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A rapid and simple analytical method based on matrix solid-phase dispersion combined with liquid chromatography coupled with tandem mass spectrometry has been developed by using bamboo charcoal as a dispersive adsorbent to simultaneously determine tetrabromobisphenol A (TBBPA) and hexabromocyclododecane diastereoisomers (HBCDs) in soil. The factors influencing the performance of the proposed method were investigated and optimized in detail, and the matrix effects were evaluated. Under optimum conditions, the proposed method showed good linearity within the range of 0.8–80 ng g−1 and limits of detection of 4–75 pg g−1 (S/N = 3). The satisfactory recoveries of TBBPA ranging from 72.8% to 92.5% and HBCDs ranging from 76.8% to 102.2% were obtained with relatively standard deviation (RSD) ranging from 3.4% to 9.8%. The proposed method has been successfully applied to analyze TBBPA and HBCDs in actual soil samples from the Yellow River Delta in China.

Open access
Acta Chromatographica
Authors:
Long Wang
,
Yuan-Yuan Jiang
,
Li Zhang
,
Tao Wang
,
Rui-Wu Yang
,
Chun-Bang Ding
,
Xiao-Li Wang
, and
Yong-Hong Zhou

A high-performance liquid chromatography (HPLC) method has been developed for the simultaneous identification and quantification of active compounds (cryptotanshinone, dihydrotanshinone I, tanshinone IIA, tanshinone I, salvianolic acid A, salvianolic acid B, protocatechuic aldehyde, and rosmarinic acid) contained in traditional Chinese folk medicine Salvia przewalskii Maxim. The herb samples (including wild, cultivated, and yin pian) from fourteen main regions were investigated. Chromatographic separation was performed on an Agilent Eclipse XDB-C18 reserved-phase column (250 mm × 4.6 mm i.d., 5 μm) using gradient elution with water-formic acid (99.9: 0.1, v/v) and acetonitrile at a flow rate of 0.8 mL min−1, an operating temperature of 30 °C, and a wavelength of 275 nm. Similarity analysis (SA), principal component analysis (PCA), and hierarchical cluster analysis (HCA) were used to analyze the data based on fingerprints. For fingerprint analysis, 27 peaks were selected as the common peaks to evaluate the similarities among different samples. The results of SA showed that the method permits to obtain desired linearity, precision, accuracy, and recovery. All samples were divided into three categories by PCA and HCA, and the concentration of the eight bioactive compounds varied significantly from different regions. It was demonstrated that chromatographic fingerprinting by HPLC combined with the simultaneous determination of eight bioactive compounds was a helpful method for the quality control of S. przewalskii.

Open access

A simple and rapid high-performance liquid chromatographic (HPLC) method was established for simultaneous determination of butorphanol tartrate and ondansetron hydrochloride in analgesic mixture samples used for patient-controlled analgesia (PCA). The separation of butorphanol tartrate and ondansetron hydrochloride in PCA solution was carried out on phenomenex C18 column (4.6 mm × 150 mm, 5 μm) using 50 mM sodium acetate (pH 4.0) buffer and acetonitrile (72:28, v/v). Flow rate was 1.0 mL min−1 with a column temperature of 30 °C, and detection wavelength was carried out at 280 nm and 306 nm. Validation of the method was made in terms of specificity, linearity, accuracy, and intra- and inter-day precision, as well as quantification and detection limits. The developed method was successfully used to evaluate the chemical stability of butorphanol tartrate and ondansetron hydrochloride in analgesic mixtures at the usual concentration used for PCA.

Open access

Summary

An efficient ionic liquid-based microwave-assisted (IL-MAE) method has been developed for extraction of dehydrocavidine from Corydalis saxicola Bunting (C. saxicola) for subsequent rapid analysis by high-performance liquid chromatography (HPLC). The yield of dehydrocavidine reached 9.446 mg g−1 within 10 min under the optimum IL-MAE conditions (1.5 mol L−1 [hmim]Br as extraction solvent, liquid-to-solid ratio 20:1 (mL:g), and extraction temperature 70°C). Compared with conventional procedures, the proposed IL-MAE method has many advantages, for example high extraction yield, short extraction time, low solvent consumption, no use of volatile organic solvents, and no further sample clean-up before HPLC analysis. The method was validated for limit of detection (LOD) and quantification (LOQ), linearity, precision, recovery, and reproducibility. The calibration range was 5.0–200 mg L−1 and the correlation coefficient, r, was 0.9996. The LOD and LOQ were 0.035 and 0.12 mg L−1, respectively. The relative standard deviations of intra-day and inter-day assays were below 2.6% and 6.5%, respectively. Recovery was between 93.8% and 109.3% with RSD values below 5.0%. The method can be used for rapid and effective extraction and analysis of active components from medicinal plants.

Open access

Abstract

Anisodus tanguticus (Maxim.) Pascher is an important Tibetan folk medicine and the source of tropane alkaloids (TAs) grown in Qinghai-Tibet Plateau. There are marked differences in quality of A. tanguticus from geographic areas. The aim of present research was to establish a method for the quantitative analysis of TAs coupled with chemometrics analysis to trace geographical origins. Qualitative analysis of TAs in A. tanguticus was carried out using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and quantitative analysis of TAs in different plant organs from different geographical origin was achieved. Contents of TAs were subjected to the principal component analysis, and orthogonal partial least-squares discriminant analysis. The contents of the three marker compounds (anisodamine, anisodine and atropine) in the roots and acrial parts of A. tanguticus were positive correlated and varied significantly from different geographical origins. Principal component analysis, and orthogonal partial least-squares discriminant analysis results showed excellent discrimination between different geographical origin of A. tanguticus. This study could provide comprehensive evaluation and further utilization of A. tanguticus resources.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Lin-Quan Liao
,
Hong-Jian Wei
,
Ji-Zhen Li
,
Xue-Zhong Fan
,
Ya Zheng
,
Yue-Ping Ji
,
Xiao-Long Fu
,
Ya-Jun Zhang
, and
Fang-Li Liu

Abstract

The compatibility of poly(3-nitromethyl-3-methyloxetane) (PNIMMO) with some energetic materials are studied by using pressure DSC method in detail. Cyclotetramethylenetetranitroamine (HMX), cyclotrimethylenetrinitramine (RDX), nitrocellulose (NC), nitroglycerine (NG), N-nitrodihydroxyethylaminedinitrate (DINA), and aluminum powder (Al) are used as common energetic materials, and 3,4-dinitrofurzanfuroxan (DNTF), 1,3,3-trinitroazetidine (TNAZ), hexanitrohexazaisowurtzitane (CL-20), 4,6-dinitro-5,7-diaminobenzenfuroxan (CL-14), 1,1-diamino-2,2-dinitroethylene (DADNE), and 4-amino-5-nitro-1,2,3-triazole (ANTZ) are used as new energetic materials. The results show that the binary systems of PNIMMO with HMX, RDX, NC, NG, DINA, Al, CL-14 and DADNE are compatible, with TNAZ, CL-20 and ANTZ are slightly sensitive, and with DNTF is sensitive.

Open access

A reliable isotope dilution method for the determination of chloramphenicol (CAP) in drinking water was developed by using an evaporation preparative step. Each sample was monitored by ultrahigh-pressure liquid chromatography (UHPLC) coupled to tandem mass spectrometry (MS/MS) using an electrospray ionization interface (ESI) in negative ion modes. Recoveries of spiked samples were in the range from 93.2% to 95.7% with intra-day relative standard deviation lower than 6.7% and inter-day relative standard deviation lower than 8.2%. Limit of quantification (LOD) was 0.002 ng/mL. The developed method was successfully applied to the analysis of CAP in drinking water of Shannan region of Tibet.

Open access

Abstract

Background

Increasing research has examined the factors related to smartphone use disorder. However, limited research has explored its neural basis.

Aims

We aimed to examine the relationship between the topology of the resting-state electroencephalography (rs-EEG) brain network and smartphone use disorder using minimum spanning tree analysis. Furthermore, we examined how negative emotions mediate this relationship.

Methods

This study included 113 young, healthy adults (mean age = 20.87 years, 46.9% males).

Results

The results showed that the alpha- and delta-band kappas and delta-band leaf fraction were positively correlated with smartphone use disorder. In contrast, the alpha-band diameter was negatively correlated with smartphone use disorder. Negative emotions fully mediated the relationship between alpha-band kappa and alpha-band diameter and smartphone use disorder. Furthermore, negative emotions partially mediated the relationship between delta-band kappa and smartphone use disorder. The findings suggest that excessive scale-free alpha- and delta-band brain networks contribute to the emergence of smartphone use disorder. In addition, the findings also demonstrate that negative emotions and smartphone use disorder share the same neural basis. Negative emotions play a mediating role in the association between topological deviations and smartphone use disorder.

Discussion

To the best of our knowledge, this is the first study to examine the neural basis of smartphone use disorder from the perspective of the topology of the rs-EEG brain network. Therefore, neuromodulation may be a potential intervention for smartphone use disorder.

Open access
Journal of Behavioral Addictions
Authors:
Shan-Shan Ma
,
Chiang-Shan R. Li
,
Sheng Zhang
,
Patrick D. Worhunsky
,
Nan Zhou
,
Jin-Tao Zhang
,
Lu Liu
,
Yuan-Wei Yao
, and
Xiao-Yi Fang

Abstract

Background and aims

Deficits in cognitive control represent a core feature of addiction. Internet Gaming Disorder (IGD) offers an ideal model to study the mechanisms underlying cognitive control deficits in addiction, eliminating the confounding effects of substance use. Studies have reported behavioral and neural deficits in reactive control in IGD, but it remains unclear whether individuals with IGD are compromised in proactive control or behavioral adjustment by learning from the changing contexts.

Methods

Here, fMRI data of 21 male young adults with IGD and 21 matched healthy controls (HC) were collected during a stop-signal task. We employed group independent component analysis to investigate group differences in temporally coherent, large-scale functional network activities during post-error slowing, the typical type of behavioral adjustments. We also employed a Bayesian belief model to quantify the trial-by-trial learning of the likelihood of stop signal – P(Stop) – a broader process underlying behavioral adjustment, and identified the alterations in functional network responses to P(Stop).

Results

The results showed diminished engagement of the fronto-parietal network during post-error slowing, and weaker activity in the ventral attention and anterior default mode network in response to P(Stop) in IGD relative to HC.

Discussion and conclusions

These results add to the literatures by suggesting deficits in updating and anticipating conflicts as well as in behavioral adjustment according to contextual information in individuals with IGD.

Open access
Acta Chromatographica
Authors:
Hao-ran Dai
,
Ya-hui Hu
,
Jia-yi Long
,
Ying Xia
,
Hong-li Guo
,
Jing Xu
,
Xuan-sheng Ding
,
Jing Chen
,
Xiao-peng Lu
, and
Feng Chen

Abstract

Perampanel (PER) is the first clinically available selective antagonist of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor approved globally for the treatment of epilepsy. Studies have recently underlined the significant association between dose-exposure-effect-adverse events of PER in patients with epilepsy, so the therapeutic drug monitoring (TDM) of PER is critical in clinical practices, especially for pediatric patients with drug-resistant epilepsy. Due to several limits in previous published analytical methods, herein, we describe the development and validation of a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method for monitoring PER in human plasma samples. Protein precipitation method by acetonitrile containing PER-d5 as internal standard was applied for the sample clean-up. Formic acid (FA, 0.2 mM) in both aqueous water and acetonitrile were used as the mobile phases and the analyte was separated by an isocratic elution. Qualification and quantification were performed under positive electrospray ionization (ESI) mode using the m/z 350.3 → 219.1 and 355.3 → 220.0 ions pairs transitions for PER and PER-d5, respectively. Potential co-medicated anti-seizure medications (ASMs) have no interference to the analysis. Calibration curves were linear in the concentration range of 1.00–2,000 ng mL−1 for PER. The intra- and inter-batch precision, accuracy, recovery, dilution integrity, and stability of the method were all within the acceptable criteria and no matrix effect or carryover was found. This method was then successfully implemented on the TDM of PER in Chinese children with drug-resistant epilepsy. We firstly confirmed the apparent inter- and intra-individual PER concentration variabilities and potential drug-drug interactions between PER and several concomitant ASMs occurred in Chinese pediatric patients, which were also in line with previous studies in patients of other race.

Open access