Sensitivity enhancement and matrix effect evaluation during summation of multiple transition pairs—case studies of clopidogrel and ramiprilat

Abstract

Sensitivity enhancement via summation of multiple MRM transition pairs is gaining popularity in tandem mass spectrometric assays. Numerous validation experiments describing the assays for two model substrates, clopidogrel and ramiprilat, were performed. The quantitation of clopidogrel was achieved by the summation of transition pairs m/z 322.2 to m/z 212.0 and m/z 322.2 to m/z 184.0, while that of ramiprilat was achieved by the summation of transition pairs m/z 389.2 to m/z 206.1 and m/z 389.2 to m/z156.1. The use of summation approach achieved sensitivities of >2 fold for both compounds as compared with the reported single MRM transition pair assays. The validation experiments addressed some important assay development issues, such as: (a) lack of impact of matrix effect; (b) unequivocal verification of the percentage contribution of each MRM transition pair towards sensitivity; (c) sensitivity enhancement factor achieved by summation approach of MRM transition pairs; and (d) accurate prediction of quality control samples using summation approach vs a single MRM transition pair. In summary, the appropriateness of using two MRM transition pairs for quantitation was demonstrated for both clopidogrel and ramiprilat. Additionally, pharmacokinetic application of the MRM transition pair assays using a summation approach was established for the two compounds.

Quantitative Analysis of Polyethylene Glycol (PEG) and PEGylated Proteins in Animal Tissues by LC-MS/MS Coupled with In-Source CID

“…In-source ions ( m / z 133.1, 177.1, 353.1, 397.2, 441.2) with relatively high abundance were subjected to further dissociation in the positive ESI-MRM mode and the summation of five transitions (see the Experimental Section) were employed to quantify both 40k PEG and ATI-1072 (LLOQ 0.05 μg/mL for both analytes). The approach of using the summation of multiple MRM transitions to increase the sensitivity is now increasingly considered in the LC-MS/MS analysis . In the current study, using the total signals from 5 MRM transitions instead of 1 transition increased the assay sensitivity by at least 3-fold.…”

“…For the quantitative analysis of 40k PEG and ATI-1072, the following MRM (multiple reaction monitoring) transitions of PEG-specific ions were selected: m / z 133.1 → m / z 89.1, m / z 177.1 → m / z 89.1, m / z 353.2 → m / z 89.1, m / z 397.2 → m / z 133.1, and m / z 441.2 → m / z 133.1. To improve assay sensitivity, the summation of the signals from five transitions was used for standard curve and sample analysis . The standard curves with the concentrations ranged from 0.05 to 20 μg/mL were fitted to a quadratic regression model using weighting factors 1/ x . , Concentrations of 40k PEG and ATI-1072 were calculated using the Analyst software (Version 1.6, AB Sciex) based on their MRM responses and standard curves.…”

Simultaneous determination of sacubitrilat and fimasartan in rat plasma by a triple quad liquid chromatography–tandem mass spectrometry method utilizing electrospray ionization in positive mode

“…However, a single SRM transition pair appeared to be adequate for fimasartan to achieve appropriate sensitivity and for IS alprazolam. The summations of SRM transition pairs have been previously used in a beneficial manner to improve the sensitivity of the assays without any compromise in the assay performance (Manjunath Swamy, Kamath, Radha Shekar, Srinivas, & Kristjansson, 2010; Srinivas, 2009b). Before execution of full validation, a long batch ( n = 30/concentration) including LLOQ (5 ng/mL), LQC (15 ng/mL), MQC (6000 ng/mL) and HQC (7500 ng/mL) was run to ensure assay reproducibility.…”

A review of bioanalytical quantitative methods for selected sphingosine 1‐phosphate receptor modulators

“…Another aspect of the study was with respect to summation of responses from two MRM transition pairs to improve the sensitivity of the quantitation (Ferreirós et al, ). Previously, it has been demonstrated that for drugs such as clopidogrel and ramiprilat, sensitivity for analysis can be increased with summation of stable MRM transition pairs; however, it is equally important to ensure that such sensitivity enhancement is devoid of the matrix effect (Manjunath Swamy, Kamath, Radha Shekar, Srinivas, & Kristjansson, ; Srinivas, ).…”