Matrix effect in pesticide analysis by ultra fast liquid chromatography coupled to mass spectrometry

Abstract

O presente trabalho descreve os resultados de um estudo de diferentes variáveis que influenciam o efeito matriz (EM). Para isso, optamos entre quatro diferentes solventes de extração e quatro métodos de limpeza, a fim de determinar qual é o método que produz um menor efeito matriz e uma maior resposta cromatográfica para os 18 compostos testados. Estudamos também a variação das respostas cromatográficas usando cinco tipos diferentes de frutas. Finalmente, foram avaliadas diferentes relações analito/matriz. Os resultados mostraram que as respostas significativamente melhores (P < 0,05) foram obtidas usando a mistura de três diferentes absorventes, e o negro de carbono grafitizado ocasionou a maior supressão da ionização. Das cinco matrizes avaliadas, descobrimos que as uvas e extrato de tomates causaram maior efeito matriz, enquanto que a manga e maçã apresentaram os melhores sinais cromatográficos. Finalmente, encontramos uma correlação negativa entre a proporção de analito/matriz e a supressão da ionização.In this work a study of several variables that affect the matrix effects (ME) was performed. The choice was given among four extraction solvents and four different clean-up methods which were compared in order to find the method that produces least ME and gives the highest response for 18 compounds. Variability of ME under identical chromatographic conditions for five fruits was also studied. Finally we evaluated different analyte/matrix ratios to assess the ME. The results showed that the significantly better responses (P < 0.05) were achieved by using the mixture of three absorbents and the use of only Graphitized Carbon Black causes greater suppression of ionization. From the five matrices tested it was found that grapes and tomatoes extract induced a larger ME, meanwhile the use of apple and mango matrices gave responses more like matrix-free standards. Finally, a negative correlation between the suppression of ionization and the compound/ matrix ratio was found.

Multiresidue method for the simultaneous determination of 16 acaricides by modified quick, easy, cheap, effective, rugged, and safe extraction andultra-high performance liquid chromatography coupled with tandem mass spectrometry in citrus

“…The physicochemical properties of analytes had great impact on the extent of matrix effects by affecting the surface adsorption of analytes, electrospray instability, or variable ionization efficiency . Compounds with high surface activity carry greater fraction of excess charge and thereby produce higher ESI response . Therefore, it might be possible that the strong matrix effect of cyflumetofen was due to its high molecular weight (MW = 447.45), which showed fairly higher surface activity than other compounds.…”

“…Several approaches have been proposed to overcome matrix effects among which the most widely used strategy is matrix‐matched standardization . Aspects of the variability of matrix effects in LC–MS/MS have been measured for different pesticides among different matrices . However, to our knowledge, no studies to date have reported the matrix effects of acaricides in matrices of citrus pulp, whole citrus, and citrus peel by LC–MS/MS.…”

Evaluation of method performance and matrix effect for 57 commonly used herbicides in some vegetable families using LC-MS/MS determination

“…Signal enhancement of ion-response can be attributed to various vegetables matrices, because of high surface activity resulting in fine droplets in +ESI: (Positive-Electro-Spray Ionization) response. Where the strong affinity for the surface due to the presence of non-polar region, oxygenated groups and reaction targets like carbonyl groups, could increase the ionization process especially, with the presence of co-eluting matrix-components which comply with this reference (Ahumada et al, 2012;Cech et al, 2001;Martínez et al, 2005). Most of the studied herbicides displayed signal suppression in most of studied matrices.…”

Desarrollo de una metodología para el análisis de residuos de plaguicidas en leches mediante cromatografía líquida acoplada a espectrometría de masas

“…Estos resultados corroboran lo planteado acerca de la eliminación de interferentes mediante el cambio de solvente. Empero, este menor efecto matriz no solo es atribuido a la precipitación de algunos de los interferentes, sino también al tipo de interferentes que se pueden extraer con el acetato de etilo, pues a diferencia del acetonitrilo este solvente no extrae los compuestos de alto momento dipolar, los cuales tienen una mayor probabilidad de generar fenómenos de supresión de la señal cromatográfica (Ahumada et al, 2012).…”