| Title |
Response normalized liquid chromatography nanospray ionization mass spectrometry
|
|---|---|
| Published in |
Journal of the American Society for Mass Spectrometry, October 2007
|
| DOI | 10.1016/j.jasms.2007.07.022 |
| Pubmed ID | |
| Authors |
Ragu Ramanathan, Ruyun Zhong, Neil Blumenkrantz, Swapan K. Chowdhury, Kevin B. Alton |
| Abstract |
The widely different LC-MS response observed for many structurally different compounds limits the use of LC-MS in full scan detection mode for quantitative determination of drugs and metabolites without using reference standard. The recently introduced nanospray ionization (NSI) technique shows comparable MS response for some compounds under non-LC-MS conditions. However, in the presence of numerous endogenous compounds commonly associated with biological samples such as urine, plasma, and bile, LC-MS is required to separate, detect, identify, and measure individual analytes. An LC-NSI-MS system was devised and the MS response obtained in this system for a variety of pharmaceutical drugs and their metabolites. The set-up involves two high-performance liquid chromatography (HPLC) systems, a chip-based NSI source and a quadrupole-time-of-flight (Q-TOF) mass spectrometer. Herein this is referred to as the response normalized-liquid chromatography NSI-MS (RNLC-NSI-MS) system. One HPLC unit performs the analytical separation, while the other unit adds solvent post-column with an exact reverse of the mobile phase composition such that the final composition entering the NSI source is isocratic throughout the entire HPLC run. The data obtained from four different structural classes of compounds [vicriviroc (VCV), desloratadine (DL), tolbutamide, and cocaine] and their metabolites indicate that by maintaining the solvent composition unchanged across the HPLC run, the influence of the solvent environment on the ionization efficiency is minimized. In comparison to responses obtained from radiochromatograms, responses from conventional LC-ESI-MS overestimated the VCV and DL responses, respectively, by 6- and 20-fold. Although VCV and DL responses obtained using LC-NSI-MS are within 2- to 6-fold from the respective radiochromatographic responses, the response normalization modification results in nearly uniform LC-NSI-MS response for all compounds evaluated. |
Mendeley readers
The data shown below were compiled from readership statistics for 41 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 41 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 14 | 34% |
| Student > Ph. D. Student | 7 | 17% |
| Student > Bachelor | 5 | 12% |
| Student > Master | 2 | 5% |
| Lecturer | 1 | 2% |
| Other | 5 | 12% |
| Unknown | 7 | 17% |
| Readers by discipline | Count | As % |
|---|---|---|
| Chemistry | 14 | 34% |
| Agricultural and Biological Sciences | 7 | 17% |
| Pharmacology, Toxicology and Pharmaceutical Science | 6 | 15% |
| Biochemistry, Genetics and Molecular Biology | 3 | 7% |
| Environmental Science | 2 | 5% |
| Other | 3 | 7% |
| Unknown | 6 | 15% |
Attention Score in Context
This research output has an Altmetric Attention Score of 6. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 06 March 2021.
All research outputs
#5,611,796
of 25,837,817 outputs
Outputs from Journal of the American Society for Mass Spectrometry
#571
of 3,906 outputs
Outputs of similar age
#16,401
of 87,207 outputs
Outputs of similar age from Journal of the American Society for Mass Spectrometry
#3
of 24 outputs
Altmetric has tracked 25,837,817 research outputs across all sources so far. Compared to these this one has done well and is in the 75th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 3,906 research outputs from this source. They receive a mean Attention Score of 3.9. This one has done well, scoring higher than 78% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 87,207 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 71% of its contemporaries.
We're also able to compare this research output to 24 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 70% of its contemporaries.