Pesticides Analysis by MEKC ESI/MS and Sulfonamides Analysis by MEKC-CZE ESI/MS
Date Issued
2011
Date
2011
Author(s)
Huang, Pei-Chia
Abstract
Because carbamate and urea-type pesticides are netural at wide pH range, MEKC was often used to separate these netural compounds. However, nonvolatile surfactants in MEKC would decrease the sensitiveity of analytes on MS and contaminate the ion source of MS. A liquid-junction/low-flow interface was utilized to reduce the introduction of micelle into ESI source by controlling the EOF of connecting capillary. The signal intensity of pesticide analytes were enhanced about 2-10 fold. With MS/MS detection, 19 pesticide analytes were sucessfully separated and detected. Moreover, carbofuran(one of 19 pesticides) was used to evaluate the quantitative ability of this method. The result showed that a relationship between peak area of EIC and concentration is linear in the range 0.05ppm to 10ppm.
To enhance the separation, a liquid-junction/low-flow interface was utilized to combine MEKC with CZE. The MEKC-CZE method was used for sulfonamide analysis at pH 5.5. With appropriate capillary length (MEKC :CZE=4 :1) and electric field, SMP(5) and SMP(7), which were overlapped in MEKC, were separated in MEKC-CZE. In addition, SMR(2)、STZ(3)、SMP(5) and SMZ(6), which were coeluted in CZE, were also resolved in MEKC-CZE. Therefore, combining these two techniques by proper conditions would improve separation of coeluent in single separation mechanism.
To enhance the separation, a liquid-junction/low-flow interface was utilized to combine MEKC with CZE. The MEKC-CZE method was used for sulfonamide analysis at pH 5.5. With appropriate capillary length (MEKC :CZE=4 :1) and electric field, SMP(5) and SMP(7), which were overlapped in MEKC, were separated in MEKC-CZE. In addition, SMR(2)、STZ(3)、SMP(5) and SMZ(6), which were coeluted in CZE, were also resolved in MEKC-CZE. Therefore, combining these two techniques by proper conditions would improve separation of coeluent in single separation mechanism.
Subjects
MEKC-ESI/MS
carbamate and urea-type pesticides
MS/MS
MEKC-CZE
sulfonamides
Type
thesis
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