Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 248
Filtrar
1.
Talanta ; 278: 126357, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38959669

RESUMEN

Methamphetamine (MA) is one of the most virulent illicit drugs that can be synthesized from household materials leading to its prevalent trafficking and local manufacturing in clandestine drug laboratories (clan labs). The significant problems of tracing MA in clan labs and monitoring drug abusers lie in the lag time between sample collection and analysis and the number of tests done. Capillary electrophoresis (CE) is a rapid separation technique amenable to miniaturization and field testing. Herein, we developed a simple transient isotachophoretic (tITP)-CE method to detect MA and its precursor pseudoephedrine (PSE) in clan labs and non-invasive biological fluids. The method was implemented on the ETD-100, a commercial fully automated portable CE instrument with an integrated swab-based extraction system. Within 2 min of insertion of the swab, MA and PSE were automatically extracted with a leading electrolyte (LE) and then separated on covalently modified capillaries. The ETD-100 showed a limit of detection (LOD) and quantification (LOQ) of MA 0.02 and 0.05 µg/swab and 0.02 and 0.06 µg/swab of PSE, with an enhancement factor of 118 and 328, respectively, when compared to a normal non-tITP injection. The intra and inter-day relative standard deviation in terms of migration time were in the range of 0.75-1.93 % for both MA and PSE and were 2.0-2.4 % for both MA and PSE peak height. The method was demonstrated with the detection of spiked MA and PSE on different household materials as well as in non-invasive biological fluids with a recovery above 60 %.

2.
Methodist Debakey Cardiovasc J ; 20(3): 49-56, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38765211

RESUMEN

For patients with existing venous thromboembolisms (VTEs), anticoagulation remains the standard of care recommended across multiple professional organizations. However, for patients who developed a deep venous thrombosis (DVT) and/or a pulmonary embolism and cannot tolerate anticoagulation, inferior vena cava (IVC) filters must be considered among other alternative treatments. Although placement of a filter is considered a low-risk intervention, there are important factors and techniques that surgeons and interventionalists should be aware of and prepared to discuss. This overview covers the basics regarding the history of filters, indications for placement, associated risks, and techniques for difficult removal.


Asunto(s)
Remoción de Dispositivos , Diseño de Prótesis , Implantación de Prótesis , Embolia Pulmonar , Filtros de Vena Cava , Trombosis de la Vena , Humanos , Embolia Pulmonar/prevención & control , Trombosis de la Vena/prevención & control , Trombosis de la Vena/terapia , Factores de Riesgo , Implantación de Prótesis/instrumentación , Implantación de Prótesis/efectos adversos , Resultado del Tratamiento , Tromboembolia Venosa/prevención & control , Tromboembolia Venosa/diagnóstico , Vena Cava Inferior/diagnóstico por imagen , Medición de Riesgo , Anticoagulantes/uso terapéutico , Anticoagulantes/efectos adversos
3.
J Vasc Surg Cases Innov Tech ; 10(1): 101374, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38130359

RESUMEN

Surgical repair of a subclavian artery mycotic aneurysm is dependent on aneurysm-specific characteristics and anatomic exposures could require sternotomy, thoracotomy, or supraclavicular incisions. Alternatively, a median claviculectomy can be used. We successfully performed a subclavian artery to axillary artery bypass with median claviculectomy in a 23-year-old man with multiple comorbidities. Postoperative Doppler ultrasound showed a patent left axillary artery with a palpable left radial artery, and the patient demonstrated full left shoulder range of motion without any significant deformities. This case suggests that a median claviculectomy can produce satisfactory outcomes in patients with subclavian artery mycotic aneurysms.

4.
Anal Chim Acta ; 1280: 341847, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37858546

RESUMEN

BACKGROUND: In capillary electrophoresis (CE), the inner surface of fused-silica capillaries is commonly covalently modified with liquid silanes to control electroosmotic flow (EOF). This liquid phase deposition (LPD) approach is challenging for long and narrow-diameter capillaries (≥1 m, ≤25 µm ID) inhibiting commercial production. Here, we use chemical vapour deposition (CVD) to covalently modify capillaries with different silanes. Using a home-built CVD device, capillaries were modified with neutral (3-glycidyloxypropyl) trimethoxysilane (GPTMS), the weak base (3-aminopropyl) trimethoxysilane (APTMS), the weak acid 3-mercaptopropyltrimethoxysilane (MPTMS) and the neutral hydrophobic trichloro(1H,1H,2H,2H-perfluorooctyl) silane (PFOCTS). Gas-phase modification of GPTMS with acid and ammonia allowed further modification of the surface prior to molecular layer deposition (MLD) of poly(p-phenylene terephthalamide) (PPTA) using the self-limiting sequential reaction between terephthalaldehyde (TA) and p-phenylenediamine (PD) vapours. RESULTS: Capillaries coated with GPTMS by CVD showed a greater reduction in EOF at all pH values than the conventional LPD. APTMS showed a reduction of the EOF at pH 9, with EOF reversal observed below pH 6. MPTMS provided a slightly lower EOF than an unmodified capillary at high pH, and a slightly higher EOF at lower pH. PFOCTS provided the most consistent EOF as a function of pH. The deposition of successive layers of PPTA resulted in increased surface coverage of the polymer and a greater reduction in EOF at pH higher than 5. The stability of a 10 µm ID GPTMS coated capillary was tested at pH 8.8 in a 200 mM CHES/Tris BGE for the separation of inorganic anions. Over 1.5 months of continuous operation (≈4130 runs), the reproducibility of the apparent mobilities for chloride, nitrite, nitrate and sulfate were 2.43%, 2.56%, 2.63% and 3.05%, respectively. The intra-day and inter-day column-to-column reproducibility and batch-to-batch reproducibility for all the coated capillaries ranged between 0.34% and 3.95%. SIGNIFICANCE: The study demonstrates the superior performance of CVD coating for suppressing the EOF compared to LPD allowing the easy modification of long lengths of narrow capillary. The variation in silane, and the ability of MLD to modify and control the surface chemistry, provides a simple and facile method for surface modification. The stability of these coatings will allow long-term capillary electrophoresis monitoring of water chemistry, such as for monitoring fertiliser run-off in natural waters.

5.
J Vasc Surg Cases Innov Tech ; 9(3): 101115, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37692905

RESUMEN

The recent decline in RAAA incidence and the fast paced scenario with associated challenges regarding training calls for initiative for a better training environment to maximize learning. This led us to the creation of a pulsatile human cadaveric RAAA model. Fresh frozen cadaver was used to create RAAA with BioTissue in hybrid suite with ability to perform CBCTA for sizing. As a proof of concept, the model was used to perform REVAR with proximal CODA balloon control. The model proved to be feasible and we believe it is a better environment to train and gain adequate proficiency in RAAA management.

6.
Curr Oncol ; 30(9): 8310-8327, 2023 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-37754518

RESUMEN

Historically, subject matter experts and healthcare professionals have played a pivotal role in driving oncology clinical trials. Although patients have been key participants, their deliberate and active contribution to the design and decision-making process has been limited. This scoping review aimed to examine the existing literature to scope the extent of active patient engagement in the design of oncology clinical trials and its corresponding influence on trial outcomes. We conducted a systematic search using two databases, namely MEDLINE (Ovid) and EMBASE, to identify relevant studies exploring patient engagement in cancer-related clinical research design. We identified seven studies that met the eligibility criteria. The studies highlighted the benefits of active patient involvement, such as improved recruitment strategies, and the attainment of more patient-centered trial outcomes. The influence of patient involvement varied from tangible developments like patient-friendly resources to indirect impacts like improved patient experiences and potentially higher adherence to trial intervention. The future of clinical trials should prioritize patients' values and perspectives, with regulatory bodies fostering these practices through clear guidelines. As the concept of patient centricity takes root in oncology research, the involvement of patients should evolve beyond mere participation.


Asunto(s)
Oncología Médica , Neoplasias , Humanos , Bases de Datos Factuales , Personal de Salud , Neoplasias/terapia , Participación del Paciente , Ensayos Clínicos como Asunto
7.
J Sep Sci ; 46(15): e2300283, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37401843

RESUMEN

Liquid chromatography is a prominent analytical technique in separation science and chemical analysis, applied across numerous fields of research and within industrial applications. Over the past few decades, there has been a growing interest in the miniaturization of this technique, which has been particularly enabled through new miniature and portable detection technologies for in-field, at-site, and point-of-need (collectively 'out-of-lab') analyses. Accordingly, significant advances have been made in recent years in the development of miniaturized liquid chromatography with photometric, electrochemical, and mass spectrometric detection, enabling the development of field-deployable and portable instruments for various applications. Herein, recent developments in the miniaturization of detection systems for inclusion within, and/or coupling with, portable liquid chromatographic systems, are reviewed in detail together with critical comments and expected future trends in this area.

8.
J Vasc Surg Venous Lymphat Disord ; 11(5): 978-985.e3, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37030443

RESUMEN

BACKGROUND: Driven by the ability to avoid thrombolytics and provide a one stop procedure with immediate hemodynamic improvement, there has been a dramatic increase in the use of mechanical thrombectomy (MT) devices for the treatment of intermediate-to-high risk pulmonary embolism (PE). This study investigated the incidence and outcomes of cardiovascular collapse during MT procedures and demonstrates the role of extracorporeal membrane oxygenation (ECMO) in salvaging patients. METHODS: This single-center retrospective review included patients with PE undergoing MT with the FlowTriever device between 2017 and 2022. Patients presenting periprocedural cardiac arrest were identified and their perioperative characteristics and postoperative outcomes were evaluated. RESULTS: A total of 151 patients with a mean age of 64 ± 14 years who presented with intermediate-to-high risk PE received LBAT procedures during the study period. The simplified PE severity score was ≥1 in 83% of cases and the average RV/LV ratio was 1.6 ± 0.5, with and elevated troponin in 84%. Technical success was achieved in 98.7% and a significant decrease in pulmonary artery systolic pressure (PASP) was observed (37 mm Hg vs 56 mm Hg; P < .0001). Intraoperative cardiac arrest occurred in nine patients (6%). These patients were more likely to present PASP of ≥70 mm Hg (84% vs 14%; P < .001), were more hypotensive upon admission (systolic of 94 ± 14 mm Hg vs 119 ± 23 mm Hg; P = .004), presented lower oxygen saturation levels (87 ± 6% vs 92 ± 6%; P = .023) and were more likely to present with a history of recent surgery (67% vs 18%; P = .004). Four patients were rescued successfully with ECMO and their residual PE was subsequently removed before discharge by surgical embolectomy in two of the four cases and repeat MT in the other two. All five patients (3%) who did not receive ECMO support expired intraoperatively. The overall 30-day mortality was 8% with no death occurring in patients who were salvaged with ECMO. CONCLUSIONS: Large-bore aspiration thrombectomy for acute PE is associated with favorable technical outcomes, but the concern for acute cardiac decompensation is non-negligible in patients presenting with high-risk features and a PASP of ≥70 mm Hg. ECMO can help to salvage some of these patients and should be considered in the treatment algorithms of patients deemed at high risk.


Asunto(s)
Oxigenación por Membrana Extracorpórea , Paro Cardíaco , Embolia Pulmonar , Humanos , Persona de Mediana Edad , Anciano , Oxigenación por Membrana Extracorpórea/métodos , Embolia Pulmonar/diagnóstico por imagen , Embolia Pulmonar/terapia , Embolia Pulmonar/complicaciones , Trombectomía/efectos adversos , Terapia Trombolítica/efectos adversos , Enfermedad Aguda , Paro Cardíaco/etiología , Paro Cardíaco/terapia , Estudios Retrospectivos
9.
Anal Chem ; 95(10): 4662-4670, 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36862378

RESUMEN

Droplet microfluidics enables high-throughput experimentation and screening by encapsulating chemical and biochemical samples in aqueous droplets segmented by an immiscible fluid. In such experiments, it is critical that each droplet remains chemically distinct. A common approach is to use fluorinated oils with surfactants to stabilize droplets. However, some small molecules have been observed to transport between droplets under these conditions. Attempts to study and mitigate this effect have relied on evaluating crosstalk using fluorescent molecules, which inherently limits the analyte scope and conclusions drawn about the mechanism of the effect. In this work, transport of low molecular weight compounds between droplets was investigated using electrospray ionization mass spectrometry (ESI-MS) for measurement. The use of ESI-MS significantly expands the scope of analytes that can be tested. We tested 36 structurally diverse analytes that were found to exhibit crosstalk ranging from negligible to complete transfer using HFE 7500 as the carrier fluid and 008-fluorosurfactant as a surfactant. Using this data set, we developed a predictive tool showing that high log P and log D values correlate with high crosstalk, and high polar surface area and log S correlate with low crosstalk. We then investigated several carrier fluids, surfactants, and flow conditions. It was discovered that transport is strongly dependent on all of these factors and that experimental design and surfactant tailoring can reduce carryover. We present evidence for mixed crosstalk mechanisms including both micellar and oil partitioning transfer. By understanding the driving mechanisms, surfactant and oil compositions can be designed to better reduce chemical transport for screening workflows.

10.
Methodist Debakey Cardiovasc J ; 19(2): 78-89, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36910549

RESUMEN

Ruptured abdominal aortic aneurysm (RAAA) is an acute aortic condition that requires emergent intervention and appropriate continuity of care to optimize patient outcomes. We describe the standardized RAAA protocol at the Houston Methodist Hospital Acute Aortic Treatment Center, developed to navigate critical patient transfer periods safely and efficiently, make crucial decisions about surgical intervention, and clearly communicate these plans with other care team providers. Our workflow is organized into five phases: prehospital, preoperative, intraoperative, postoperative, and post-discharge. We identify the transfer center, anesthesia, operating room nursing staff, surgeons, and intensive care unit as key entities of our acute aortic pathology care team. This systematic protocol for the management of acute aortic emergencies such as RAAA identifies critical decision points, potential complications at each stage, and recommendations for best practice.


Asunto(s)
Aneurisma de la Aorta Abdominal , Rotura de la Aorta , Humanos , Protestantismo , Cuidados Posteriores , Aneurisma de la Aorta Abdominal/cirugía , Alta del Paciente , Rotura de la Aorta/cirugía , Resultado del Tratamiento , Estudios Retrospectivos , Factores de Riesgo
11.
Anal Chim Acta ; 1247: 340903, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36781255

RESUMEN

Due to their size, conventional high performance liquid chromatographs (HPLCs) are difficult to place close to a reaction vessel within a pharmaceutical manufacturing or development site. Typically, long transfer lines are required to move sample from the reactor to the HPLC for analysis and high solvent usage is required. However, herein a compact and modular separation system has been developed to enable co-location of an HPLC with a small-scale reactor for reaction monitoring in the synthesis of active pharmaceutical ingredients. Using a framework based on capillary HPLC, a compact gradient separation system with a fully modular architecture is described. A custom miniature diode-array detector with a linear dynamic range (up to 1500 mAU at 210 nm) was integrated and evaluated for on-line reaction monitoring. In evaluating system suitability, average peak area %RSD of <3%, and an average retention time %RSD of <0.7%, were achieved. To demonstrate practical utility, the compact system was coupled directly to an on-line lab-scale flow through reactor for continuous reaction monitoring in the laboratory fume hood, where a study of the 3rd Bourne reaction was used to compare the performance of the compact system with a commercially available process HPLC instrument (Waters PATROL UPLC). Further, 33 off-line samples from a continuous crystallization reactor were analysed and it was found that the developed compact HPLC system showed equivalent quantitative performance to an Agilent 1290 Infinity II HPLC system.


Asunto(s)
Cromatografía Líquida de Alta Presión , Cromatografía Líquida de Alta Presión/métodos , Solventes/química , Preparaciones Farmacéuticas
12.
J Chromatogr A ; 1688: 463666, 2023 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-36528899

RESUMEN

All pharmaceutical manufacturers are required to verify that their production equipment is free from contaminants. Here, we report the capability of a fully automated portable capillary electrophoresis instrument with an integrated sample swab extraction - the Grey Scan ETD-100 - for the detection of pharmaceutical residues on surfaces of manufacturing equipment. Lidocaine was used as a model compound and could be recovered from a surface by swabbing, extracted from the swab, and analysed within 1 min. The recovery of lidocaine from a stainless-steel coupon was 81.3 %, with a LOD of 0.13 µg/swab. This fast, sensitive, and simple method implemented on a user-friendly portable CE instrument without the need for manual sample pre-treatment provides the possibility for on-site rapid determination of equipment cleanliness in the pharmaceutical industry.


Asunto(s)
Industria Farmacéutica , Acero Inoxidable , Acero Inoxidable/análisis , Electroforesis Capilar , Preparaciones Farmacéuticas
13.
Ther Adv Infect Dis ; 9: 20499361221132148, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36311554

RESUMEN

Objective: Extracorporeal membrane oxygenation (ECMO) is used to provide heart-lung bypass support in cases of acute respiratory and cardiac failure. The two main classifications of ECMO are venoarterial (VA) and venovenous (VV). After the patient recovers from an acute state, ECMO decannulation from the groin often requires femoral exploration and vessel repair. This study was performed to quantify the rate of surgical site infection (SSI) after ECMO decannulation. Methods: Retrospective single-institutional review of patients requiring ECMO from January 2016 to October 2019 was conducted. The study examined incidence of SSI. We evaluated preoperative risk factors, VA versus VV ECMO, Szilagyi infection score, and postoperative management. Results: Initial search began with 176 ECMO cases, of which 106 patients were deceased before development of any infection. Eighteen were eliminated because of central ECMO access, and four were lost to chart privacy. Of the 154 patients requiring femoral ECMO, 48 (31%) survived, with 22 VA and 26 VV ECMO. Twelve patients were classified as infected, resulting in an overall SSI rate of 25%. Surgical repair of the femoral arterial cannulation site was required in the 22 VA ECMO patients, and 10 of these became infected, resulting in an infection rate of 45%. The remaining two infected were VV ECMO and did not require surgery. The VV ECMO SSI rate was 7.7%. The infected group of VA ECMO consisted of eight primary surgical repairs and two patch repairs. Eight of the patients required multiple reoperations and two required antibiotics and wound care alone. There was no instance of limb loss. Statistical analysis showed intraoperative transfusion of >250 ml and blood loss of >300 ml as the only predictive factors of infection. The Szilagyi score was found to be worse in patients requiring patch angioplasty. Conclusion: Surgical repair of ECMO arterial cannulation sites had postoperative SSIs in nearly half of the patients (45%). The VV ECMO SSI rate was found to be 7.7%. Severity of infection was worse in more complicated repairs. Overall ECMO mortality was high at 69%. Although we found no clear correlation with common risk factors, transfusions >250 ml and blood loss >300 ml were found to be predictive. Vascular surgeons should be aware of high risk of SSI with repair of femoral ECMO cannulation sites.

14.
IEEE J Transl Eng Health Med ; 10: 1900309, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35992372

RESUMEN

Objective: To evaluate a novel technology for real time tracking of RF-Identified (RFID) surgical tools (Biotic System), providing intraoperative data analytics during simulated cardiovascular procedures. Ineffective asset management in the Operating Room (OR) leads to inefficient utilization of resources and contributes to prolonged operative times and increased costs. Analysis of captured data can assist in quantifying instrument utilization, procedure flow, performance and prevention of retained instruments. Methods & Results: Five surgeons performed thirteen simulated surgical cases on three human cadavers. Procedures included (i) two abdominal aortic aneurysm (AAA) repairs, (ii) three carotid endarterectomies (CE), (iii) two femoropopliteal (fem-pop) bypasses, (iv) thoracic aortic aneurysm repair, (v) coronary artery bypass graft, (vi) aortic valve replacement, (vii) ascending aortic aneurysm repair, (viii) heart transplants, and (ix) mitral valve replacement. For each case an average of 139 surgical instruments were RFID-tagged and tracked intraoperatively. Data was captured and analyzed retrospectively. Of the 139 instruments tracked across each of the 13 cases, 55 instruments (39.5%) were actually used, demonstrating a high level of redundancy. For repeat cases (i.e. CE/AAA/fem-pop): (i) average instrument usage was 41 ± 3.6 (8.8% variation) for CE (n=3); (ii) average instrument usage was 69 ± 4.0 (5.8% variation) for AAA (n=2); and (iii) average instrument usage was 48 ± 2.5 (5.3% variation) for fem- pop (n=2). Results also showed a reduction in end-of-procedure instrument counting times of 58-87%. Conclusions: We report on a method for collecting intraoperative data analytics regarding instrument usage via RFID technology. This system will help refine instrument selection, quantitate instrument utilization and prevent inadvertent retention in a patient. This should help increase efficiency in packaging and sterilization and let surgeons make objective decisions in the composition of surgical trays. Clinical and Translational Impact Statement-Intraoperative analytics of surgical tools and associated equipment may ultimately lead to safer more efficient surgeries that increase patient outcomes while decreasing the cost of care.


Asunto(s)
Aneurisma de la Aorta Abdominal , Dispositivo de Identificación por Radiofrecuencia , Aneurisma de la Aorta Abdominal/cirugía , Humanos , Quirófanos , Dispositivo de Identificación por Radiofrecuencia/métodos , Estudios Retrospectivos , Instrumentos Quirúrgicos
15.
J Chromatogr A ; 1661: 462612, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34844738

RESUMEN

Pesticides are used extensively in a wide range of applications and due to their high rate of consumption, they are ubiquitous in the different media and samples like environment, water sources, air, soil, biological materials, wastes (liquids, solids or sludges), vegetables and fruits, where they can persist for long periods. Pesticides often have hazardous side effects and can cause a range of harmful diseases like Parkinson, Alzheimer, asthma, depression and anxiety, cancer, etc, even at low concentrations. To this end, extraction, pre-concentration and determination of pesticides from various samples presents significant challenges caused by sample complexity and the low concentrations of them in many samples. Often, direct extraction and determination of pesticides are impossible due to their low concentrations and the complexity of samples. The main goals of sample preparation are removing interfering species, pre-concentrating target analyte/s and converting the analytes into more stable forms (when needed). The most popular approach is solid-phase extraction due to its simplicity, efficiency, ease of operation and low cost. This method is based on using a wide variety of materials, among which covalent organic frameworks (COFs) can be identified as an emerging class of highly versatile materials exhibiting advantageous properties, such as a porous and crystalline structure, pre-designable structure, high physical and chemical stability, ease of modification, high surface area and high adsorption capacity. The present review will cover recent developments in synthesis and applications of COFs and their composites for extraction of pesticides, different synthesis approaches of COFs, possible mechanisms for interaction of COFs-based adsorbents with pesticides and finally, future prospects and challenges in the fabrication and utilization of COFs and their composites for extraction of pesticides.


Asunto(s)
Estructuras Metalorgánicas , Plaguicidas , Adsorción , Plaguicidas/análisis , Extracción en Fase Sólida , Verduras
16.
J Vasc Surg Cases Innov Tech ; 7(4): 781-784, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34825120

RESUMEN

Central venous obstruction in the symptomatic patient is often treated with endovascular stenting. A rare, but serious, complication of this treatment is migration of the stent from the original site of deployment. Treatment of this complication requires either open or endovascular retrieval of the displaced stent. To treat a rare, but potentially devastating, complication, we have presented an effective endovascular method for migrated stent retrieval using a combination of a large bore sheath, balloon, and snare.

17.
J Chromatogr A ; 1656: 462545, 2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34543882

RESUMEN

Liquid chromatography (LC) has broad applicability in the pharmaceutical industry, from the early stages of drug discovery to reaction monitoring and process control. However, small footprint, truly portable LC systems have not yet been demonstrated and fully evaluated practically for on-line, in-line or at-line pharmaceutical analysis. Herein, a portable, briefcase-sized capillary LC fitted with a miniature multi-deep UV-LED detector has been developed and interfaced with a portable mass spectrometer for on-site pharmaceutical analysis. With this configuration, the combined small footprint portable LC-UV/MS system was utilized for the determination of small molecule pharmaceuticals and reaction monitoring. The LC-UV/MS system was interfaced directly with a process sample cart and applied to automated pharmaceutical analysis, as well as also being benchmarked against a commercial process UPLC system (Waters PATROL system). The portable system gave low detection limits (∼3 ppb), a wide dynamic range (up to 200 ppm) and was used to confirm the identity of reaction impurities and for studying the kinetics of synthesis. The developed platform showed robust performance for automated process analysis, with less than 5.0% relative standard deviation (RSD) on sample-to-sample reproducibility, and less than 2% carryover between samples. The system has been shown to significantly increase throughput by providing near real-time analysis and to improve understanding of synthetic processes.


Asunto(s)
Preparaciones Farmacéuticas , Cromatografía Liquida , Espectrometría de Masas , Reproducibilidad de los Resultados
18.
Anal Chem ; 93(35): 12032-12040, 2021 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-34436859

RESUMEN

Per- and polyfluoroalkyl substances (PFASs) are emerging environmental pollutants of global concern. For rapid field site evaluation, there are very few sensitive, field-deployable analytical techniques. In this work, a portable lightweight capillary liquid chromatography (capLC) system was coupled with a small footprint portable mass spectrometer and configured for field-based applications. Further, an at-site ultrasound-assisted extraction (pUAE) methodology was developed and applied with a portable capLC/mass spectrometry (MS) system for on-site analysis of PFASs in real soil samples. The influential variables on the integration of capLC with MS and on the resolution and signal intensity of the capLC/MS setup were investigated. The important parameters affecting the efficiency of the pUAE method were also studied and optimized using the response surface methodology based on a central composite design. The mean recovery for 11 PFASs ranged between 70 and 110%, with relative standard deviations ranging from 3 to 12%. In-field method sensitivity for 12 PFASs ranged from 0.6 to 0.1 ng/g, with wide dynamic ranges (1-600 ng/g) and excellent linearities (R2 > 0.991). The in-field portable system was benchmarked against a commercial lab-based LC-tandem MS (MS/MS) system for the analysis of PFASs in real soil samples, with the results showing good agreement. When deployed to a field site, 12 PFASs were detected and identified in real soil samples at concentrations ranging from 8.1 ng/g (for perfluorooctanesulfonic acid) to 2935.0 ng/g (perfluorohexanesulfonic acid).


Asunto(s)
Contaminantes Ambientales , Fluorocarburos , Contaminantes Químicos del Agua , Cromatografía Liquida , Fluorocarburos/análisis , Suelo , Espectrometría de Masas en Tándem , Contaminantes Químicos del Agua/análisis
19.
Talanta ; 233: 122583, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34215075

RESUMEN

Carbon nanospheres (CNSs) were derived hydrothermally from biomass (orange peels) and decorated by manganese dioxide (MnO2) nanosheets. The MnO2/CNSs nanocomposite was intercalated into polypyrrole (PPy) during flow-through in-situ electropolymerization of pyrrole on the surface of the inner wall of a stainless-steel needle to prepare an inside-needle capillary adsorption trap (INCAT) device. The surface morphology, thermogravimetric behavior, sorption characteristics, and structure of the MnO2/CNSs@PPy nanocomposite were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), nitrogen physisorption by the Brunauer-Emmett-Teller (BET) method, dynamic light scattering (DLS) size distribution, and Fourier-transform infrared spectrometry (FT-IR). The INCAT device was coupled with GC-FID and applied for dynamic headspace analysis of linear alkyl benzenes (LABs) in wastewater samples. The effective experimental variables on the extraction efficiency was optimized using a central composite design (CCD) based on response surface methodology (RSM). Under the optimal conditions, the limits of detection (LODs) were in the range of 0.5-1.0 ng mL-1. The calibration plots were linear over the range of 0.01-10 µg mL-1. The relative standard deviations (RSDs%) for intra-day, inter-day, and inter-INCAT precision were calculated 5.3-8.3%, 9.4-13.5%, and 13.6-16.9%, respectively. The developed technique was employed successfully for the analysis of LABs in water and wastewater samples with average recovery values ranging from 92 to 109%. A single INCAT device was used more than 90 times without significant change in its extraction capability.


Asunto(s)
Nanosferas , Polímeros , Adsorción , Biomasa , Carbono , Cromatografía de Gases y Espectrometría de Masas , Compuestos de Manganeso , Óxidos , Pirroles , Espectroscopía Infrarroja por Transformada de Fourier
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...