The aim of this study was to assess the impact of hanging position of hunted pheasant carcasses (secured by the head as compared to hanging position secured by the legs) on the biogenic amine concentration in the thigh and breast muscles. The carcasses of feathered game (Phasianus colchicus), left entirely untreated after hunting and placed in a storage space at a pre-set temperature of 7 °C for 21 days were used in the study. Samples of breast and thigh muscles were taken at regular weekly intervals. Measurement of biogenic amines (putrescine, cadaverine, tyramine, tryptamine, histamine, phenylethylamine) was based on high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry. Higher biogenic amine concentrations were detected in the muscles (both breast and thigh) of pheasants hanging by their legs compared to pheasants hanging by their heads (no statistically significant difference in biogenic amine concentration between monitored groups was, however, established). Higher concentrations of biogenic amines were found in the thigh muscles compared to breast muscles in both monitored groups. The obtained results show, that hanging the carcasses of pheasants during storage by the head is more suitable method in term of biogenic amine concentration than storing carcasses hanging by the legs.
Authors:A. Kumar, R.K. Dubey, K. Kant, D. Sasmal, M. Ghosh, and N. Sharma
Deltamethrin, a well-known type 2 synthetic pyrethroid insecticide, is a widespread environmental toxicant. It has potential to accumulate in body fluids and tissues due to its lipophilic characteristics. The immune system is among the most sensitive targets regarding toxicity of environmental pollutants. Various methods are available in the literature to analyze deltamethrin (DLM) concentration in plasma and tissues, but regarding the immune organs, only one gas chromatography–tandem mass spectrometry (GC–MS/MS) method (on spleen tissues) has been reported. In the present investigation, a rapid and sensitive high-performance liquid chromatography (HPLC) method has been developed and validated to determine DLM concentration in plasma, thymus, and spleen using zaleplone as an internal standard. Liquid chromatography (LC) separation is performed on an Agilent Zorbax® C8 column (250 mm × 4.6 mm, i.d., 5 μm) with isocratic elution using a mobile phase consisting of acetonitrile–5 mM KH2PO4 (70:30, v/v) at a flow rate of 1 mL min−1. The lower limit of quantification (LLOQ) for DLM is 10 ng mL−1 (plasma, thymus, and spleen). The method has been validated in terms of establishing linearity, specificity, sensitivity, recovery, accuracy, and precision (intra- and inter-day) and stabilities study. This validated method was successfully applied to a pharmacokinetic and tissue distribution study of DLM in mice.
Authors:Longyuan Wang, Xiaoxiao Hu, Hong Zhu, Xiaotian Zhang, Chuan Wang, and Zhiwu Han
A rapid, selective, sensitive, and simple method for simultaneous determination of tigecycline and its epimer in human plasma samples was developed and validated by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Sample preparation involved one-step protein precipitation by adding 0.1% formic acid–methanol and phosphate buffer (PB) solution to the plasma. Chromatographic separation was obtained with XBridge BEH C18 column (3.5 μm, 50 × 4.6 mm) through a 9.5-min gradient mobile phase at the flow rate of 0.6 mL min−1 at 4 °C. The calibration curves were linear over concentration 5.00–2000 ng mL−1 with correlation coefficient greater than 0.998. Intra-batch and inter-batch accuracy of the assay were in the ranges of −2.90% to 3.00%, and the corresponding precision was less than 6.97%. The extraction recovery of tigecycline and its epimer with the current method were 87.2% and 76.9%, respectively. The applied LC–MS/MS method was shown to be sufficiently sensitive and will be suitable for pharmacokinetic studies.
Authors:M. Nurul Islam, F. Downey, and C. K.-Y. Ng
Scutellaria L. is a diverse genus of the Lamiaceae (Labiatae) family of over 300 herbaceous plants commonly known as skullcaps. Various species of Scutellaria are used as ethnobotanical herbs for the treatment of ailments like cancer, jaundice, cirrhosis, anxiety, and nervous disorders. Scutellaria incana L., commonly known as the Hoary skullcap, is a traditional medicinal plant used by native Americans as a sedative for nervousness or anxiety. S. incana metabolites were identified by comparing their high-performance liquid chromatography (HPLC) retention times and mass spectra with those of the corresponding authentic standards. Where standards were unavailable, the structures were characterized on the basis of their tandem mass spectrometry (MS/MS) spectra following collision-induced dissociation (CID) and the accurate masses of the corresponding deprotonated molecules [M-H]− (mass accuracy ± 5 ppm). A total of 40 flavonoids, including two phenolic glycosides, were identified from leaves, stems, and roots of S. incana. Differences in the flavonoid composition between leaves, stems, and roots in S. incana were observed although the flavonoid profile of S. incana is consistent with other Scutellaria species. Further work should focus on assessing the potential of S. incana as a source of these bioactive metabolites.
Authors:S.T. Yang, X. Wu, W. Rui, J. Guo, and Y.F. Feng
A rapid method has been used for simultaneous identification of both hydrophilic and lipophilic compounds from Radix Salviae Miltiorrhizae (RSM, the root of Salvia miltiorrhiza BGE.) by ultra-performance liquid chromatography/quadrupole time-offlight mass spectrometry (UPLC/Q-TOF-MS). A total of 58 compounds extracted by methanol were detected and tentatively identified within 20 min, including hydrophilic phenolics, lipophilic diterpenoids, a verbascose, and several organic acids. These compounds were separated on an Acquity UPLC BEH C18 column and identified based on tandem mass spectrometry (MS/MS) fragmentation patterns under the positive and negative ion modes, respectively. Among them, micranthin B and 9-oxo-10E,12Zoctadecadienoic acid were reported in RSM for the first time. Their fragmentation patterns in electrospray ionization (ESI)—MS/MS spectra were first investigated by matching their accurate molecular masses. This contribution presented one of the first reports on the analysis of hydrophilic phenolics and lipophilic diterpenoids from Radix Salviae Miltiorrhizae using UPLC/Q-TOF-MS. The results demonstrated that UPLC/Q-TOF-MS method could be applied to rapidly and expediently describe and provide comprehensive chemical information for simultaneous analysis of two different polar components in RSM.
Authors:A. Kwiecień, K. Piątek, P. Żmudzki, and J. Krzek
A simple, selective, and sensitive thin-layer chromatographic—densitometric method has been developed for the determination of sulfasalazine besides its possible impurities in pharmaceutical preparations. The mobile phase was composed of ethyl acetate—methanol—ammonia 25% 10:7:3 (υ/υ/υ), and the stationary phase was aluminum plates precoated with silica gel 60 F254 that enabled to obtain well resolved peaks of sulfasalazine and its impurities. The developed chromatograms were analyzed densitometrically at λ = 360 nm. RF values and ultraviolet (UV) spectra were used to identify the compounds. The developed method is highly sensitive (limit of detection [LOD] = 17.11 ng spot−1, limit of quantitation [LOQ] = 51.84 ng spot−1), precise (relative standard deviation [RSD] = 1.43%–4.28%), and accurate (RSD = 1.64%–4.27%). The linearity of the method was checked within the range 20–120 ng spot−1. The method was successfully applied for the determination of sulfasalazine in pharmaceutical preparations besides its impurities. The structures of impurities present in the standard substance and in pharmaceutical preparations were established by ultra-performance liquid chromatography—tandem mass spectrometry (UPLC—MS/MS) technique.
Authors:Yan-Mei Zhong, Xun-Long Zhong, Ji-Hua Wang, and Liang Han
Patrinia scabiosaefolia Fisch. (PSF), a well-known traditional Chinese medicine, has been demonstrated to show therapeutic effects on inflammatory bowel disease. In this study, a rapid and sensitive method using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) was developed for identification of the major constituents in PSF. The separation analysis was performed on Waters Acquity UPLC system, and the accurate mass of molecules and their fragment ions were determined by Q-TOF-MS. Thirty-one constituents, including triterpenoids, iridoids, flavonoids, and organic acids were detected and tentatively deduced on the basis of their element compositions, tandem mass spectrometry (MS/MS) data, and relevant literatures. Twelve constituents were discovered for the first time in PSF. The results demonstrated that hederagenin-type and oleanolic acid-type saponins were the main constituents of PSF. Our work provides a certain foundation for further quantitation of major chemical constituents and in vivo pharmacokinetic studies of PSF. Moreover, the analytical approach developed herein has proven to be generally applicable for profiling the chemical constituents in traditional Chinese medicines (TCMs) and other complicated mixtures.
Authors:J. Kuc, A. Grochowalski, S. Mach, and D. Placha
This paper is focused on the determination of three hexabromocyclododecane isomers, α, β, and γ, in the tissue of the most commonly consumed marine and farmed fish in Central Europe. The analytical procedure contains multiple steps: extraction, dialysis using semipermeable membranes, and a clean-up step using a silica gel column. Hexabromocyclododecane (HBCD) isomers were determined by sensitive isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method which is characterized by a low limit of detection (1 pg g−1 fresh weight). The recovery values obtained for individual isomers were in the range of 89–124%. The γ-HBCD isomer was detected in all samples. This isomer also had the largest percentage in comparison with the other isomers, except in salmon, in which the α-HBCD isomer was more abundant. The highest level of total HBCD was measured in mackerel (650 ± 195 pg g−1 fresh weight). Cluster analysis allowed the differentiation of groups of objects and the display of objects based on the degree of integration within the same group. Spearman’s rank correlation indicated no statistically significant difference between the levels of HBCD and the fat content in the fish samples.
Authors:Su-su Bao, Jian Wen, Teng-hui Liu, Bo-wen Zhang, Chen-chen Wang, and Guo-xin Hu
Olmutinib (Olita™) is an oral third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) which is used to treat non-small cell lung cancer (NSCLC). A simple, rapid, and sensitive method based on ultra-performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) has been developed for the determination of olmutinib. Sample preparation was performed following simple one-step protein precipitation with acetonitrile. Olmutinib and internal standard (dasatinib) were separated on an Eclipse Plus C18 RRHD (2.1 × 50 mm, 1.8 μm) column. The mobile phase consisted of acetonitrile–0.1% formic acid in water with gradient elution. A total run time of 1.7 min was achieved. Detection was performed on a positive-ion electrospray ionization mass spectrometer in multiple reaction monitoring (MRM) mode, using transitions of m/z 487.2 → 402.1 for olmutinib and m/z 488.2 → 401 for dasatinib (IS), respectively. The calibration curve (R2 = 0.999) was linear over the range of 1–500 ng/mL. The recovery of olmutinib ranged from 85.8% to 95.5%. This method can be applied to pharmacokinetic studies of olmutinib.
Authors:Y. Wang, M. Wang, J. Li, S. Yao, J. Xue, W. Zou, and C. Hu
An improved ion-pairing reversed-phase high-performance liquid chromatography method coupled with evaporative light scattering detection (HPLC-ELSD) was developed to determine spectinomycin and its related substances in commercial samples. The method was validated in accordance with International Conference on Harmonization (ICH) guidelines. The specificity of the HPLC-ELSD method was similar to that of the European Pharmacopoeia (Ph. Eur.) method, and repeatability and robustness were markedly improved relative to other reported methods due to our empirical evaluation of separation columns. Indeed, it is a more specific assay of spectinomycin than traditional microbiological techniques. The HPLC-ELSD method was used to evaluate the impurity profiles of eight compounds in seven spectinomycin batches from five different companies. Liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was employed to characterize the structures of these compounds. Though the HPLC-ELSD method was not as sensitive as the Ph. Eur. method, its limit of quantitation (LOQ) (0.16%) was lower than the disregard limit (0.3%) described by the Ph. Eur. 7.0. This suggests that the HPLC-ELSD method is appropriate for routine analysis of spectinomycin and its related substances.