Quantitation and Mass Spectrometric Data of Drugs and Isotopically Labeled Analogs

Liu, Ray H.; Canfield, Dennis V.; Wang, Sheng-Meng

doi:10.1201/9781420094985

Cited by 7 publications

(14 citation statements)

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“…13 The synthesis of D 3 COsubstituted arenes is important with regard to drug derivation for pharmacological 14 and analytical purposes related to drug abuse monitoring and quantitative detection of, for example, THC derivatives. 15 The disadvantages of the existing protocols for deuterium or D 3 CO-derivation such as harsh reaction conditions, low selectivities and the use of toxic reagents are manifold, and many attempts have been made to overcome them. Monodeuterated compounds have been isolated in good yields by replacement of diazonium groups through deuterium using thiophenol-d 1 16 or deuterated dimethylformamide in combination with FeSO 4 .…”

mentioning

confidence: 99%

Solid phase synthesis of selectively deuterated arenes

Vanderheiden

Bulat

Zevaco³

et al. 2011

Chem. Commun.

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confidence: 99%

Solid phase synthesis of selectively deuterated arenes

Vanderheiden

Bulat

Zevaco³

et al. 2011

Chem. Commun.

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“…Lorazepam has been analyzed in urine utilizing both MTBSTFA derivatization [23] and a dual derivatization procedure with MTBSTFA and TFAA [24]. The di-TMS derivative of lorazepam has also been formed [25].…”

Section: Figurementioning

confidence: 99%

“…Amphetamine [17] TFAA [2,19,20] MBTFA [4] Cyclohexanone [24] Trifluoroacetylacetone [25] 2C-I [15] TFAA [15]…”

Section: Underivatized Acylation Silylation Alkylationmentioning

confidence: 99%

Formation and identification of novel derivatives of primary amine and zwitterionic drugs

2018

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Gas chromatography-mass spectrometry (GC-MS) is a "workhorse" in the analysis of controlled substances in forensic laboratories. However, many drugs are not amenable to GC-MS due to thermal instability, non-ideal interactions in the column, or both. To improve the suitability of a molecule for analysis by GC-MS, derivatization can be employed. Derivatization replaces a labile hydrogen in the analyte molecule with a more stable functional group. In this paper, three different derivatization agents were tested for effectiveness with two classes of drugs: primary amines (i.e., amphetamine and 2C-I) and zwitterions (i.e., gabapentin, lorazepam, vigabatrin, pregabalin, and clorazepate). Trifluoroacetic anhydride (TFAA) was used as an acylating agent and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) was used as a silylating agent. Dimethylformamide-dimethyl acetal (DMF-DMA), which has not been previously used for derivatization of drugs, was used as an alkylating agent. DMF-DMA was found to form dimethylaminomethylene derivatives with several primary amines and zwitterions. Amphetamine, 2C-I, gabapentin, and lorazepam were all detected in their underivatized form but generally suffered from peak asymmetry and band broadening. Derivatization resulted in drastic improvements in their chromatographic behavior. Vigabatrin, clorazepate and pregabalin were not detectable in their underivatized form. However, the trimethylsilyl (TMS) derivative of clorazepate was readily detected by GC-MS, as were the TMS and trifluoroacetyl (TFA) derivatives of vigabatrin. Derivatization of pregabalin was not successful, resulting in multiple chromatographic peaks with each derivatization agent. The mass spectra of several derivatives were not found in commercially available mass spectral databases. Hence, those spectra are reported here with interpretation of their fragmentation.

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“…in quantitative GC-MS analysis'; 12 and (c) compiled a comprehensive list of CC data for ion-pairs that may be adopted for designating the drug analytes and their ISs in MSbased methodologies. 10 In this current study, we have carried out this line of research one step further. Specifically, the novel approach 12 reported earlier will be extended (a) to examine whether a specific set of CC values is accurate; and (b) to differentiate whether the observed non-linear calibration curve is caused by detector fatigue or the CC phenomenon.…”

Section: Introductionmentioning

confidence: 99%

Detector response and intensity cross-contribution as contributing factors to the observed non-linear calibration curves in mass spectrometric analysis

Sie

Chen

Chang³

et al. 2011

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It is a common knowledge that detector fatigue causes a calibration curve to deviate from the preferred linear relationship at the higher concentration end. With the adaptation of an isotopically labeled analog of the analyte as the internal standard (IS), cross-contribution (CC) of the intensities monitored for the ions designating the analyte and the IS can also result in a non-linear relationship at both ends. A novel approach developed to assess 'the extent and the effect of [CC]… in quantitative GC-MS analysis' can be extended (a) to examine whether a specific set of CC values is accurate; and (b) to differentiate whether the observed non-linear calibration curve is caused by detector fatigue or the CC phenomenon. Data derived from the exemplar secobarbital (SB)/SB-d(5) system (as di-butyl-derivatives) are used to illustrate this novel approach. Comparing the non-linear nature of calibration data that are empirically observed to that derived from theoretical calculation (with the incorporation of adjustment resulting from the ion CC phenomenon), supports the conclusions that (a) both CC and detector fatigue contribute significantly to the observed non-linear nature of the calibration curve based on ion-pair m/z 207/212; and (b) detector fatigue is the dominating contributor when the calibration curve is based on ion-pair m/z 263/268.

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Quantitation and Mass Spectrometric Data of Drugs and Isotopically Labeled Analogs

Cited by 7 publications

References 0 publications

Solid phase synthesis of selectively deuterated arenes

Solid phase synthesis of selectively deuterated arenes

Formation and identification of novel derivatives of primary amine and zwitterionic drugs

Detector response and intensity cross-contribution as contributing factors to the observed non-linear calibration curves in mass spectrometric analysis

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