. In this method, the main components are previously designated (using MN), and structurally related new candidates are associated with genome sequence annotations (using GM). Combining GM and MN is a profitable strategy to target new molecule backbones or harvest metabolic profiles in order to identify analogues from already known compounds.

A mass spectrometry-guided genome mining protocol is established and described here. It is based on genome sequence information and LC-MS/MS analysis and aims to facilitate identification of molecules from complex microbial and plant extracts.

Mineração de genoma guiada por espectrometria em massa como ferramenta para descobrir novos produtos naturais

The chemical space covered by natural products is immense and widely unrecognized. Therefore, convenient methodologies to perform wide-ranging evaluation ...

Gas Chromatography-Mass Spectrometry Paired with Total Vaporization Solid-Phase Microextraction as a Forensic Tool

Gas Chromatography &#8211; Mass Spectrometry (GC-MS) is a frequently used technique for the analysis of numerous analytes of forensic interest, including controlled substances, ignitable liquids, and explosives. GC-MS can be coupled with Solid-Phase Microextraction (SPME), in which a fiber with a sorptive coating is placed into the headspace above a sample or immersed in a liquid sample. Analytes are sorbed onto the fiber which is then placed inside the heated GC inlet for desorption. Total Vaporization Solid-Phase Microextraction (TV-SPME) utilizes the same technique as immersion SPME but immerses the fiber into a completely vaporized sample extract. This complete vaporization results in a partition between only the vapor phase and the SPME fiber without interference from a liquid phase or any insoluble materials. Depending upon the boiling point of the solvent used, TV-SPME allows for large sample volumes (e.g., up to hundreds of microliters). On-fiber derivatization may also be performed using TV-SPME. TV-SPME has been used to analyze drugs and their metabolites in hair, urine, and saliva. This simple technique has also been applied to street drugs, lipids, fuel samples, post-blast explosive residues, and pollutants in water. This paper highlights the use of TV-SPME to identify illegal adulterants in very small samples (microliter quantities) of alcoholic beverages. Both gamma-hydroxybutyrate (GHB) and gamma-butyrolactone (GBL) were identified at levels that would be found in spiked drinks. Derivatization by a trimethylsilyl agent allowed for conversion of the aqueous matrix and GHB into their TMS derivatives. Overall, TV-SPME is quick, easy, and requires no sample preparation aside from placing the sample into a headspace vial.

Total Vaporization Solid Phase Microextraction (TV-SPME) completely vaporizes a liquid sample whilst analytes are sorbed onto a SPME fiber. This allows for partitioning of the analyte between only the solvent vapor and the SPME fiber coating.

Espectrometria de massa de cromatografia a gás emparelhada com microextração de fase sólida de vaporização total como ferramenta forense

Gas Chromatography &#8211; Mass Spectrometry (GC-MS) is a frequently used technique for the analysis of numerous analytes of forensic interest, including ...

Organic Solvent-Based Protein Precipitation for Robust Proteome Purification Ahead of Mass Spectrometry

While multiple advances in mass spectrometry (MS) instruments have improved qualitative and quantitative proteome analysis, more reliable front-end approaches to isolate, enrich, and process proteins ahead of MS are critical for successful proteome characterization. Low, inconsistent protein recovery and residual impurities such as surfactants are detrimental to MS analysis. Protein precipitation is often considered unreliable, time-consuming, and technically challenging to perform compared to other sample preparation strategies. These concerns are overcome by employing optimal protein precipitation protocols. For acetone precipitation, the combination of specific salts, temperature control, solvent composition, and precipitation time is critical, while the efficiency of chloroform/methanol/water precipitation depends on proper pipetting and vial manipulation. Alternatively, these precipitation protocols are streamlined and semi-automated within a disposable spin cartridge. The expected outcomes of solvent-based protein precipitation in the conventional format and using a disposable, two-stage filtration and extraction cartridge are illustrated in this work. This includes the detailed characterization of proteomic mixtures by bottom-up LC-MS/MS analysis. The superior performance of SDS-based workflows is also demonstrated relative to non-contaminated protein.

The present protocol describes solvent-based protein precipitation under controlled conditions for robust and rapid recovery and purification of proteome samples prior to mass spectrometry.

Precipitação de proteína orgânica baseada em solventes para purificação robusta de proteome antes da espectrometria de massa

While multiple advances in mass spectrometry (MS) instruments have improved qualitative and quantitative proteome analysis, more reliable front-end ...