Ventral Tegmental Area Glutamatergic Neurons Facilitated Emergence From Isoflurane Anesthesia Involves Excitation of Lateral Septum γ-Aminobutyric Acid-ergic Neurons in Mice.

BACKGROUND: Ventral tegmental area (VTA) glutamatergic neurons promote wakefulness in the sleep-wake cycle; however, their roles and neural circuit mechanisms during isoflurane (ISO) anesthesia remain unclear. METHODS: Fiber photometry and in vivo electrophysiology were used to observe the changes in neuronal or terminal activity during ISO anesthesia and arousal processes. Optogenetic and anesthesia behaviors were used to investigate the effects of VTA glutamatergic neurons and their projections to the lateral septum (LS) during ISO anesthesia and arousal. Anterograde and retrograde tracings were performed to identify the connections between VTA glutamatergic neurons and the LS. RESULTS: Population activity and firing rates of VTA glutamatergic neurons decreased during ISO anesthesia (ISO: 95% confidence interval [CI], 0.83-2.06 Spikes.s-1 vs wake: 95% CI, 3.53-7.83 Spikes.s-1; P =.0001; n = 34 from 4 mice). Optogenetic activation of VTA glutamatergic neurons reduced the burst-suppression ratio in electroencephalography (laser: 95% CI, 13.09%-28.76% vs pre: 95% CI, 52.85%-71.59%; P =.0009; n = 6) and facilitated emergence (ChR2: 95% CI, 343.3-388.0 seconds vs mCherry: 95% CI, 447.6-509.8 seconds; P < .0001; n = 11/12) from ISO anesthesia. VTA glutamatergic neurons monosynaptically innervated LS γ-aminobutyric acid (GABA)-ergic neurons. The activity of VTA glutamatergic terminals in the LS decreased during ISO anesthesia, and optogenetic activation of the VTA glutamatergic terminals in the LS facilitated emergence from ISO anesthesia. Furthermore, optogenetic activation of VTA glutamatergic terminals increased the firing rates of LS γ-aminobutyric acid-ergic (GABAergic) neurons (laser: 95% CI, 0.85-4.03 Spikes.s-1 vs pre: 95% CI, 0.24-0.78 Spikes.s-1; P =.008; n = 23 from 4 mice) during ISO anesthesia. CONCLUSIONS: VTA glutamatergic neurons facilitated emergence from ISO anesthesia involving excitation of LS GABAergic neurons.

Dysfunction of ventral tegmental area GABA neurons causes mania-like behavior.

The ventral tegmental area (VTA), an important source of dopamine, regulates goal- and reward-directed and social behaviors, wakefulness, and sleep. Hyperactivation of dopamine neurons generates behavioral pathologies. But any roles of non-dopamine VTA neurons in psychiatric illness have been little explored. Lesioning or chemogenetically inhibiting VTA GABAergic (VTAVgat) neurons generated persistent wakefulness with mania-like qualities: locomotor activity was increased; sensitivity to D-amphetamine was heightened; immobility times decreased on the tail suspension and forced swim tests; and sucrose preference increased. Furthermore, after sleep deprivation, mice with lesioned VTAVgat neurons did not catch up on lost sleep, even though they were starting from a sleep-deprived baseline, suggesting that sleep homeostasis was bypassed. The mania-like behaviors, including the sleep loss, were reversed by valproate, and re-emerged when treatment was stopped. Lithium salts and lamotrigine, however, had no effect. Low doses of diazepam partially reduced the hyperlocomotion and fully recovered the immobility time during tail suspension. The mania like-behaviors mostly depended on dopamine, because giving D1/D2/D3 receptor antagonists reduced these behaviors, but also partially on VTAVgat projections to the lateral hypothalamus (LH). Optically or chemogenetically inhibiting VTAVgat terminals in the LH elevated locomotion and decreased immobility time during the tail suspension and forced swimming tests. VTAVgat neurons help set an animal's (and perhaps human's) mental and physical activity levels. Inputs inhibiting VTAVgat neurons intensify wakefulness (increased activity, enhanced alertness and motivation), qualities useful for acute survival. In the extreme, however, decreased or failed inhibition from VTAVgat neurons produces mania-like qualities (hyperactivity, hedonia, decreased sleep).

Current applications of platelet gels in wound healing-A review.

Human platelets play important roles in several physiologic and pathologic processes. Platelet concentrates are activated with thrombin or calcium, resulting in a viscous coagulum (platelet gel [PG]), composed of 95% platelets at least. PG is increasingly used for the treatment of a variety of soft and hard tissue defects, most notably in the management of chronic non-healing wounds. During wound healing, platelets not only play a critical role in primary hemostasis and thrombosis, but also release growth factors and cytokines to promote tissue regeneration, enhance collagen synthesis, and trigger an immune response. This review addresses a variety of aspects relevant to the functions of well-known platelet growth factors, animal and clinical studies of PG in the last decade, and different sources of platelets for PG. PG is used for non-healing chronic wounds, such as oral ulcerations related to epidermolysis bullosa and chronic graft-versus-host disease, for those, the traditional treatment effect is poor. PG maybe provide a new therapeutic direction for these diseases. Nevertheless, some uncertainty is present, the number of clinical studies is not enough. Hence, randomized controlled trials are still required to study the potential of the use of PG in the near future.

Carboxylation modified meso-porous carbon aerogel templated by ionic liquid for solid-phase microextraction of trace tetracyclines residues using HPLC with UV detection.

A carbon aerogel composite templated and catalyzed by ionic liquid was fabricated to obtain a meso-porous and cross-linked structure while avoiding the freeze and supercritical drying. It was then carboxylated to obtain favorable surface groups. The easily prepared material displayed excellent extraction effect of six tetracyclines (TCs) compared to the non-carboxylated carbon aerogel. A direct immersion solid-phase microextraction method to determine six TCs in aqueous samples was developed coupling with high-performance liquid chromatography (HPLC) with UV-Vis detector set at 355 nm. The experimental parameters affecting the analytical performance of this method, including sample pH, ionic strength, extraction and desorption time, extraction volume, and temperature, were optimized. Adsorption kinetics and thermodynamics models were used to clarify the extraction mechanism. Under the optimized conditions, this method has a wide linear range of 2-1000 µg L-1, low limits of detection of 0.36-0.71 µg L-1, repeatability of 1.85-10.96%, and reproducibility of 4.92-13.47% for six TCs. The method was successfully applied to detect TC residues in egg and poultry farm wastewater samples.

Label-free analytical performances of a peptide-based QCM biosensor for trypsin.

A label-free biosensor was fabricated for the detection of trypsin by using a peptide-functionalized quartz crystal microbalance gold electrode. The synthetized peptide chains were immobilized tightly on the QCM electrode via a self-assembly method, which formed a thin and approximate rigid layer of peptides. The detection signal was achieved by calculating the mass changes on the QCM electrode because the peptide chains could be specifically cleaved in the carboxyl terminuses of arginine and lysine by trypsin. When gold nanoparticles were coupled to the peptide chains, the sensing signal would be amplified 10.9 times. Furthermore, the sensor interface shows a lower resonance resistance change when the peptide chain is immobilized horizontally. Independent detections in parallel on different electrodes have a wide linear range. Under the optimum conditions, the signal-amplified biosensor allowed the measurement of trypsin over the range of 0-750 ng mL-1 with a detection limit of 8.6 ng mL-1. Moreover, for screening the inhibitor of trypsin, the IC50 values were obtained to be 1.85 µg mL-1 for benzamidine hydrochloride and 20.5 ng mL-1 for the inhibitor from soybean.

An in vitro study of coagulation properties in refrigerated whole blood and reconstituted whole blood.

OBJECTIVE: Fresh whole blood (WB) has been used in military applications and cardiac surgery. We undertook a study of the coagulation properties of refrigerated WB stored for 21 days and compared them with the properties of reconstituted WB. STUDY DESIGN AND METHODS: Ten WB units were obtained from healthy volunteer donors and stored at 4 ± 2°C. Samples were obtained on Days 1, 2, 4, 6, 8, 10, 14 and 21 from the WB units. Ten units of reconstituted WB were prepared with a ratio of red cells, platelets and plasma of 1:1:1. Tests included complete blood count, electrolyte, routine coagulation, blood coagulation factor and thromboelastography. RESULTS: There was a progressive decline in Hb, WBC, PLT, sodium and coagulation factors but a progressive increase in APTT, PT and potassium in WB. The concentrations of factor (F)V and FVIII as well as FII and FX of WB were higher before Days 4, 2, 8 and 14, respectively, compared with the concentrations of reconstituted WB. The concentrations of FVII, FIX, FXI and FXII in WB were found to be equal to or higher than those in reconstituted WB throughout the course of 21 days. TEG variables in all WB units were normal throughout the course of 10 days. The mean PT and APTT of WB were lower than those of reconstituted WB before Days 14 and 10, respectively. CONCLUSION: This study suggests that the coagulation properties of refrigerated WB were equal to or superior to those of reconstituted WB for a minimum of 10 days.

A Novel Photoelectrochemical Biosensor for Tyrosinase and Thrombin Detection.

A novel photoelectrochemical biosensor for step-by-step assay of tyrosinase and thrombin was fabricated based on the specific interactions between the designed peptide and the target enzymes. A peptide chain with a special sequence which contains a positively charged lysine-labeled terminal, tyrosine at the other end and a cleavage site recognized by thrombin between them was designed. The designed peptide can be fixed on surface of the CdTe quantum dots (QDs)-modified indium-tin oxide (ITO) electrode through electrostatic attraction to construct the photoelectrochemical biosensor. The tyrosinase target can catalyze the oxidization of tyrosine by oxygen into ortho-benzoquinone residues, which results in a decrease in the sensor photocurrent. Subsequently, the cleavage site could be recognized and cut off by another thrombin target, restoring the sensor photocurrent. The decrease or increase of photocurrent in the sensor enables us to assay tyrosinase and thrombin. Thus, the detection of tyrosinase and thrombin can be achieved in the linear range from 2.6 to 32 µg/mL and from 4.5 to 100 µg/mL with detection limits of 1.5 µg/mL and 1.9 µg/mL, respectively. Most importantly, this strategy shall allow us to detect different classes of enzymes simultaneously by designing various enzyme-specific peptide substrates.

Occurrence of decabromodiphenyl ethane in captive Chinese alligators (Alligator sinensis) from China.

Decabromodiphenyl ethane (DBDPE), a replacement for decabromodiphenyl ether (deca-BDE), was investigated in captive Chinese alligators from China. DBDPE was detected in adult tissues, neonates and eggs of Chinese alligators with concentrations ranging from 4.74-192, 0.24-1.94, and 0.01-0.51 ng g(-1) lipid weight, respectively. Compared to PBDEs and PCBs, DBDPE contamination was limited in Chinese alligators. Additionally, DBDPE concentrations in adult muscles were one to three orders of magnitude higher than those in neonates and eggs, suggesting the limited maternal transfer potential of DBDPE in Chinese alligators. This is the first study to report the occurrence of DBDPE in Chinese alligators.

Nalbuphine in Pediatric Emergence Agitation Following Cochlear Implantation: A Randomized Trial.

Background: To investigate the effects of nalbuphine on emergency agitation (EA), which affects up to 80% of the children following otolaryngology procedures, in children undergoing cochlear implantation. Methods: A prospective double-blinded randomized controlled clinical trial was conducted between November 2020 and October 2022. Eligible children, aged 6 months to 3 years old, were randomly assigned to either 0.1 mg/kg, 0.15 mg/kg, 0.2 mg/kg nalbuphine or 0.9% saline groups. EA was defined by the Pediatric Anesthesia Emergence Delirium (PAED) score ≥10. Extubation time, post-anesthesia care unit (PACU) length of stay, severe EA (PAED ≥ 15), peak PAED score, the Faces, Legs, Activity, Cry, and Consolability (FLACC) scale, Ramsay sedation score, and adverse events were also recorded. Results: A total of 104 children were enrolled, with 26 children in each group. Nalbuphine significantly reduced the EA occurrence from 73.1% in the saline group to 38.5%, 30.8%, and 26.9% in the 0.1 mg/kg, 0.15 mg/kg, and 0.2 mg/kg nalbuphine groups, respectively (P < 0.001), without affecting the extubation time and PACU length of stay. More children (34.6%) in the 0.9% saline group experienced severe EA. Higher dose nalbuphine (0.15 mg/kg, 0.2 mg/kg) showed lower peak PAED score, better analgesia and sedation effect compared with 0.1 mg/kg nalbuphine and saline groups. However, 0.2mg/kg nalbuphine caused undesired over-sedation in two (7.7%) children. No other adverse events were reported. Conclusion: Young children undergoing cochlear implantation surgery were at a high risk of EA and postoperative pain, while 0.2 mg/kg nalbuphine might be an ideal candidate for EA and pain prevention when used under close monitoring. Trial Registration: ChiCTR2000040407.

Evaluation of stored red blood cell quality after washing using immune indices.

Washed red blood cells (RBCs) can be used to treat immune-related diseases. However, whether the washing process changes the quality of RBCs and affects the curative effect of transfusion therapy remains unclear. We retrospectively analysed the clinical data of patients who received blood transfusion. The physiological and biochemical parameters of RBCs were tested on an automated haematology-biochemical analyser. CD47 and phosphatidylserine (PS) plasma membrane expression were analysed using flow cytometry. Morphological changes in RBCs were observed using scanning electron microscopy. The results showed that the curative effect on patients who received washed RBCs was weaker than that on those who received non-washed RBCs. Physiological and biochemical parameters of RBCs were not significantly different. RBC immune indices changed significantly after washing. The expression of "don't eat me" signals was weakened, whereas the intensity of "eat me" signals was enhanced. This study suggests that the current use of physiological and biochemical parameters as indicators to evaluate the quality of RBCs may not be comprehensive and that evaluation of the real status of RBCs requires other effective parameters. Immune molecules in RBCs are expected to become supplementary markers for evaluating RBC quality.

Dysfunction of astrocytic glycophagy exacerbates reperfusion injury in ischemic stroke.

Glycophagy has evolved from an alternative glycogen degradation pathway into a multifaceted pivot to regulate cellular metabolic hemostasis in peripheral tissues. However, the pattern of glycophagy in the brain and its potential therapeutic impact on ischemic stroke remain unknown. Here, we observed that the dysfunction of astrocytic glycophagy was caused by the downregulation of the GABA type A receptor-associated protein like 1 (GABARAPL1) during reperfusion in ischemic stroke patients and mice. PI3K-Akt pathway activation is involved in driving GABARAPL1 downregulation during cerebral reperfusion. Moreover, glycophagy dysfunction-induced glucosamine deficiency suppresses the nuclear translocation of specificity protein 1 and TATA binding protein, the transcription factors for GABARAPL1, by decreasing their O-GlcNAcylation levels, and accordingly feedback inhibits GABARAPL1 in astrocytes during reperfusion. Restoring astrocytic glycophagy by overexpressing GABARAPL1 decreases DNA damage and oxidative injury in astrocytes and improves the survival of surrounding neurons during reperfusion. In addition, a hypocaloric diet in the acute phase after cerebral reperfusion can enhance astrocytic glycophagic flux and accelerate neurological recovery. In summary, glycophagy in the brain links autophagy, metabolism, and epigenetics together, and glycophagy dysfunction exacerbates reperfusion injury after ischemic stroke.

A theophylline quartz crystal microbalance biosensor based on recognition of RNA aptamer and amplification of signal.

A quartz crystal microbalance (QCM) biosensor for theophylline was developed by recognition of RNA aptamer and gold nanoparticle amplification technique. Firstly, a designed small single-stranded RNA, RNA1, was immobilized onto the QCM electrode through a thiol linker. Then, the complementary stranded RNA2, which can combine with RNA1 to form a double-stranded RNA with a recognition unit of theophylline, could be self-assembled on the QCM electrode surface through a hybrid reaction in the presence of theophylline. The recognition process could cause a frequency change of QCM to give the signal related to theophylline. When RNA2 was tethered to gold nanoparticles, the signal could be amplified to further enhance the sensitivity of the designed sensor. Under the optimal conditions, the QCM-based biosensor showed excellent sensitivity (limit of detection, 8.2 nM) and specificity with a dissociation constant of Kd = 5.26 × 10(-7) M. The sensor can be used to quantitatively detect theophylline in serum, suggesting that it can be applied in complex biological samples.

Direct electrochemistry of hemoglobin at a graphene gold nanoparticle composite film for nitric oxide biosensing.

A simple two-step method was employed for preparing nano-sized gold nanoparticles-graphene composite to construct a GNPs-GR-SDS modified electrode. Hemoglobin (Hb) was successfully immobilized on the surface of a basal plane graphite (BPG) electrode through a simple dropping technique. Direct electrochemistry and electrocatalysis of the hemoglobin-modified electrode was investigated. The as-prepared composites showed an obvious promotion of the direct electro-transfer between hemoglobin and the electrode. A couple of well-defined and quasi-reversible Hb CV peaks can be observed in a phosphate buffer solution (pH 7.0). The separation of anodic and cathodic peak potentials is 81 mV, indicating a fast electron transfer reaction. The experimental results also clarified that the immobilized Hb retained its biological activity for the catalysis toward NO. The biosensor showed high sensitivity and fast response upon the addition of NO, under the conditions of pH 7.0, potential -0.82 V. The time to reach the stable-state current was less than 3 s, and the linear response range of NO was 0.72-7.92 µM, with a correlation coefficient of 0.9991.

Recyclable magnetic Fe3O4@C for methylene blue removal under microwave-induced reaction system.

The reclamation and removal of organic pollutants are difficult issues of world concern. In this study, a microwave-induced reaction system (MIRS) is applied to synthesize the multifunctional composite of Fe3O4@C, which is employed to adsorb, separate and catalytic oxide the typical organic dye of methylene blue (MB). SEM, TEM, VSM, XPS, pHpzc, and N2 adsorption performances are carried out to characterize the Fe3O4@C. Results show that the Fe3O4@C mainly consists of activated Fe-O-C microspheres, which possess plentiful mesopore and macropore structures on surfaces. Batch adsorption experiments were carried out by varying key reaction conditions to optimize these. The maximum adsorption capacity of MB onto the Fe3O4@C was 305.0 mg g-1 in 120 min, at pH 10, and at a temperature of 323 K. MIRS was also assisted to regenerate the spent Fe3O4@C which presented good regeneration efficiency by sustaining 16 regeneration cycles without any oxidizing agent. SEM images and FTIR spectrum verified that MB would translate into greater or smaller-sized carbon microspheres. What's more, the adsorption of MB onto both initial and the 16th regenerated Fe3O4@C obeyed the Langmuir isotherm model and followed the pseudo-second-order adsorption kinetics, indicating the adsorptive stability after regeneration. In this study, the Fe3O4@C combined with MIRS may be one innovative strategy for organic pollutants' complete removal in the future.

Differences in the EEG Power Spectrum and Cross-Frequency Coupling Patterns between Young and Elderly Patients during Sevoflurane Anesthesia.

Electroencephalography (EEG) is widely used for monitoring the depth of anesthesia in surgical patients. Distinguishing age-related EEG features under general anesthesia will help to optimize anesthetic depth monitoring during surgery for elderly patients. This retrospective cohort study included 41 patients aged from 18 to 79 years undergoing noncardiac surgery under general anesthesia. We compared the power spectral signatures and phase-amplitude coupling patterns of the young and elderly groups under baseline and surgical anesthetic depth. General anesthesia by sevoflurane significantly increased the spectral power of delta, theta, alpha, and beta bands and strengthened the cross-frequency coupling both in young and elderly patients. However, the variation in EEG power spectral density and the modulation of alpha amplitudes on delta phases was relatively weaker in elderly patients. In conclusion, the EEG under general anesthesia using sevoflurane exhibited similar dynamic features between young and elderly patients, and the weakened alteration of spectral power and cross-frequency coupling patterns could be utilized to precisely quantify the depth of anesthesia in elderly patients.

Percutaneous cortical bone trajectory screw fixation versus traditional open pedicle screw fixation for type A thoracolumbar fractures without neurological deficit.

Retrospective matched-cohort comparative study. Cortical bone trajectory screw (CBT) technique is a new insertion technique in terms of fixation strength and less invasiveness. The purposes of this study were to compare the clinical and radiological outcomes of percutaneous CBT fixation (PCBT) with traditional open posterior pedicle screw fixation (OPPS) technique. Between September 2019 and October 2020, patients undergoing posterior stabilization were matched for age, sex, diagnosis, fractured level, and AO classification. 24 control patients with OPPS were identified and appropriately matched to 24 consecutive patients with PCBT technique. Clinical outcomes and radiographic assessments including vertebral wedge angle (VWA) and sagittal index were recorded and compared between the two groups. Incision length, intraoperative blood loss and hospital stay in the PCBT group were significantly better than the OPPS group (P < 0.05). The VAS scores 5 days after operation for PCBT patients were significantly lower than those for OPPS patients (P = 0.003), but these differences lost significance at last follow-up. There was no significant difference in VWA and sagittal index between OPPS and PCBT group (P > 0.05). While no complications were noted in the PCBT group, there were four cases with complications in the traditional OPPS group. The present study showed that PCBT is a safe and feasible method for the treatment of thoracolumbar fractures without neurological deficits. This new surgical treatment was more minimally invasive, yet yielded equivalent or superior clinical and radiographic outcomes compared to the traditional open pedicle screw fixation surgery.

Quartz crystal microbalance aptasensor for sensitive detection of mercury(II) based on signal amplification with gold nanoparticles.

We show that a short mercury-specific aptamer (MSA) along with gold nanoparticles (Au-NPs) can be used to determine Hg(II) ion by a combination of a QCM-based sensor and a flow system. The MSA binds specifically to Hg(II), and the Au-NPs can amplify the signal to enhance sensitivity. Specifically, the short thiolated MSAs are immobilized on the surface of the QCM as the capture probe, and the MSAs are linked to the Au-NPs as the linking probe. The two components can form a sandwich structure of the T-Hg(II)-T type in the presence of Hg(II) ions. This leads to change in the mass on the QCM and a change in the resonance frequency. Hg(II) can be determined with a detection limit of 0.24 ± 0.06 nM which is better by three orders of magnitude than previous methods. The sensor can be regenerated by disrupting the T-Hg(II)-T base pairs with a solution of cysteine.

Electroencephalogram Features of Perioperative Neurocognitive Disorders in Elderly Patients: A Narrative Review of the Clinical Literature.

Postoperative neurocognitive disorder (PND) is a common postoperative complication, particularly in older patients. Electroencephalogram (EEG) monitoring, a non-invasive technique with a high spatial-temporal resolution, can accurately characterize the dynamic changes in brain function during the perioperative period. Current clinical studies have confirmed that the power density of alpha oscillation during general anesthesia decreased with age, which was considered to be associated with increased susceptibility to PND in the elderly. However, evidence on whether general anesthesia under EEG guidance results in a lower morbidity of PND is still contradictory. This is one of the reasons that common indicators of the depth of anesthesia were limitedly derived from EEG signals in the frontal lobe. The variation of multi-channel EEG features during the perioperative period has the potential to highlight the occult structural and functional abnormalities of the subcortical-cortical neurocircuit. Therefore, we present a review of the application of multi-channel EEG monitoring to predict the incidence of PND in older patients. The data confirmed that the abnormal variation in EEG power and functional connectivity between distant brain regions was closely related to the incidence and long-term poor outcomes of PND in older adults.

Efficient Reduction of Cr(VI) with Carbon Quantum Dots.

Hexavalent chromium (Cr(VI)) pollution is a global problem, and the reduction of highly toxic Cr(VI) to less toxic Cr(III) is considered to be an effective method to address Cr(VI) pollution. In this study, low-toxicity carbon quantum dots (CQDs) were used to reduce Cr(VI) in wastewater. The results show that CQDs can directly reduce Cr(VI) at pH 2 and can achieve a reduction efficiency of 94% within 120 min. It is observed that under pH higher than 2, CQDs can activate peroxymonosulfate (PMS) to produce reactive oxygen species (ROS) for the reduction of Cr(VI) and the reduction efficiency can reach 99% within 120 min even under neutral conditions. The investigation of the mechanism shows that the hydroxyl groups on the surface of CQDs can be directly oxidized by Cr(VI) because of the higher redox potential of Cr(VI) at pH 2. As the pH increases, the carbonyl groups on the surface of CQDs can activate PMS to generate ROS, O2 •-, and 1O2, which result in Cr(VI) being reduced. To facilitate the practical application of CQDs, the treatment of Cr(VI) in real water samples by CQDs was simulated and the method reduced Cr(VI) from an initial concentration of 5 mg/L to only 8 µg/L in 150 min, which is below the California water quality standard of 10 µg/L. The study provides a new method for the removal of Cr(VI) from wastewater and a theoretical basis for practical application.

In Situ Synthetic ZIF-8/Carbon Aerogel Composites as Solid-Phase Microextraction Coating for the Detection of Phthalic Acid Esters in Water Samples.

In this study, a hybrid composite featuring zeolitic imidazolate framework-8/carbon aerogel (ZIF-8/CA) was synthesized via in situ nucleation and growth of ZIF-8 nanoparticles inside carbon aerogels. The novel material was used as the solid-phase microextraction (SPME) coating for the five phthalic acid esters (PAEs) detection by coupling with a gas chromatography-flame ionization detector (GC-FID). Compared with bare carbon aerogel, the ZIF-8/CA presented the best performance, which is attributed to the unique advantages between the high surface area of CA and high hydrophobic properties, the thermal stability of ZIF-8, and their synergistic adsorption effects, such as molecular penetration, hydrogen bond, and π-π stacking interactions. Under the optimized conditions, the as-proposed ZIF-8/CA fiber provided a wide linearity range from 0.2 to 1000 µg L-1 and a low detection limit of 0.17-0.48 µg L-1 for PAEs analysis. The intra-day and inter-day of signal fiber and the fiber-fiber relative standard deviations were observed in the ranges of 3.50-8.16%, 5.02-10.57%, and 5.66-12.11%, respectively. The method was applied to the determination of five PAEs in plastic bottled and river water samples.