A preliminary multi-stable-isotopic evaluation of three synthetic pathways of Topiramate

Jasper, John P.; Weaner, Larry E.; Duffy, B.J.

doi:10.1016/j.jpba.2005.03.011

Cited by 18 publications

(8 citation statements)

References 16 publications

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“…There was not enough information available on the primary source of these samples to determine if this clustering is due to these samples being from a common batch or is coincidental. However, this is the type of pattern that has been found for other synthetic substances and attributed as evidence of a common origin . The two case samples are also plotted in Figure as red or black dots and they fall close to one of the clusters of library samples.…”

Section: Resultsmentioning

confidence: 51%

Stable isotope measurements to differentiate sources of monofluoroacetate in a blackmail case

Hale

Schofield

Connor

et al. 2019

Rapid Comm Mass Spectrometry

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Rationale: Stable isotope ratios can provide a 'fingerprint' to enable differentiation of sources of monofluoroacetate (MFA), hence providing a means to eliminate potential sources of MFA in a blackmail case involving the contamination of milk. Methods: The stable isotopic compositions (δ 2 H, δ 13 C and δ 18 O values) of a library of 43 samples of MFA were determined and multivariate models constructed to differentiate samples of different composition. The data from the MFA library were compared with those obtained from MFA extracted from contaminated milk powder (the case samples). The isotopic composition of the extracted samples was measured on dichloroaniline derivatives.Results: A wide range of values was found for δ 2 H, δ 13 C and δ 18 O of the MFA samples, much greater than the analytical repeatability between subsamples. Stable isotope data, therefore, provide a means of distinguishing samples of MFA. Of the 43 MFA samples tested, all but 6 could be eliminated as potential sources of the contamination, i.e. they had a distinctly different isotopic composition such that they must have had different histories and/or origins. Conclusions:Stable isotope measurements of bulk and derivatized MFA provide an effective means of discriminating MFA samples. Three of the library samples that could not be differentiated from the case samples were directly connected to the suspect, and this evidence contributed to the suspect's admission of guilt.

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Section: Resultsmentioning

confidence: 51%

Stable isotope measurements to differentiate sources of monofluoroacetate in a blackmail case

Hale

Schofield

Connor

et al. 2019

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

show abstract

“…This research has focussed mainly on comparing illicit drug seizures with regard to their source. A survey of the literature revealed a large number of measured isotope ratios for individual drug and drug precursor samples . The isotope ratio variation for carbon ( n = 883), nitrogen ( n = 709), and hydrogen ( n = 567) are shown in Figure .…”

Section: Resultsmentioning

confidence: 99%

“…A survey of the literature revealed a large number of measured isotope ratios for individual drug and drug precursor samples. [18][19][20][21] The isotope ratio variation for carbon (n = 883), nitrogen (n = 709), and hydrogen (n = 567) are shown in Figure 2.…”

Section: Variations In Isotopic Abundancementioning

confidence: 99%

“…A potential limitation of this approach when used for quantitative analysis is that if the analyte in the sample is from a different source to the reference standard used for calibration (as is usually the case in a forensic toxicology setting), it may not contain the same ratio of isotopologues. Indeed, it has been established that isotopic variation can occur in pharmaceuticals manufactured using different synthetic pathways . This variation may lead to error in the calculated concentration.…”

Section: Introductionmentioning

confidence: 99%

“…Indeed, it has been established that isotopic variation can occur in pharmaceuticals manufactured using different synthetic pathways. [18][19][20] This variation may lead to error in the calculated concentration. It appears there has been little consideration of this possibility in the literature to date.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Increasing the linear dynamic range in LC–MS: is it valid to use a less abundant isotopologue?

Trobbiani

Stockham

Scott

2017

Drug Testing and Analysis

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Liquid chromatography-mass spectrometry (LC-MS) has quickly become the analytical method of choice in forensic toxicology laboratories due to its ability to detect a very wide range of compounds in a single analysis. One of the major limitations of LC-MS however, is a relatively limited linear dynamic range for quantitation. A new approach to combating this problem is to use the [ M + H] isotope mass peak for quantitation, thereby reducing saturation at the detector and extending the linear range. This is particularly useful in full-scan applications, such as quadrupole-time-of-flight (QTOF) mass spectrometry, where the isotopic mass peaks are acquired as a matter of course. Due to the variation in abundance of naturally occurring isotopes for common elements, especially C, this technique has the potential to lead to additional quantitative error. Through a review of published isotope ratio mass spectrometry data, we have assessed this potential for error and found that it is likely to be less than 2% and unlikely to be more than 4%, although this may not apply to compounds containing high numbers of nitrogen or sulphur atoms. This additional potential error must be considered before using this technique as it may not be appropriate for all applications. We have deemed it fit for purpose for our application and demonstrate the applicability of this technique to a quantitative LC-TOF method. © 2017 Commonwealth of Australia. Drug Testing and Analysis © 2017 John Wiley& Sons, Ltd.

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Stable Isotope Forensics

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A preliminary multi-stable-isotopic evaluation of three synthetic pathways of Topiramate

Cited by 18 publications

References 16 publications

Stable isotope measurements to differentiate sources of monofluoroacetate in a blackmail case

Stable isotope measurements to differentiate sources of monofluoroacetate in a blackmail case

Increasing the linear dynamic range in LC–MS: is it valid to use a less abundant isotopologue?

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