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DeterminaĆ§Ć£o de glifosato em amostras alimentares (frutos e vegetais)
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O glifosato Ć© o herbicida sistĆ©mico mais utilizado. Inicialmente considerado inofensivo, a sua inocuidade tem sido questionada Ć medida que surgem estudos cientĆficos que relatam efeitos negativos associados Ć sua exposiĆ§Ć£o. Atualmente a toxicidade do glifosato Ć© controversa na comunidade cientĆfica e entre entidades reguladoras. Submetido para reavaliaĆ§Ć£o pela EFSA, sĆ³ em 2022 serĆ” conhecida a decisĆ£o final, prevendo-se medidas mais restritas. O desenvolvimento de mĆ©todos com elevada sensibilidade e reprodutibilidade Ć© essencial para se obterem resultados consistentes e fiĆ”veis que fundamentem decisƵes que transmitam seguranƧa. Com efeito, neste trabalho, foi desenvolvida e otimizada uma metodologia para quantificaĆ§Ć£o de glifosato em matrizes vegetais por Cromatografia LĆquida de Ultra Elevada EficiĆŖncia acoplada Ć Espetrometria de Massa em Tandem (UHPLC-MS/MS). O desenvolvimento de um processo de extraĆ§Ć£o simples em combinaĆ§Ć£o com a diluiĆ§Ć£o de 1:10 e congelamento dos extratos das amostras, permitiu alcanƧar bons resultados cromatogrĆ”ficos. Simultaneamente, o priming da coluna Hypercarb com extrato de espinafres reduz o tempo de retenĆ§Ć£o, e melhora a forma dos picos cromatogrĆ”ficos. O mĆ©todo foi validado para morango e curgete, de acordo com o guia SANTE/12682/2019 para a: linearidade, gama de trabalho,
repetibilidade, precisĆ£o intermĆ©dia e exatidĆ£o. O mĆ©todo apresenta boa linearidade (R<0,9995), abrangendo uma gama de trabalho de 0,00500 Ī¼g/mL a 0,100 Ī¼g/mL, tendo limite de deteĆ§Ć£o (LD) de 0,00330 mg/kg e limite de quantificaĆ§Ć£o (LQ) de 0,0100 mg/kg. As matrizes avaliadas apresentam uma taxa de recuperaĆ§Ć£o mĆ©dia de 93,1%, para o morango, e 86,6% para a curgete. A repetibilidade e precisĆ£o intermĆ©dia do mĆ©todo variaram entre 5,97 e 12,2% e entre 10,2 e 15,7%, respetivamente. A incerteza do mĆ©todo foi inferior a 50%. Comprovou-se que o mĆ©todo Ć© aplicĆ”vel para anĆ”lises de rotina, visto ter sido possĆvel quantificar o glifosato para valores inferiores ao LQ, com taxas de recuperaĆ§Ć£o aceitĆ”veis.
Glyphosate is the most used systemic herbicide. Initially considered inoffensive, its harmlessness has been questioned as scientific studies report negative effects associated with its exposure appear. Currently the toxicity of glyphosate is controversial in the scientific community and among regulators. Submitted for reassessment by EFSA only on 2022 the final decision will be known, with more restricted measures being expected. The development of methods with high sensitivity and reproducibility is essential to achieve consistent and reliable results that support decisions that convey safety. Moreover, in this work, a method for quantification of glyphosate in plant matrices was developed and optimized by Ultra High Performance Liquid Chromatography coupled to Tandem Mass Spectrometry (UHPLC-MS/MS). The development of a simple extraction process in combination with dilution of 1:10 and freezing of the samples extracts, allowed good chromatographic results. Simultaneously, priming the Hypercarb column with spinach extract reduced the retention time and improved the shape of chromatographic peaks. The method was validated for strawberry and courgette, according to the Guide SANTE/12682/2019 for: linearity, working range, repeatability, intermediate precision, and accuracy. The method has a good linearity (R<0.9995), covering a working range from 0.00500 Ī¼g/mL to 0.100 Ī¼g/mL, with a detection limit (LD) of 0.00330 mg/kg and quantification limit (LQ) of 0.0100 mg/kg. The evaluated matrices presented an average recovery rate of 93.1% for strawberry, and 86.6% for courgette. Method repeatability and intermediate precision ranged from 5.97 to 12.2% and between 10.2 and 15.7%, respectively. The uncertainty of the method was less than 50%. It has been proved that the method is applicable to routine analysis, as it was possible to quantify glyphosate for values lower than the LQ, with an acceptable recoveries rate.
Glyphosate is the most used systemic herbicide. Initially considered inoffensive, its harmlessness has been questioned as scientific studies report negative effects associated with its exposure appear. Currently the toxicity of glyphosate is controversial in the scientific community and among regulators. Submitted for reassessment by EFSA only on 2022 the final decision will be known, with more restricted measures being expected. The development of methods with high sensitivity and reproducibility is essential to achieve consistent and reliable results that support decisions that convey safety. Moreover, in this work, a method for quantification of glyphosate in plant matrices was developed and optimized by Ultra High Performance Liquid Chromatography coupled to Tandem Mass Spectrometry (UHPLC-MS/MS). The development of a simple extraction process in combination with dilution of 1:10 and freezing of the samples extracts, allowed good chromatographic results. Simultaneously, priming the Hypercarb column with spinach extract reduced the retention time and improved the shape of chromatographic peaks. The method was validated for strawberry and courgette, according to the Guide SANTE/12682/2019 for: linearity, working range, repeatability, intermediate precision, and accuracy. The method has a good linearity (R<0.9995), covering a working range from 0.00500 Ī¼g/mL to 0.100 Ī¼g/mL, with a detection limit (LD) of 0.00330 mg/kg and quantification limit (LQ) of 0.0100 mg/kg. The evaluated matrices presented an average recovery rate of 93.1% for strawberry, and 86.6% for courgette. Method repeatability and intermediate precision ranged from 5.97 to 12.2% and between 10.2 and 15.7%, respectively. The uncertainty of the method was less than 50%. It has been proved that the method is applicable to routine analysis, as it was possible to quantify glyphosate for values lower than the LQ, with an acceptable recoveries rate.
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Glifosato UHPLC-MS/MS ValidaĆ§Ć£o de MĆ©todos Alimentos de origem vegetal