TY - JOUR
T1 - Using a postcolumn-infused internal standard for correcting the matrix effects of urine specimens in liquid chromatography-electrospray ionization mass spectrometry
AU - Liao, Hsiao Wei
AU - Chen, Guan Yuan
AU - Tsai, I. Lin
AU - Kuo, Ching Hua
N1 - Funding Information:
This study was supported by the National Science Council of Taiwan ( NSC 102-2325-B-002-037 and NSC 102-2319-B-002-002 ). The authors thank the NTU Integrated Core Facility for Functional Genomics of National Research Program for Genomic Medicine of Taiwan for technical assistance.
PY - 2014/1/31
Y1 - 2014/1/31
N2 - Matrix effects (MEs) are a major problem affecting the quantitative accuracy of liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) when analyzing complicated samples. While analyzing urine specimens, the wide diversity of endogenous materials and different urine concentrations may result in inaccurate quantification. In this study, we propose a postcolumn-infused internal standard (PCI-IS) strategy for universal correction of MEs in urine specimens. MEs can be effectively corrected by dividing the target analyte signal intensity by the PCI-IS intensity. To evaluate the performance of PCI-IS, we used 6 benzodiazepine (BZD) drugs in 5 different concentrations of urine matrixes as a test model. The divergence of the BZD drug signal responses in 5 different urine matrixes was expressed using their respective coefficients of variation (CV) to evaluate the efficiency of using PCI-IS in correcting matrix effects. The CV of the BZD drug signal intensities in these 5 different concentrations of the urine matrixes were reduced from 10 to 30% to less than 10% when the PCI-IS correction method was employed. When the PCI-IS method was used to correct the 6 BZDs in 25 real human urine samples, over 90% of the test results exhibited quantification errors of less than 20%, and all of the test results had quantification errors of less than 30%. These results demonstrate that the PCI-IS method can resolve the problem of inaccurate quantification that arises from the diversity of urine specimens. The PCI-IS method is particularly useful for clinical analysis or forensic toxicology to improve the quantification accuracy in an economical way.
AB - Matrix effects (MEs) are a major problem affecting the quantitative accuracy of liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) when analyzing complicated samples. While analyzing urine specimens, the wide diversity of endogenous materials and different urine concentrations may result in inaccurate quantification. In this study, we propose a postcolumn-infused internal standard (PCI-IS) strategy for universal correction of MEs in urine specimens. MEs can be effectively corrected by dividing the target analyte signal intensity by the PCI-IS intensity. To evaluate the performance of PCI-IS, we used 6 benzodiazepine (BZD) drugs in 5 different concentrations of urine matrixes as a test model. The divergence of the BZD drug signal responses in 5 different urine matrixes was expressed using their respective coefficients of variation (CV) to evaluate the efficiency of using PCI-IS in correcting matrix effects. The CV of the BZD drug signal intensities in these 5 different concentrations of the urine matrixes were reduced from 10 to 30% to less than 10% when the PCI-IS correction method was employed. When the PCI-IS method was used to correct the 6 BZDs in 25 real human urine samples, over 90% of the test results exhibited quantification errors of less than 20%, and all of the test results had quantification errors of less than 30%. These results demonstrate that the PCI-IS method can resolve the problem of inaccurate quantification that arises from the diversity of urine specimens. The PCI-IS method is particularly useful for clinical analysis or forensic toxicology to improve the quantification accuracy in an economical way.
KW - Benzodiazepine (BZD)
KW - LC-ESI-MS
KW - Matrix effects
KW - Postcolumn-infused internal standard (PCI-IS)
KW - Urine concentrations
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U2 - 10.1016/j.chroma.2013.12.066
DO - 10.1016/j.chroma.2013.12.066
M3 - Article
C2 - 24394148
AN - SCOPUS:84892501821
SN - 0021-9673
VL - 1327
SP - 97
EP - 104
JO - Journal of Chromatography A
JF - Journal of Chromatography A
ER -