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Incorrect determination of lower limit of quantification (LLOQ) of analytical methods
Determinación incorrecta del límite inferior de cuantificación (LIDC) de los métodos analíticos
Determinação incorreta do limite inferior de quantificação (LIDQ) dos métodos analíticos
DOI:
https://doi.org/10.15446/rcciquifa.v54n1.117696Palabras clave:
Analytical method, FDA, LLOQ, LOD, LOQ (en)Método analítico, Administración de Alimentos y Medicamentos, LIDC, LDD, LDC (es)
Método analítico, FDA, LIDQ, LDD, LDQ (pt)
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Generally, a new analytical method for publication in a scientific journal should report some parameters to claim that the technique has acceptable validity and has acceptable sensitivity in contrast to other methods. The most commonly reported parameters are limit of detection (LOD), limit of quantification (LOQ), and lower limit of quantification (LLOQ). Recently, LLOQ was selected by researchers to show the lowest concentration level that can be determined. Based on the FDA’s guidelines, some criteria should be considered in reporting LLOQ. In this study, previously reported analytical methods were investigated to check if they considered FDA’s criteria (relative standard deviation of LLOQ, signal-to-noise, and back-calculated error for LLOQ). Besides the FDA guideline’s criteria, the established criteria based on the calibration curve equation and the linear range were calculated to confirm the validity of the reported LLOQ. Analysis of data indicates that the most LLOQ values are not defined based on FDA guidelines, and they do not show the correct sensitivity value of the reported analytical method.
Objetivos: Generalmente, un nuevo método analítico para publicación en una revista científica debe reportar algunos parámetros para afirmar que la técnica tiene una validez y sensibilidad aceptables en contraste con otros métodos. Los parámetros informados con mayor frecuencia son el límite de detección (LDD), el límite de cuantificación (LDC) y el límite inferior de cuantificación (LIDC). Recientemente, los investigadores seleccionaron LIDC para mostrar el nivel de concentración más bajo que se puede determinar. Según las pautas de la FDA, se deben tener en cuenta algunos criterios al informar el LIDC. Métodos: En este estudio, se investigaron los métodos analíticos informados previamente para verificar si consideraban los criterios de la FDA (desviación estándar relativa del LIDC, relación señal-ruido y error retrocalculado para el LIDC). Además de los criterios de las directrices de la FDA, se calcularon los criterios establecidos basados en la ecuación de la curva de calibración y el rango lineal para confirmar la validez del LIDC informado. Resultados: El análisis de datos indica que la mayoría de los valores LIDC no están definidos según las pautas de la FDA y no muestran el valor de sensibilidad correcto del método analítico informado. Conclusiones: Considerando que todos los criterios recomendados para LIDC son necesarios para la correcta determinación de la sensibilidad y rango lineal de los métodos analíticos.
Objetivos: Geralmente, um novo método analítico para publicação em um periódico científico deve relatar alguns parâmetros para afirmar que a técnica tem validade e sensibilidade aceitável em contraste com outros métodos. Os parâmetros mais comumente relatados são limite de detecção (LDD), limite de quantificação (LDQ) e limite inferior de quantificação (LIDQ). Recentemente, o LIDQ foi selecionado por pesquisadores para mostrar o menor nível de concentração que pode ser determinado. Com base nas diretrizes do FDA, alguns critérios devem ser considerados ao relatar o LIDQ. Métodos: Neste estudo, métodos analíticos relatados anteriormente foram investigados para verificar se eles consideravam os critérios do FDA (desvio padrão relativo do LIDQ, relação sinal-ruído e erro retrocalculado para LIDQ). Além dos critérios da diretriz da FDA, os critérios estabelecidos com base na equação da curva de calibração e na faixa linear foram calculados para confirmar a validade do LIDQ relatado. Resultados: A análise dos dados indica que a maioria dos valores de LIDQ não são definidos com base nas diretrizes do FDA e não mostram o valor de sensibilidade correto do método analítico relatado. Conclusões: Considerando todos os critérios recomendados para LIDQ, é necessário determinar corretamente a sensibilidade e a faixa linear dos métodos analíticos.
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