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Neste estudo, avaliou-se o potencial de quantificação UHPLC-MS, Cromatografia Líquida de Ultra Desempenho acoplada a Espectrometria de Massa, através da análise de três espécies químicas: ácido succínico, colina e tetraciclina. O objetivo foi identificar como diferentes parâ metros do método impactam a análise das diferentes espécies químicas e, consequentemente, a sensibilidade e robustez do método.
Os resultados demonstraram que a constituição da fase móvel influencia de forma significativa a ionização dos analitos na fonte ESI, Ionização por Eletrospray, e, por conseguinte, a sensibilidade do método. A redução da concentração de Ácido A, associada a um aumento do pH da fase móvel de 2,3 para 3,3, provocou um incremento de 50 vezes na resposta do ácido succínico. Este resultado demonstra que compostos com tendência para desprotonar reque rem fases mais alcalinas, enquanto espécies com carga positiva ou tendência para protonar, como a colina e a tetraciclina, atingem maior sensibilidade com fases móveis mais ácidas.
O UHPLC-MS permitiu alcançar limites de quantificação (LoQ) reduzidos: 1,69 ppb para a colina, 675 ppb para o ácido succínico e 78 ppb para a tetraciclina. Comparativamente com métodos da Literatura com deteção por UV, dispendiosos para analise compostos não cromóforos, como a colina e ácido succínico, os limites obtidos foram até 170 vezes inferiores no caso do ácido succínico e 6 vezes inferiores no caso da tetraciclina. O limite de deteção (LoD) da colina foi de 0,5 ppb, inferior aos descritos na literatura.
A robustez do método revelou-se fortemente dependente do tamponamento da fase móvel, um parâmetro com impacto particularmente relevante nesta técnica. A fase ajustada, contendo 0,5 M de Sal C, 1,1 mM de Ácido C e 0,9 mM de Ácido A, permitiu obter valores máximos de RSD% de 10% e 0,9%, cumprindo os requisitos descritos na norma ICH Q2(R2) para a análise do ácido succínico.
Este estudo evidencia a importância da otimização da fase móvel e do seu tampona mento para garantir sensibilidade e precisão por UHPLC-MS, permitindo estabelecer diretrizes fundamentais para o desenvolvimento de métodos aplicáveis a diferentes espécies químicas.
This study investigated the quantification potential of UHPLC-MS, Ultra-High Performance Liquid Chromatography coupled with Mass Spectrometry, through the analysis of three chemical species: succinic acid, choline, and tetracycline. The objective was to determine how different method parameters affect the analysis of these chemical species and, consequently, the method’s sensitivity and robustness. The results demonstrated that the composition of the mobile phase significantly influences the ionization of analytes in the ESI source (Electrospray Ionization), and thus the sensitivity of the method. A reduction in the concentration of Acid A, corresponding to an increase in the mobile phase pH from 2.3 to 3.3, resulted in a fifty-fold increase in the response of succinic acid. This finding indicates that compounds prone to deprotonation require more alkaline phases, whereas positively charged species or those prone to protonation, such as choline and tetracycline, achieve higher sensitivity with more acidic mobile phases. UHPLC-MS enabled the achievement of low limits of quantification (LoQ): 1.69 ppb for choline, 675 ppb for succinic acid, and 78 ppb for tetracycline. Compared to literature methods using UV detection, which are costly for the analysis of non-chromophoric compounds like choline and succinic acid, the limits obtained were up to 170 times lower for succinic acid and six times lower for tetracycline. The limit of detection (LoD) for choline was 0.5 ppb, lower than those reported in the literature. Method robustness proved highly dependent on mobile phase buffering, a parameter of particular relevance in this technique. The optimized mobile phase, containing 0.5 M Salt C, 1.1 mM Acid C, and 0.9 mM Acid A, allowed maximum relative standard deviation (RSD%) values of 10% and 0.9%, respectively, meeting the requirements of the ICH Q2(R2) guideline for succinic acid analysis. This study highlights the importance of optimizing the mobile phase composition and buffering to ensure sensitivity and precision by UHPLC-MS, providing essential guidelines for the development of methods applicable to diverse chemical species.
This study investigated the quantification potential of UHPLC-MS, Ultra-High Performance Liquid Chromatography coupled with Mass Spectrometry, through the analysis of three chemical species: succinic acid, choline, and tetracycline. The objective was to determine how different method parameters affect the analysis of these chemical species and, consequently, the method’s sensitivity and robustness. The results demonstrated that the composition of the mobile phase significantly influences the ionization of analytes in the ESI source (Electrospray Ionization), and thus the sensitivity of the method. A reduction in the concentration of Acid A, corresponding to an increase in the mobile phase pH from 2.3 to 3.3, resulted in a fifty-fold increase in the response of succinic acid. This finding indicates that compounds prone to deprotonation require more alkaline phases, whereas positively charged species or those prone to protonation, such as choline and tetracycline, achieve higher sensitivity with more acidic mobile phases. UHPLC-MS enabled the achievement of low limits of quantification (LoQ): 1.69 ppb for choline, 675 ppb for succinic acid, and 78 ppb for tetracycline. Compared to literature methods using UV detection, which are costly for the analysis of non-chromophoric compounds like choline and succinic acid, the limits obtained were up to 170 times lower for succinic acid and six times lower for tetracycline. The limit of detection (LoD) for choline was 0.5 ppb, lower than those reported in the literature. Method robustness proved highly dependent on mobile phase buffering, a parameter of particular relevance in this technique. The optimized mobile phase, containing 0.5 M Salt C, 1.1 mM Acid C, and 0.9 mM Acid A, allowed maximum relative standard deviation (RSD%) values of 10% and 0.9%, respectively, meeting the requirements of the ICH Q2(R2) guideline for succinic acid analysis. This study highlights the importance of optimizing the mobile phase composition and buffering to ensure sensitivity and precision by UHPLC-MS, providing essential guidelines for the development of methods applicable to diverse chemical species.
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Espetrometria de massa fase móvel ionização ESI sensibilidade tamponamento
