Analytical Chemistry Journals Research Articles

BrJAC 2023 – Growing and Building Bridges

BrJAC 2023 – Growing and Building Bridges

Analytical Chemistry is like the Fruit of an Apple Tree

Analytical chemistry is deeply rooted in Europe. It started with the work of Liebig and Fresenius, among others. Then Kirchhoff, as father of spectroscopy, contributed to the development of the modern instrumental analysis techniques flourishing today. As soon as I started learning analytical chemistry at university, I fell in love with it. At that time, I could not explain why I wanted to become an analytical chemist. Having gained experience teaching and performing research in analytical chemistry, I know now that I am attracted to it because this branch of chemistry is what an apple means to an apple tree - the fruit of a myriad of results in fundamental research in chemistry, always offering solutions to real life problems. I always wanted to become an analyst and to work at the analytical chemistry department where I studied. One year ago, my life drastically changed at the institute when I was invited to apply to lead the analytical chemistry department where I have been working since 2007. I must admit that I had mixed feelings in the beginning. First of all, I was honored that my colleagues in the department fully expressed their support. At the same time, I was confused and scared. I felt that I am not the right person to lead a department with a history of almost 120 years, that I had no clear vision of what could I do for my colleagues and for the students choosing our department. However, I wanted to express my gratitude to my colleagues for their trust in me. In my application, I advocated to maintain the high-quality teaching of analytical chemistry at the department and offered to implement challenge-based learning for students choosing our department. In past years, I felt that the raison d'être of analytical chemistry departments as single entities would soon end. My colleagues working in other fields such as biology, geography and geology, pharmacy and medicine, all purchased instrumental analytical equipment and started performing research by themselves. Recently, analytical chemistry departments underwent important organizational and structural changes. Some of them disappeared, others incorporated into their name environmental chemistry, food chemistry, or biochemistry. Recent advances in instrumental analysis create the impression that conducting chemical analysis is an easy task that no longer requires the expertise of chemists devoted to this branch of chemistry. However, there is still a lot of work to do, especially in the field of organic analytical chemistry. Thanks to innovations in mass spectrometry and related techniques, infrared spectroscopy, miniaturization (lab-on-chips) and sensors, ultra trace analysis, green methodologies, and elemental speciation, analytical chemistry is experiencing a second Golden Era. In last year alone, I was surprised by the ever-increasing number of chemistry bachelor and major students knocking on my door asking me to provide them with analytical chemistry-related research topics. That led me to contact faculty working at the other institutes offering cooperation with the arsenal of our instruments to widen the research topic choices in our department, advocating that we should unite and complement our efforts to create synergies. Surprisingly, the response of those colleagues was very positive. In one year, I could almost double the number of research topics for diploma work in our department. This is something that makes me happy and optimistic. I am confident that the development of analytical methods together with proper sampling and sample preparation are still important and crucial steps to produce high quality and reliable results. Moreover, participation of analytical chemists in these tasks is indispensable. The recent success of the Brazilian Journal of Analytical Chemistry achieving an impact factor of 0.7 makes me also think that analytical method development has still a bright future ahead. Long live Analytical Chemistry! Long live Brazilian Journal of Analytical Chemistry!

Patricia Smichowski, a researcher who works hard to contribute to science, kindly granted BrJAC an interview

Patricia Smichowski is a Licentiate in Chemistry (equivalent to a Master in Science) of the University of Buenos Aires. She obtained an MS in Nuclear Engineering from the Engineering School of the University of Buenos Aires in 1981 and received her Ph.D. in chemistry in 1995 from the Complutense University, Madrid, Spain. In 1982, she joined the Argentine Atomic Energy Commission (CNEA) where she is currently Head of the Analytical Developments Division. She is also Principal Researcher at the National Council of Scientific and Technical Research (CONICET). She specializes in the development and application of atomic spectrometric techniques to environmental and biological analysis. Her interests lie in the preconcentration, speciation, and determination of trace metals and metalloids in a variety of matrices by employing plasma-based techniques, atomic fluorescence spectrometry, and other coupled techniques. She has conducted national and international projects aimed at characterizing the presence of metals, metalloids, ions, and organic compounds in airborne particulate matter, as well as elucidating their origin. She holds a patent, with other researchers, relating to the development of a sorbent for arsenic retention. Patricia Smichowski has published 130 peer reviewed articles and 12 book chapters, given 45 invited lectures at international meetings, and has co-organized several international conferences. She is a member of the advisory board of four international analytical chemistry journals, as well as the European Virtual Institute for Speciation Analysis.

Corrigendum to Determination of fluorine and chlorine in standard steel residues and zinc sulfide concentrates by ion chromatography-matrix interference study: [Chinese Journal of Analytical Chemistry 51 (2023) 1–8/100147

Corrigendum to Determination of fluorine and chlorine in standard steel residues and zinc sulfide concentrates by ion chromatography-matrix interference study: [Chinese Journal of Analytical Chemistry 51 (2023) 1–8/100147

Pavlinsky Geliy Veniaminovich (1935–2023)

Pavlinsky Geliy Veniaminovich (1935–2023)

(Digital Presentation) Electrochemical Glutamate Sensor Using Copper Oxide Nanomaterials Functionalized with Multiwall Carbon Nanotubes

Glutamate is the most abundant neurotransmitter in the central nervous system (CNS) and plays an important role in different physiological processes. Excess amounts of glutamate cause excitotoxicity resulting in different diseases such as Alzheimer’s and glioma, pain disorders, spinal cord injuries, and cancer1-4. The concentration of glutamate in body fluids such as saliva is associated with those diseases. Therefore, glutamate is a potential biomarker for pathologies. By measuring glutamate levels in biofluids these pathologies can be monitored.Lab-based techniques such as liquid chromatography and gas chromatography offer a low limit of detection, high sensitivity, and precise detection of biomarkers4-7. These techniques are expensive, bulky, time-consuming, and require skilled personnel to operate them and therefore are not suitable for wearable and personalized healthcare applications. In contrast, electrochemical sensors are simple, low-cost, handy, and offer rapid and high sensing performance of biomarkers/analytes8,9.In this work, we fabricated a very simple, low-cost, and reusable enzyme-free electrochemical sensor using copper oxide (CuO) nanomaterials for label-free detection of glutamate. CuO nanomaterials were synthesized by a low-cost wet chemical process. The CuO nanomaterials were dispersed in DI water and the working electrode was prepared by drop casting of CuO dispersion on a screen-printed carbon electrode (SPCE). Multiwall carbon nanotubes (MWCNTs) were used with CuO to enhance the electron transfer from CuO to SPCE (Figure a). Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to perform glutamate sensing in deionized (DI) water at pH 7.4. The peak oxidation current (I pa) is proportional to glutamate (G) presence in DI water (Figure b). The sensor showed good oxidation current event at a low concentration of glutamate (20 µM) in DI water. The normal concentrations of glutamate in body fluids such as plasma and saliva are about 5-100 µM, and 1-30 µM respectively 3. Therefore, CuO nanostructure-based nonenzymatic electrochemical sensor is very potential for low cost, portable, rapid detection of glutamate in those body fluids. We will further discuss details of CuO synthesis, electrode fabrication process, sensing mechanism, and challenges of the glutamate sensor.References Lewerenz and P. Maher, Frontiers in neuroscience. 9 (2015) 469.Takano et al., Nature medicine. 7 (2001) 1010-1015.H Jasim et al., Scientific reports 8.1 (2018): 1-9.Schultz, Z. Uddin, G. Singh, and M. M. Howlader, Analyst. 145 (2020) 321-347.Klimuntowski, M. M. Alam, G. Singh, and M. M. Howlader, ACS Sensor. 5(3) (2020) 620–636.Budczies et al., International journal of cancer. 136 (2015) 1619-1628.Xin et al, Chinese Journal of Analytical Chemistry. 35 (2007), 1151-1154.Hughes et al., Sensors and Actuators B: Chemical. 216 (2015) 614-621.Rocchitta et al., Sensors, 16 (2016) 780.X Zhang et al., The Journal of Physical Chemistry C 112.43 (2008): 16845-16849.Y Li et al., Materials Research Bulletin 43.8-9 (2008): 2380-2385.RP Allaker, and Z Yuan, Nanobiomaterials in clinical dentistry. Elsevier, 2019. 243-275. Figure 1

Annual review of capillary electrophoresis technology in 2021

该文为2021年毛细管电泳(capillary electrophoresis, CE)技术年度回顾。归纳总结了以“capillary electrophoresis-mass spectrometry”或“capillary isoelectric focusing”或“micellar electrokinetic chromatography”或“capillary electrophoresis”为关键词在ISI Web of Science数据库中进行主题检索(排除“capillary electrochromatography”“microchip”和“capillary monolithic column”)得到的2021年CE技术相关研究论文291篇,以及中文期刊《色谱》和《分析化学》中相关研究论文9篇。重点介绍了影响因子(IF)≥10.0的Coordination Chemistry Reviews, Angewandte Chemie-International Edition, Nature Protocols, TrAC-Trends in Analytical Chemistry, Signal Transduction and Targeted Therapy发表的7篇论文;以及影响因子5~10之间的代表性期刊Analytical Chemistry, Analytica Chimica Acta, Talanta和Food Chemistry的42篇论文;对影响因子小于5但CE技术报道较为集中的Journal of Chromatography A和Electrophoresis,国内重要的中文期刊《色谱》和《分析化学》中的代表性工作进行了概述。该文根据国际通用学术水平评价指标之一的影响因子选择期刊,结合期刊发表CE论文代表性工作进行介绍,便于读者快速了解毛细管电泳技术在过去一年的重要研究进展。

What if using certified reference materials (CRMs) was a requirement to publish in analytical/bioanalytical chemistry journals?

Certified reference materials (CRMs) are routinely used by analytical chemists to validate new analytical methods and to demonstrate the quality of their quantitative measurements. Even though CRMs for trace element and trace organic analysis have been available and widely used for over 50years, the majority of papers published in analytical chemistry journals do not mention the use of CRMs. What if analytical/bioanalytical chemistry journals required the use of CRMs to publish a paper? This feature article attempts to address this question by providing examples of recent papers that have made exceptional use of CRMs to validate new analytical methods and to describe novel, alternative uses of CRMs that provide new characterization of the CRM. The potential benefits of using a CRM even when it does not have certified values for the analytes of interest are presented.

BrJAC mourns the death of Prof. Dr. Miguel Valcárcel Cases and recognizes his great contribution to Analytical Chemistry and Science around the World

Who has not seen or heard about books such as Analytical Chemistry: A Modern Approach to Analytical Science, Principles of Analytical Chemistry: A Textbook, or Foundations of Analytical Chemistry: A Teaching-Learning Approach, or about flow injection analysis-FIA, and sequential injection analysis-SIA? These are, in fact, some contributions from Prof. Miguel Valcárcel Cases, at the University of Córdoba-Spain, who leave us on 9th January 2022 at the age of 75. Prof. Valcárcel was Dean of the Faculty of Sciences at the University of Córdoba, Vice-Rector for academic guidance and teaching and Vice-Rector for quality, as well as the first Director of the Andalusian Institute of Fine Chemistry and Nanochemistry since 1994. Born in Barcelona (Spain), Prof. Valcárcel was a graduate of the University of Seville where also obtained his Ph.D., and was an assistant teacher until 1975. He was an associate professor of Analytical Chemistry at the Faculty of Science of Palma de Mallorca in 1975, an institution where he was also Dean and full professor at the University of Cordoba in the year 1976. He was also President of the Analytical Division of the European Federation of Chemical Societies and was a member for 4 years of the High-Level Expert Group of the European Union's Growth Program. Valcárcel received the Spanish national Enrique Moles prize for Chemical Science and Technology (2005), the Maimónides prize for scientific-technical research from the Junta de Andalucia (1992), and the Solvay Research Prize in Chemical Sciences from the CEOE Foundation (1997). He has the Robert Boyle Medal from the Royal Society of Chemistry (UK, 2004), the Enrich Planquette Prize from the Austrian Chemical Society (1996), the Gold Medal from the University of Warsaw (2000), and the Medal from the Portuguese Chemical Society (2000). He also received the distinction of Cordoba citizen of the year 2006 in the education/research section, and the Averroes de Oro-Cuidad de Córdoba medal in 2006 for his scientific trajectory. He was also awarded the title of Doctor Honoris Causa by the University of Valencia (2010) and the European DAC-EuChMS (Division of Analytical Chemistry of the European Association for Chemical and Molecular Sciences) award in recognition of his scientific and teaching career (2015). He was the author of ca. 700 papers, published 9 scientific books, and co-authored 15 chapters of multi-author books. Owner of a unique vitality and a very accurate vision of Analytical Chemistry, Prof. Valcárcel contributed to the formation of dozens of students, of which he was extremely proud, and some of them are today Full professors spread all over the world. The Brazilian Journal of Analytical Chemistry mourns his death, and through this simple tribute, recognizes his great contribution to Analytical Chemistry and science around the world.

Spectrophotometric Determination of Fe(II) and Fe(III) Using 5-(4-Ethylphenyl azo ) 2-Hydroxybenzaldehyde Oxime Reagent

Spectrophotometric Determination of Fe(II) and Fe(III) Using 5-(4-Ethylphenyl azo ) 2-Hydroxybenzaldehyde Oxime Reagent

Prof. Santelli, a Tireless Researcher and a Gold-Standard Professor in Analytical Chemistry, kindly spoke to BrJAC

Prof. Dr. Ricardo Erthal Santelli has a degree in Pharmacy from the Federal Fluminense University, Niterói, RJ, BR (1972), a master's degree in Inorganic Analytical Chemistry from the Pontifical Catholic University, Rio de Janeiro, RJ, BR (1978), a doctorate in Inorganic Analytical Chemistry from the same institution (1985), and a postdoctoral degree from the University of Córdoba, Spain (1988). He was a full professor of Environmental Geochemistry at the Federal Fluminense University from 1994 until 2010 when he retired. He is currently Full Professor at the Institute of Chemistry at the Federal University of Rio de Janeiro, BR. He works mainly with the development of spectrometric and chromatographic methods, continuous flow injection analysis, and speciation analysis. He develops research mainly on automation in analytical chemistry, environmental geochemistry, and analytical techniques applied to environmental problems. Prof. Santelli has more than 140 scientific articles published in international journals, with more than 5800 citations and an H-index of 32 in addition to several chapters in international books. He has supervised more than 30 master’s and 15 doctoral students. In the editorial field, Prof. Santelli is currently a member of the Editorial Board of the Brazilian Journal of Analytical Chemistry.

Interlaboratory consensus building

Determining the degree of equivalence of participating laboratories from the results of measurement comparisons still prompts discussions among metrologists, especially where measurement uncertainties have been underestimated. This paper expands on a solution to a problem issued in 2020 by the Journal of Analytical and Bioanalytical Chemistry. The example illustrates an approach to consensus-building based on Bayesian selection among statistical models that attempt to explain the excess of data variation. The probability of any further model being correct can be similarly calculated.

Annual review of capillary electrophoresis technology in 2020

该文为2020年毛细管电泳(capillary electrophoresis, CE)技术年度回顾。归纳总结了以“capillary electrophoresis-mass spectrometry”或“capillary isoelectric focusing”或“micellar electrokinetic chromatography”或“capillary electrophoresis”为关键词在ISI Web of Science数据库中进行主题检索得到的2020年CE技术相关研究论文222篇,以及中文期刊《分析化学》和《色谱》中CE技术相关的研究论文37篇。对2020年影响因子(IF)≥5.0的Analytical Chemistry, Food Chemistry, Analytica Chimica Acta和Talanta等13本期刊的38篇文章报道的科研工作作了逐一介绍;对IF<5.0的期刊中CE技术报道较为集中的Journal of Chromatography A和Electrophoresis两本分析化学类期刊发表40篇文章中的代表性内容作了综合介绍;对重要的中文期刊《分析化学》出版的“核酸适配体专刊”和《色谱》出版的2期CE技术专刊所收录的37篇文章中的工作作了总体介绍。总体来说,2020年CE技术发展趋势仍以毛细管电泳-质谱(CE-MS)的新方法和新应用最为突出,主要集中在CE-MS与电化学检测、固相萃取以及多种毛细管电泳模式的联用方面,CE-MS接口相关的报道较前几年有所减少;常规CE技术则以胶束电动毛细管色谱(MEKC)在复杂样本分析、浓缩富集应用为主,尤其在食品和药品等复杂基质样本分析方面的报道较为集中;此外,我国CE相关领域专家学者的科研成果涵盖了CE在生命科学、临床医学、医药研发、环境科学、天然产物、食品分析等领域的应用,代表了国内CE科研应用水平和现状。

An Investigation of the Ammonia-Sensing Mechanism of α-MoO3-Based Chemi-Resistive Sensors

Chemi-resistive ammonia sensors based on alpha-phase molybdenum trioxide (α-MoO3) are a simple and selective technology for measuring the concentration of gaseous ammonia for applications such as human breath sensing and monitoring selective catalytic reduction (SCR) systems [1-7]. The basic operating principle of these sensors is the correlation between the electrical resistance of the sensor and the concentration of ammonia to which the sensor is exposed. Typically, the sensor consists of an interdigitated electrode substrate covered with the α-MoO3 film [1-7]. The electrical resistance of the α-MoO3 film changes as a function of ammonia concentration. This change in resistance of the α-MoO3 film is commonly attributed to the alteration of the charge depletion layer (Λ) of the α-MoO3 particles through the reaction of ammonia with adsorbed oxygen species [5-9]. For α-MoO3, the charge depletion layer model predicts that the resistance of the film should decrease with increasing ammonia concentration. In addition to the charge depletion layer model, other sensing mechanisms have been suggested, such as the partial reduction by ammonia of the surface of the α-MoO3 film [1,2] and the formation of oxygen vacancies in the α-MoO3 lattice [3].The α-MoO3 film can be fabricated by a variety of methods, including sol-gel synthesis, ion beam deposition, hydrothermal synthesis, and flame spray pyrolysis [1-6]. In this work, the α-MoO3 film is fabricated using Reactive Spray Deposition Technology (RSDT) followed by annealing to develop crystallinity. The RSDT is a flame-based process that can be used for the fabrication of α-MoO3 films at a commercial scale. The initial development of ammonia sensors with RSDT-fabricated α-MoO3 films of varying morphology was presented at the 236th ECS Meeting as an oral presentation, “Ammonia-Sensing Properties of α-MoO3 Fabricated by Reactive Spray Deposition Technology (RSDT).” From these initial sensors, the sensor with the strongest response to ammonia was selected for further testing at concentrations between 0.1 ppm and 5 ppm ammonia in dry air at 400°C. These sensing results and the materials characterization of the sensor by SEM and XRD before and after 80 hours of continuous testing are reported in Ebaugh et al. [7] and are shown in Figures 1-3. In Figure 1, the sensing results among the three test cycles comprising the 80 hours of testing are quite repeatable; however, the results consistently depart from the prediction of the charge depletion layer model between 3 ppm and 5 ppm.To better explain this unexpected sensing behavior, additional electrochemical testing and materials characterization is needed. Specifically, normal pulse voltammetry (NPV) can be used to provide data pertaining to the electronic path through the α-MoO3 film and the reaction and transport of chemical species adsorbed on the α-MoO3 film. TEM analysis of the α-MoO3 can show the nanoscale morphology of the sensing material. It is well established that the nanoscale morphology of the metal-oxide film impacts its sensing behavior [8-10]. XPS can also be used to investigate the possible reduction of the surface of the α-MoO3 particles and the formation of oxygen vacancies in the α-MoO3 lattice. Data from the materials characterization of the sensing film (XRD, SEM, TEM, and XPS) will be used in conjunction with sensing results and NPV data to develop an explanation for the sensor behavior observed in [7]. An understanding of the ammonia-sensing mechanism will help to guide the optimization of the RSDT-fabricated α-MoO3 film to improve the performance of the sensor for a wide range of applications.References A. K. Prasad, et al. Thin Solid Films. 436 2003 pp. 46-51.P. Gouma, et al. IEEE Sensors Journal. 10 (1) 2010 pp. 49-53.A. K. Prasad, et al. Sensors and Actuators B: Chemical. 93 2003 pp. 25-30.P Gouma, et al. Journal of Breath Research. 5 2011 p. 037110.A. T. Güntner, et al. Sensors and Actuators B: Chemical. 223 2016 pp. 266-273.D. Kwak, et al. ACS Applied Materials & Interfaces. 11 2019 pp. 10697-10706.T. A. Ebaugh, et al. ACS Applied Materials & Interfaces. Under review.C. S. Rout, et al. Nanotechnology. 18 2007 p. 205504.M. E. Franke, et al. Small. 2 (1) 2006 pp. 36-50.N. Barsan, et al. Fresenius Journal of Analytical Chemistry. 365 1999 pp. 287-304. Figure 1

Validated UPLC-MS/MS Method for the Simultaneous Quantification of Vortioxetine and Fluoxetine in Plasma: Application to Their Pharmacokinetic Interaction Study in Wistar Rats

Short Retraction Notice The paper does not meet the standards of American Journal of Analytical Chemistry. The article has been retracted due to the conflicts of interests between all authors to straighten the academic record. Aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused. The full retraction notice in PDF is preceding the original paper, which is marked RETRACTED.

Study of Ultrasound-assisted Acid Hydrolysis to Obtain Quercetin and their Antioxidant Activities from some Plants

In this study, acidic hydrolysis to release the aglycone quercetin from plant extracts under ultrasound-assisted conditions was investigated. Based on the stability of quercetin, the suitable conditions were as follows: methanol/H2O (50:20, v/v) was added to the powder plants (ratio 50:1, ml/g), these mixtures were placed in ultrasonic bath of 37 kHz/550W; kept at 70°C within 30 min and then filtered. The filtrate was acidified with HCl (70:8, ml/ml). Lastly, the ultrasonication was carried out for hydrolysis for 1 hour (the second ultrasound) to obtain quercetin. We have obtained quercetin containing hydrolyzed extract from 10 plants to determine quercetin concentrations (using the HPLC optimized conditions) and evaluate the antioxidant activity (the capability to scavenge the DPPH radical). In 10 samples of plants that were obtained, both quercetin concentrations and antioxidant activity in the plant extract of the flower buds of Sophora japonica L have the highest value, then to the plant extract of Nelumbo nucifera Gaertn. In the Sophora flower-bud and the lotus leaf, quercetin content is calculated on dry material (mg/100g), 15423.04 and 5190.82 respectively; the average percentage inhibition of DPPH 100 µM (%) 55.26% and 32.23%., respectively.&#x0D; Keywords: Quercetin, HPLC, acid hydrolysis, ultrasound-assisted, antioxidant activity.&#x0D; References&#x0D; [1] S.G. Dmitrienko, V.A. Kudrinskaya, V.V. Apyari, Methods of extraction, preconcentration, and determination of quercetin, Journal of Analytical Chemistry 67 (4) (2012) 299-311. https://doi.org/ 101134/S106193481204003X.[2] H. Nishimuro, H. Ohnishi, M. Sato, M. Ohnishi-Kameyama, I. Matsunaga, S. Naito, K. Ippoushi, H. Oike, T. Nagata, H. Akasaka, S. Saitoh, K. Shimamoto, M. Konori, Estimated daily intake and seasonal food sources of quercetin in Japan, Nutrients 7 (4) (2015) 2345-2355. https://doi.org/ 10.3390/nu7042345.[3] C. Zhao, X. Ren, C. Li, H. Jiang, J. Guan, W. Su, Y. Li, Y. Tian, T. Wang, S. Li, Coupling ultrasound with heat-reflux to improve the extraction of quercetin, kaempferol, ginkgetin and sciadopitysin from Mairei Yew leaves, Applied Sciences 9 (4) (2019) 795-810. https://doi.org/10.3390/app9040795.[4] J. Azmir, M.S.I. Zaidul, M.M. Rahman, K.M. Sharif, A. Mohamed., F. Sahena, A.H.M. Jahurul, K. Ghafoor, N.A.N. Norulain, K.A.M. Omar, Techniques for extraction of bioactive compounds from plant materials : A review, Journal of Food Engineering 117 (4) (2013) 426-434. https://doi. org/10.1016/j.jfoodeng.2013.01.014.[5] L.H. Hoang, D.T.H. Anh, D.T. Hue, T.T.K. Oanh, N.Q. Huy, Determination of Quercetin Aglycone in Flos Sophorae japonicae Extract by High Performance Liquid Chromatography, VNU Journal of Science: Natural Sciences and Technology 33 (1S) (2017) 214-223 (in Vietnamese). https://doi.org/10.25073/2588-1140/ vnunst.4534. [6] A.M. Nuutila, K. Kammiovirta, M. Oksman-Caldentay, Comparison of methods for the hydrolysis of flavonoids and phenolic acids from onion and spinach for HPLC analysis, Food Chemistry 76 (4) (2002) 519-525. https://doi.org/ 10.1016/S0308-8146(01)00305-3.[7] L. Qiao, Y. Sun, R. Chen, Y. Fu, W. Zhang, X. Li, J. Chen, Y. Shen, X. Ye, Sonochemical effects on 14 flavonoids common in citrus : Relation to stability, Plos One 9 (2) (2014) e87766. https://doi. org/10.1371/journal.pone.0087766.[8] W. Brand-Williams, M.E. Cuvelier, C. Berset, Use of a free radical method to evaluate antioxidant activity, LWT - Food Science and Technology 28 (1995) 25-30. https://doi.org/10.1016/S0023-6438 (95)80008-5.&#x0D; [9] M. Biesaga, Influence of extraction methods on stability of flavonoids, Journal of Chromatography A 1218 (2011) 2505-2512. https://doi.org/10.1016/ j.chroma.2011.02.059.[10] L. Paniwnyk, E. Beaufoy, J.P. Lorimer, T.J. Manson, The extraction of rutin from flower buds of Sophora japonica, Ultrasonics Sonochemistry 8 (3) (2001) 299-301. https://doi.org/10.1016/S1350 -4177(00)00075-4.[11] X. He, Y. Bai, Z. Zhao, X. Wang, J. Fang, L. Huang, M. Zeng, Q. Zhang, Y. Zhang, Z. Zheng, Local and traditional uses, phytochemistry, and pharmacology of Sophora japonica L.: A review, Journal of Ethnopharmacology 187 (2016) 160-182. https://doi.org/10.1016/j.jep.2016.04.014.[12] I.Y. Bae, B.Y. Kwak, H.G. Lee, Synergistic antiradical action of natural antioxidants and herbal mixture for preventing dioxin toxicity, Food Science and Biotechnology 21 (2) (2012) 491-496. https://doi.org/10.1007/s10068-012-0062-9.

Open Journal of Analytical and Bioanalytical Chemistry

Busulfan (Bu) is an old drug, but is still well recommended as alkylating agent during the conditioning therapy, before hematopoietic stem cell transplantations (HSCT). Although its dose administrations are standardized and based on patients’ weight, the therapeutic drug monitoring (TDM) is required in order to maintain its exposure within a narrow therapeutic range and, if necessary, to adjust the dose.

Comparison of Selected Journal Quality Indicators of Analytical Chemistry Journals

Aim of this research study is to predict the correlation, if any, between the journal impact factor, SCImago ranking, Eigenfactor score and H-index of Analytical chemistry journals and quality of these journals. JIF is considered a good parameter for evaluation of scientific journals but has been criticized on many counts such as self-citation, limitation to English language etc. Seventy five (75) analytical chemistry journals indexed in WoS and Scopus databases were selected in this research for comparison of various indices. Correlations between indices (JIF, ES, SJR, and H-index) were evaluated using Pearson and Spearson’s correlation. Annual Review of Analytical Chemistry was at the top with JIF of 8.0 and the lowest for American Laboratory journal with JIF of 0.028. In case of SCImago ranking, Eigenfactor score and H-index, highest valued journals were reported as Annual Review of Analytical Chemistry (SJR = 3.078), Analytical Chemistry (ES = 0.1588) and Analytical Chemistry (H-index = 109). Lowest valued journals were reported as American Laboratory journal (SJR = 0.106), Archeosciences-Revue D Archeometrie (ES = 0.0001) and Instrumentation Science and Technology (H-index = 0). Throughout the study, none of the journals had the same ranking to compare different indicators. Pearson’s correlation between JIF and SJR values reached a high value (0.936) as compared to either ES (0.558) or H5 (0.567).

Biosensor/Biofuel Cell System for Lactate Detection in Sweat, Targeted Towards Human Performance

Non-invasive monitoring of biomarkers in biological fluids through the use of wearable sensors gained significant interest in the past several decades [1]. Research efforts have been focused on the development of chemical and biochemical sensors for a range of metabolites, including glucose, lactate, ethanol, trace metals and various ions, targeting several bodily fluids such as tears, saliva, and sweat [2]. Work presented here will discuss the development of a sensor system, capable of real-time monitoring of lactate levels in sweat. Such a device is desired in order to correlate increasing levels of lactate to fatigue levels of a person performing physically demanding activities [3]. Most existing systems employ traditional batteries as power sources for sensors. The system described here utilizes a light weight biofuel cell as the power source giving a complete bio-friendly sensor system. The system is comprised of three main elements: a biosensor, a biofuel cell, and electronics interface. The biosensor detects lactate levels in sweat via enzymatic reaction of Lactate Dehydrogenase (LDH). Sensor patch features a three electrode design assembled onto generic athletic tape and covered with medical gauze, providing both flexibility and sweat collection capability. LDH is immobilized at the working electrode via conductive carbon-based ink. The electrode surface is then further modified by vapor-deposited tetramethyl orthosilicate (TMOS) coating in order to provide greater stability to the sensor against temperature and pH fluctuations. Sensor calibration time period was relatively quick (5 minutes) and response was immediate with addition of lactate. Test results for the sensor patch showed an open circuit potential of ~0.06V vs. Ag/AgCl and an equilibrated current of approximately 30µA when held at 0.3V vs. Ag/AgCl. The patch also demonstrated a sensitivity of 0.2µA/mM lactate when tested in a range of 5-100mM lactate. A glucose-based biofuel cell provides the power to operate the biosensor. The anode, driving glucose oxidation, is comprised of immobilized Glucose Dehydrogenase (GDH) on a high surface area carbon felt (CF) electrode. Prior to enzyme immobilization, CF electrode surface was modified with electrochemically deposited polymethylene green (PMG) as well as chemically tethered Nicotinamide Adenine Dinucleotide (NAD). An oxygen-reducing cathode was employed as counter electrode. The biofuel cell generated an open circuit potential of 0.7V vs. Ag/AgCl, a total current of 81.0mA, and total power of 16.7mW. The patch sensor is coupled to the biofuel cell via external electrical components: an energy harvester and a micropotentiostat. The energy harvester component is connected to the biofuel cell. Its primary function is to continuously provide stable output voltage to the micropotentiostat. Thus it is constantly drawing power from the biofuel cell and up-converting the voltage from 0.7 to 3V. The patch sensor is connected to the micropotentiostat. A constant potential of 0.3V vs. Ag/AgCl is needed to operate the sensor, which is supplied by the micropotentiostat. Additionally, it is used to provide a read-out of an electrical signal, i.e. current, generated during sensor operation. System performance was demonstrated, employing artificial sweat. Results showed linear sensor response with increasing lactate content of the artificial sweat solution. [1] A. J. Bandodkar and J. Wang, "Non-Invasive Wearable Electrochemical sensors: A Review," Trends in Biotechnology, vol. 32, no. 7, pp. 363-371, 2014. [2] J. Kim, W. R. de Araujo, I. A. Samek, A. J. Bandodkar, W. Jia, B. Brunetti, T. R. Paixao and J. Wang, "Wearable temporary tattoo sensor for real-time trace metal monitoring in human sweat," Electrochemistry Communications, vol. 51, pp. 41-45, 2015. [3] S. Jadoon, S. Karim, M. R. Akram, A. K. Khan, M. A. Zia, A. R. Siddqi and G. Murtaza, "recent Developments in Sweat Analysis and Its Applications," International Journal of Analytical Chemistry, pp. 1-7, 2015. Figure 1

Determination of Antibiotic Drug Cefdinir in Human Plasma Using Liquid Chromatography Tandem Mass Spectroscopy

The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that there are conflicts of interests between the authors and their organization. The scientific community takes a very strong view on this matter, and the American Journal of Analytical Chemistry treats all unethical behavior seriously. This paper published in Vol. 6 No. 3 239-254, 2015 has been removed from this site. Title: Determination of Antibiotic Drug Cefdinir in Human Plasma Using Liquid Chromatography Tandem Mass Spectroscopy Author: Mohammad A. Al Bayyari, Raed S. Abu Ajjour