| 1. |
- Abdel-Rehim, Abbi, et al.
(författare)
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Advantages of Saliva Sampling in Bioanalysis Using Microextraction by Packed Sorbent and Dried Saliva Spot with LC-MS-MS
- 2014
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Ingår i: LC GC Europe. - 1471-6577. ; 27:10, s. 529-531
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Tidskriftsartikel (refereegranskat)abstract
- Saliva offers a fast and non-invasive sampling matrix for determining drug concentration levels, making it a suitable alternative to plasma and blood. During the analysis of biological samples attention is focused on sample pre-treatment. In addition, liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) is often the method of choice in bioanalysis because of the good selectivity and good sensitivity of the technique. In this article, two sample handling and sample preparation methods for saliva samples are presented and discussed. The first method is microextraction by packed sorbent (MEPS), and the second method is dried saliva spot (DSS). Both methods were applied for determining the presence of lidocaine in saliva.
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| 2. |
- Abdel-Rehim, Abbi, et al.
(författare)
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Dried saliva spot as a sampling technique for saliva samples
- 2014
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Ingår i: BMC Biomedical chromotography. - : Wiley. - 0269-3879 .- 1099-0801. ; 28:6, s. 875-877
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, dried saliva spot (DSS) was used as a sampling technique for saliva samples. In the DSS technique 50 L of saliva was collected on filter paper and the saliva was then extracted with an organic solvent. The local anesthetic lidocaine was used as a model compound, which was determined in the DSS using liquid chromatography and mass spectrometry. The results obtained for the determination of lidocaine in saliva using DSS were compared with those from a previous study using a microextraction by packed sorbent syringe as the sampling method for saliva. This study shows that DSS can be used for the analysis of saliva samples. The method is promising and very easy in terms of sampling and extraction procedures. The results from this study are in good agreement with those from our previous work on the determination of lidocaine in saliva. DSS can open a new dimension in the saliva handling process in terms of sampling, storing and transport.
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| 3. |
- Abdel-Rehim, Abbi, et al.
(författare)
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Evaluation of microextraction by packed sorbent and micro-liquid chromatography-tandem mass spectrometry as a green approach in bioanalysis
- 2013
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Ingår i: BMC Biomedical chromotography. - : Wiley. - 0269-3879 .- 1099-0801. ; 27:10, s. 1225-1233
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Tidskriftsartikel (refereegranskat)abstract
- In this study the use of micro-liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was investigated in routine bioanalysis application for separation and quantification of pro-drug AZD6319 (developed for aldezheimer treatment). Microextraction by packed sorbent (MEPS) was used as sample clean-up method. The focus of this study was put on the evaluation of the usability of smaller column diameters such as 1.0 and 0.3mm instead of 2.1mm in bioanalysis application to reduce solvent consumption and sample volumes. Solvent consumption was reduced by 80% when a 1.0mm column was used compared with 2.1mm column. Robustness of the micro-columns in terms of accuracy and precision was investigated. The application of LC-MS/MS for the quantitative analysis of AZD6319 in plasma samples showed good selectivity, accuracy and precision. The coefficients of determination (R-2) were >0.998 for all runs using plasma samples on the studied micro-columns. The inter-day accuracy values for quality control samples ranged from 99 to 103% and from 96 to 105% for 0.3x50mm and 1.0x50mm columns, respectively. The inter-day precision values ranged from 4.0 to 9.0% and from 4.0 to 8.0% for 0.3x50 and 1.0x50mm columns, respectively. In addition the sensitivity was increased by three times using a 1.0mm column compared with 2.1mm. Furthermore, robustness of the micro-columns from different manufacturers was investigated.
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| 4. |
- Abdel Rehim, Abbi, et al.
(författare)
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Screening and determination of drugs in human saliva utilizing microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry
- 2013
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Ingår i: BMC Biomedical chromotography. - : Wiley. - 0269-3879 .- 1099-0801. ; 27:9, s. 1188-1191
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Tidskriftsartikel (refereegranskat)abstract
- This study presents a new method for collecting and handling saliva samples using an automated analytical microsyringe and microextraction by packed syringe (MEPS). The screening and determination of lidocaine in human saliva samples utilizing MEPS and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were carried out. An exact volume of saliva could be collected. The MEPS C-8-cartridge could be used for 50 extractions before it was discarded. The extraction recovery was about 60%. The pharmacokinetic curve of lidocaine in saliva using MEPS-LC-MS/MS is reported.
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| 5. |
- Abdel-Rehim, Mohamed, et al.
(författare)
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Microextraction approaches for bioanalytical applications : An overview
- 2020
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Ingår i: Journal of Chromatography A. - : Elsevier B.V.. - 0021-9673 .- 1873-3778. ; 1616
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Tidskriftsartikel (refereegranskat)abstract
- Biological samples are usually complex matrices due to the presence of proteins, salts and a variety of organic compounds with chemical properties similar to those of the target analytes. Therefore, sample preparation is often mandatory in order to isolate the analytes from troublesome matrices before instrumental analysis. Because the number of samples in drug development, doping analysis, forensic science, toxicological analysis, and preclinical and clinical assays is steadily increasing, novel high throughput sample preparation approaches are calling for. The key factors in this development are the miniaturization and the automation of the sample preparation approaches so as to cope with most of the twelve principles of green chemistry. In this review, recent trends in sample preparation and novel strategies will be discussed in detail with particular focus on sorptive and liquid-phase microextraction in bioanalysis. The actual applicability of selective sorbents is also considered. Additionally, the role of 3D printing in microextraction for bioanalytical methods will be pinpointed.
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| 6. |
- Aboul-Enein, Mohamed N., et al.
(författare)
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Design and synthesis of novel stiripentol analogues as potential anticonvulsants
- 2012
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 47, s. 360-369
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Tidskriftsartikel (refereegranskat)abstract
- A series of stiripentol (SIP) analogues namely, 2-1(1E)-1-(1,3-benzodioxol-5-yl)-4,4-dimethylpent-1-en-3-ylidene]-N-(aryl/H)hydrazinecarboxamides 7a-h, (+/-)-(5RS)-N-(aryl/H)-(1,3-benzodioxol-5-yl)-3-tert-butyl-4,5-dihydro-1H-pyrazole-1-carboxamides (+/-)-8a-h, and (+/-)-[(5RS)-(1,3-benzodioxol-5-yl)-3-tert-butyl-4,5-dihydro-1H-pyrazol-1-yl](aryl)methanones (+/-)-13a-f was synthesized by adopting appropriate synthetic routes and was pharmacologically evaluated in the preliminary anticonvulsant screens. The selected bioactive new chemical entities were subjected to ED50 determination and neurotoxicity evaluation. The most active congeners are 7h in MES screen and (+/-)-13b in scPTZ screen which displayed ED50 values of 87 and 110 mg/kg, respectively, as compared to that of STP (ED50 = 277.7 and 115 mg/kg in MES and scPTZ, respectively). (C) 2011 Elsevier Masson SAS. All rights reserved.
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| 7. |
- Daryanavard, S. M., et al.
(författare)
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Recent applications of microextraction sample preparation techniques in biological samples analysis
- 2021
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Ingår i: BMC Biomedical chromotography. - : Wiley. - 0269-3879 .- 1099-0801. ; 35:7
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of biological samples is affected by interfering substances with chemical properties similar to those of the target analytes, such as drugs. Biological samples such as whole blood, plasma, serum, urine and saliva must be properly processed for separation, purification, enrichment and chemical modification to meet the requirements of the analytical instruments. This causes the sample preparation stage to be of undeniable importance in the analysis of such samples through methods such as microextraction techniques. The scope of this review will cover a comprehensive summary of available literature data on microextraction techniques playing a key role for analytical purposes, methods of their implementation in common biological samples, and finally, the most recent examples of application of microextraction techniques in preconcentration of analytes from urine, blood and saliva samples. The objectives and merits of each microextration technique are carefully described in detail with respect to the nature of the biological samples. This review presents the most recent and innovative work published on microextraction application in common biological samples, mostly focused on original studies reported from 2017 to date. The main sections of this review comprise an introduction to the microextraction techniques supported by recent application studies involving quantitative and qualitative results and summaries of the most significant, recently published applications of microextracion methods in biological samples. This article considers recent applications of several microextraction techniques in the field of sample preparation for biological samples including urine, blood and saliva, with consideration for extraction techniques, sample preparation and instrumental detection systems.
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| 8. |
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| 9. |
- Moein, Mohammad Mahdi, et al.
(författare)
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Microextraction by packed sorbent (MEPS)
- 2015
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier BV. - 0165-9936 .- 1879-3142. ; 67, s. 34-44
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Forskningsöversikt (refereegranskat)abstract
- Sample preparation is an important stage in separation and determination of components of interest from complex matrices. Sample preparation strongly influences the reliability and the accuracy of the analysis and the data quality. Recent trends in sample preparation include miniaturization, automation, high-throughput performance, on-line coupling with analytical instruments and low-cost operation using little or no solvent consumption. In the past decade, microextraction by packed sorbent (MEPS) was introduced as a simple, fast, on-line sample-preparation technique. Also, MEPS requires less sample and less solvent. This review gives an outline of the MEPS technique, including fields of application, common formats and sorbents, factors that affect performance, and the major advantages and limitations. Further, we offer and discuss our perspective on the future of MEPS.
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| 10. |
- Moein, M. M., et al.
(författare)
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Nanomaterials for microextraction techniques in bioanalysis
- 2019
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Ingår i: Handbook of Nanomaterials in Analytical Chemistry. - : Elsevier BV. ; , s. 43-56
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The analysis of biological samples (bioanalysis) always needs intensive sample cleanup (sample preparation) before it gets injected into the analytical instruments. In bioanalysis, sample preparation has an essential role because of the complexity of the biological matrix. Among popular sample preparation techniques, microextraction techniques received high attention because of needs of low volume of used solvent and sample. The sorbent may has high influence on the method selectivity and recovery. Because of their high surface area, ultra-small size, high physical and chemical stability properties, nanomaterials attained huge attention in sample preparation for analytical and bioanalytical trends. In this chapter, the different types and applications of nanomaterials in microextraction analysis and bioanalysis will be summarized and discussed. In addition, recently published papers on the relevance of nanomaterials as sorbents in microextraction for bioanalysis will be presented and the application of nanomaterials for online analysis procedures will be included.
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