scholarly journals Counterfeit medicines: a pilot study for chemical profiling employing a different proposal of an usual technique

2020 ◽  
Vol 4 (2) ◽  
pp. 19-23
Author(s):  
Maíra Santos ◽  
Alessandro Kahmann ◽  
Luiza Manica Caffarate ◽  
Laura Ribas Ucha ◽  
Renata Pereira Limberger ◽  
...  
Keyword(s):  
Extraction Procedure ◽  
Principal Component ◽  
Standard Technique ◽  
Hierarchical Cluster ◽  
Pilot Project ◽  
Chemical Profiling ◽  
Counterfeit Medicines ◽  
Flame Ionization ◽  
Single Method ◽  
Solid Form

Gas chromatography (GC) is a gold standard technique used in forensic laboratories, including for the characterization of counterfeit medicines. When coupled simultaneously to flame ionization (FID) and mass detector (MS) allow the identification and quantification of medicines and drugs employing a single method, besides permitting the application of chemometric tools for forensic intelligence purposes. Here is presented a pilot project that developed and applied a qualitative method for the analysis of counterfeit medicines comprised by amphetamine-type stimulants and antidepressants, through a simple extraction procedure followed by GC-FID/MS analysis, with application of exploratory tools by Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA). The main purpose was to identify similarities between the all compounds detected in the irregular medicines allowing the traceability of illicit producers with the creation of a common data base. Through the analyses it was verified that different producers of counterfeit medicines labeled as Sibutramine, added a mixture of Caffeine and Benzocaine in their formulation, respecting the same ratio of 2.2:1. HCA was able to confirm these results, showing the presence of both falsifications in the same cluster, representing the best tool to identify similar characteristics among the samples – when compared to PCA. Other interesting finding was the use of Fluoxetine as a falsification of counterfeit medicines labeled as Sibutramine and Diethylpropion. Another seized sample labeled as “Nobesio Forte”, marketed as a mix of stimulants, showed only Caffeine and Lidocaine in its formulation. The pilot project applied primarily to 45 samples of counterfeit medicines containing amphetamine-type stimulants and antidepressants, showed the capability of perform the chemical profiling of counterfeit medicines in the solid form - powder, capsules and tablets. Further analysis can be performed for different types of medicines in solid form using the developed method, allowing the construction of a single database to perform the chemical profiling of counterfeit medicines, enabling the traceability of illicit producers.

scholarly journals Application of gas chromatography analysis to quality control of residual organic solvents in clopidogrel bisulphate

2014 ◽  
Vol 79 (10) ◽  
pp. 1279-1293 ◽  
Author(s):  
Aleksandar Pavlovic ◽  
Ljubisa Ignjatovic ◽  
Sasa Popov ◽  
Aleksandar Mladenovic ◽  
Igor Stankovic
Keyword(s):  
Degradation Products ◽  
Direct Injection ◽  
Principal Component ◽  
Process Variations ◽  
Hierarchical Cluster ◽  
Statistical Technique ◽  
Dimethyl Formamide ◽  
Chromatography Analysis ◽  
Flame Ionization ◽  
Gas Chromatographic Method

A direct-injection, split-mode capillary gas chromatographic procedure with a flame ionization detection is developed for the analysis of eight solvents used in the synthesis and purification of an anti-thrombotic drug clopidogrel bisulphate. The solvents analyzed were methanol, acetone, dichloromethane (DCM), 2-butanol, cyclohexane, toluene, acetic acid and N, N-dimethyl formamide (DMF). In addition, as a result of dehydration of 2-butanol during drying process, in clopidogrel bisulphate samples, significant amounts of 2-butanol dehydration products (1-butene, cis and trans isomers of 2-butene, 2,2'-oxydibutane and 1-(1-methylpropoxy)butane) may be detected. The content of each of these volatile products can be evaluated using the same gas-chromatographic method, with quantification based on the response factor established for the chromatographic peak of 2-butanol. For each solvent used in the process of clopidogrel bisulphate preparation, the procedure is validated for selectivity, linearity, recovery, precision, robustness, quantitation limit, and detection limit. All eight solvents plus five 2-butanol degradation products are fully separated. System suitability test is validated, and requirements are set. Based on a large number of result sets, retrospectively, from many different batches analyzed, conclusions were made about process variations and reliability and a lack of consistency was identified in the quality of the active substance from a particular producer source. Multivariate analysis was used as statistical technique to classify samples. From the analyzed set of 11 solvents, 6 of them were preselected based upon their occurrence in the samples and both Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were performed.

scholarly journals Seasonal variability of the essential oil of Hesperozygis ringens (Benth.) Epling.

2016 ◽  
Vol 76 (1) ◽  
pp. 176-184 ◽  
Author(s):  
C. G. Pinheiro ◽  
C. M. Machado ◽  
L. P. Amaral ◽  
D. T. Silva ◽  
C. A. A. Almeida ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Essential Oil ◽  
Native Species ◽  
Chemical Constituents ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Flame Ionization ◽  
Four Seasons ◽  
Three Samples

Abstract This study was developed to evaluate the effect of seasonality on the yield and chemical composition of the essential oil (EO) of Hesperozygis ringens (Benth.) Epling, a native species from the Brazilian Pampa. Leaves were collected from four specimens of a single population in each of the four seasons for a year and were extracted in triplicate by hydro-distillation for 2 hours. The yield of EO (% w/w) was calculated on fresh weight basis (FWB), and the 16 oil samples were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used as statistical tools to evaluate differences in chemical composition. The highest yields were obtained in autumn, spring and summer (2.32-4.38%), while the lowest yields were detected in winter, ranging from 1.15 to 1.91%. Oxygenated monoterpenoids were the predominant class of chemical constituents in the EO obtained in all seasons, showing the highest contents in autumn and summer, and pulegone was identified as a major compound, whose contents varied between 54.13 and 81.17%. The EO samples were divided into three chemical groups by HCA and PCA and were assigned to the same group, except for the three samples gathered in winter. The results showed a seasonal influence on the yield and chemical composition of the EO.

scholarly journals Assessment of diurnal variation in Ocimum sanctum Linn. by gas chromatographic fingerprint analysis coupled with chemometric methods

2018 ◽  
Vol 5 (3) ◽  
pp. 131-134 ◽  
Author(s):  
Nikunj Patel ◽  
Niranjan Kanaki ◽  
Vinit Movaliya
Keyword(s):  
Chemical Composition ◽  
Diurnal Variation ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Ocimum Sanctum ◽  
Chemical Compositions ◽  
Chemometric Methods ◽  
Flame Ionization ◽  
Ocimum Species ◽  
Significant Difference

Vast intra-specific variations, especially diurnal, geographical and seasonal, have been reported in the chemical composition of essential oils of Ocimum species. The study was conducted to assess diurnal variation in the chemical composition of the leaves of Ocimum sanctum. The leaf samples collected at different times of the day were analyzed by gas chromatography coupled with flame ionization detector (GC-FID). The chromatographic fingerprints of different leaf samples were analyzed by chemometric methods like principal component analysis and hierarchical cluster analysis. No significant difference was found in the chemical compositions of the leaf samples collected at different times of the day. The results lead to a conclusion that O. sanctum does not exhibit diurnal variation in its chemical composition, unlike O. gratissimum.

Quality evaluation of tugaksheeree samples by ATR-FTIR spectroscopy using multicomponent analysis

2020 ◽  
Vol 10 ◽  
Author(s):  
Nikunj D. Patel ◽  
Niranjan S. Kanaki
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Quality Evaluation ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Attenuated Total Reflectance ◽  
Chemometric Methods ◽  
Total Reflectance ◽  
Fingerprint Region ◽  
Ftir Technique

Background: Numerous Ayurvedic formulations contains tugaksheeree as key ingredient. Tugaksheereeis the starch gained from the rhizomes of two plants, Curcuma angustifoliaRoxb. (Zingiberaceae) and Marantaarundinacea (MA) Linn. (Marantaceae). Objective: The primary concerns in quality assessment of Tugaksheeree occur due to adulteration or substitution. Method: In current study, Fourier transform infrared (FTIR) technique with attenuated total reflectance (ATR) facility was used to evaluate tugaksheeree samples. Total 10 different samples were studied and transmittance mode was kept to record the spectra devoid of pellets of KBR. Further treatment was given with multi component tools by considering fingerprint region of the spectra. Multivariate analysis was performed by various chemometric methods. Result: Multi component methods like Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA)were used to discriminate the tugaksheeree samples using Minitab software. Conclusion: This method can be used as a tool to differentiate samples of tugaksheeree from its adulterants and substitutes.

scholarly journals Multivariate Statistical Approach for Nephrines in Women with Obesity

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1393
Author(s):  
Ralitsa Robeva ◽  
Miroslava Nedyalkova ◽  
Georgi Kirilov ◽  
Atanaska Elenkova ◽  
Sabina Zacharieva ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Data Analysis ◽  
Stress Response ◽  
Exploratory Data Analysis ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Obese Women ◽  
Exploratory Data

Catecholamines are physiological regulators of carbohydrate and lipid metabolism during stress, but their chronic influence on metabolic changes in obese patients is still not clarified. The present study aimed to establish the associations between the catecholamine metabolites and metabolic syndrome (MS) components in obese women as well as to reveal the possible hidden subgroups of patients through hierarchical cluster analysis and principal component analysis. The 24-h urine excretion of metanephrine and normetanephrine was investigated in 150 obese women (54 non diabetic without MS, 70 non-diabetic with MS and 26 with type 2 diabetes). The interrelations between carbohydrate disturbances, metabolic syndrome components and stress response hormones were studied. Exploratory data analysis was used to determine different patterns of similarities among the patients. Normetanephrine concentrations were significantly increased in postmenopausal patients and in women with morbid obesity, type 2 diabetes, and hypertension but not with prediabetes. Both metanephrine and normetanephrine levels were positively associated with glucose concentrations one hour after glucose load irrespectively of the insulin levels. The exploratory data analysis showed different risk subgroups among the investigated obese women. The development of predictive tools that include not only traditional metabolic risk factors, but also markers of stress response systems might help for specific risk estimation in obesity patients.

scholarly journals Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

2021 ◽  
Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki
Keyword(s):  
Ir Spectra ◽  
Forensic Toxicology ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Vitreous Humor ◽  
Attenuated Total Reflection ◽  
Glass Slides ◽  
Added Benefit ◽  
Ft Ir ◽  
Non Destructive

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract

scholarly journals A Methodology Based on FT-IR Data Combined with Random Forest Model to Generate Spectralprints for the Characterization of High-Quality Vinegars

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1411
Author(s):  
José Luis P. Calle ◽  
Marta Ferreiro-González ◽  
Ana Ruiz-Rodríguez ◽  
Gerardo F. Barbero ◽  
José Á. Álvarez ◽  
...  
Keyword(s):  
Random Forest ◽  
Raw Materials ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Raw Material ◽  
Support Vector ◽  
Protected Designation Of Origin ◽  
Ft Ir

Sherry wine vinegar is a Spanish gourmet product under Protected Designation of Origin (PDO). Before a vinegar can be labeled as Sherry vinegar, the product must meet certain requirements as established by its PDO, which, in this case, means that it has been produced following the traditional solera and criadera ageing system. The quality of the vinegar is determined by many factors such as the raw material, the acetification process or the aging system. For this reason, mainly producers, but also consumers, would benefit from the employment of effective analytical tools that allow precisely determining the origin and quality of vinegar. In the present study, a total of 48 Sherry vinegar samples manufactured from three different starting wines (Palomino Fino, Moscatel, and Pedro Ximénez wine) were analyzed by Fourier-transform infrared (FT-IR) spectroscopy. The spectroscopic data were combined with unsupervised exploratory techniques such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), as well as other nonparametric supervised techniques, namely, support vector machine (SVM) and random forest (RF), for the characterization of the samples. The HCA and PCA results present a clear grouping trend of the vinegar samples according to their raw materials. SVM in combination with leave-one-out cross-validation (LOOCV) successfully classified 100% of the samples, according to the type of wine used for their production. The RF method allowed selecting the most important variables to develop the characteristic fingerprint (“spectralprint”) of the vinegar samples according to their starting wine. Furthermore, the RF model reached 100% accuracy for both LOOCV and out-of-bag (OOB) sets.

scholarly journals Separation of Cultivars of Soybeans by Chemometric Methods Using Near Infrared Spectroscopy

2018 ◽  
Vol 10 (4) ◽  
pp. 351
Author(s):  
João S. Panero ◽  
Henrique E. B. da Silva ◽  
Pedro S. Panero ◽  
Oscar J. Smiderle ◽  
Francisco S. Panero ◽  
...  
Keyword(s):  
Spectral Data ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Relevant Information ◽  
Whole Grains ◽  
Signal Correction ◽  
Different Types ◽  
Linear Fit

Near Infrared (NIR) Spectroscopy technique combined with chemometrics methods were used to group and identify samples of different soy cultivars. Spectral data, collected in the range of 714 to 2500 nm (14000 to 4000 cm-1), were obtained from whole grains of four different soybean cultivars and were submitted to different types of pre-treatments. Chemometrics algorithms were applied to extract relevant information from the spectral data, to remove the anomalous samples and to group the samples. The best results were obtained considering the spectral range from 1900.6 to 2187.7 nm (5261.4 cm-1 to 4570.9 cm-1) and with spectral treatment using Multiplicative Signal Correction (MSC) + Baseline Correct (linear fit), what made it possible to the exploratory techniques Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) to separate the cultivars. Thus, the results demonstrate that NIR spectroscopy allied with de chemometrics techniques can provide a rapid, nondestructive and reliable method to distinguish different cultivars of soybeans.

scholarly journals Assessment of essential elements and chemical contaminants in thirteen fish species from the Bay Aratu, Bahia, Brasil

2016 ◽  
Vol 76 (4) ◽  
pp. 871-877 ◽  
Author(s):  
E. Silva ◽  
Z. C. V. Viana ◽  
N. F. A. Souza ◽  
M. G. A. Korn ◽  
V. L. C. S. Santos
Keyword(s):  
Fish Species ◽  
Inductively Coupled Plasma ◽  
Certified Reference Materials ◽  
Principal Component ◽  
Optical Emission ◽  
Hierarchical Cluster ◽  
Essential Elements ◽  
Emission Spectrometry ◽  
Oyster Tissue ◽  
National Agency

Abstract Concentrations of ten elements (Cd, Cr, Cu, Fe, Ni, Pb, Se, Sr, V and Zn) were determinate in muscle tissues of 13 fish species from Aratu Bay, Bahia, Brazil by inductively coupled plasma optical emission spectrometry. The accuracy and precision of our results were checked by using two certified reference materials: BCR-422 cod muscle and SRM 1566b oyster tissue. The average trace element concentrations in the fish species varied in the following ranges, in μg g–1: 0.03-0.8 for Cr; 2.0-33.7 for Cu, 2.4-135.1 for Fe, 1.6-25.6 for Se; 1.6-35.1 for Sr; and 2.8-40.5 for Zn. The Diaptereus rhombeus (carapeba) specie presented the highest concentrations of Se, Cu and Fe. Chromium and Se were present at levels above the limit of tolerance allowed by the National Agency of Sanitary Vigilance (ANVISA). The results were also evaluated using the multivariate analysis techniques: principal component analysis (PCA) and hierarchical cluster analysis (HCA).

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