liquid solid or solid phase extraction
Development and application of liquid phase microextraction techniques in the analysis of environmental pollutants
... abbreviations SPME solid- phase microextraction LPME liquid- phase microextraction LPME/HF liquid- phase microextraction with hollow fiber LLLME liquid- liquid -liquid microextraction LLE liquid- liquid extraction ... fiber combination with liquid- phase microextraction It can be categorized into two- ii phase microextraction, and three -phase microextraction or liquid- liquid -liquid microextraction (LLLME) By ... prior to HPLC analysis, many methods have been developed such as liquid- liquid extraction (LLE), solid- phase extraction (SPE), solid- phase microextraction (SPME) and more recently solvent microextraction...
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Investigation and application of liquid chromatography mass spectrometry in the analysis of polar, less volatile and thermal unstable organic pollutants in environmental and biological samples 6
... Orthogonal array design was employed to optimize both microwave-assisted extraction and supercritical fluid extraction conditions for extracting carbamates (propoxur, ... Therefore, both MAE and SFE are suitable techniques for extracting carbamate pesticides from soil However, when extraction is from time-aged soil, MAE exhibited better recoveries than SFE Liquid ... as neither evaporation losses nor propoxur decomposition was observed during the process The extracts of goldfish, tortoises and sea lettuce were stable and a 3-days delay prior to analysis was...
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Investigation and application of liquid chromatography mass spectrometry in the analysis of polar, less volatile and thermal unstable organic pollutants in environmental and biological samples 5
... target According to our mode designed earlier, the four important variables selected for optimizing MAE are: (1) extraction solvents (factor A), (2) extraction temperature (factor B), (3) extraction ... 60οC 20 ml II Dichloromethane 80οC 30 ml Extraction Level species settings Goldfish and Tortoises Sea lettuce #: Dummy factor *A: Extraction solvent; B: Extraction temperature; C: Extraction time; ... optimization of extraction from sea lettuce Factor A, factor B, and factor D are statistically significant at p < 0.1, whereas the effects of factor C and interaction (B х C) are less important Minor differences...
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Investigation and application of liquid chromatography mass spectrometry in the analysis of polar, less volatile and thermal unstable organic pollutants in environmental and biological samples 4
... 4-10, factor A (extraction solvent), factor B (extraction temperature), factor C (extraction time) and the two-variable interaction B х C (interaction between extraction temperature and extraction ... the MAE extraction vessel, which contained 2.0 g of spiked soil sample Extraction was performed at 115°C with a heating time of for PAHs and PCBs, or for triazines at 80% power After the extraction, ... satisfactory extraction of propoxur since extremely high recoveries (101% and 98%, respectively) are obtained SFE shows slightly higher recovery for chlorpropham (93% vs 87% for MAE) For extraction...
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Investigation and application of liquid chromatography mass spectrometry in the analysis of polar, less volatile and thermal unstable organic pollutants in environmental and biological samples 3
... wavelength of 225 nm) and LC-APCI-ITMS 3.2.2 Preconcentration by Liquid- Liquid Extraction Liquid- liquid extraction with dichloromethane was used for concentrating propoxur and its TPs from the water samples ... 20-ml portions of dichloromethane After each successive extraction the organic layer was decanted All the organic fractions were combined, and evaporated to dryness in a rotary evaporator ml of ... degradation in both waters can be of importance, which affects the degradation positively, as reported for Carbaryl [17] Furthermore, degradation behavior in drinking water was quite similar to...
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Investigation and application of liquid chromatography mass spectrometry in the analysis of polar, less volatile and thermal unstable organic pollutants in environmental and biological samples 2
... grinded in a mortar and pestle with liquid nitrogen until a homogenous fine powder was obtained In order to meet the fortification standards for recovery and analytical precision, a portion of each ... (Bellefonte, PA, USA) or Ultra-Scientific (North Kingston, RI, USA) The stock standard solutions were prepared in acetone at concentrations of 2.0 mg/ml for each compound and stored at - 4°C Working solutions ... (Millipore, Bedford, MA, USA) water purification system All the samples (solutions and extracts) were filtered through 0.45-m membranes (Millipore) and degassed in an ultrasonic bath before use...
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Investigation and application of liquid chromatography mass spectrometry in the analysis of polar, less volatile and thermal unstable organic pollutants in environmental and biological samples 1
... immiscible phases: a liquid mobile phase and a stationary phase bed through which the liquid mobile phase passes The chromatographic process occurs as a result of repeated sorption/desorption steps ... after extraction In recent years, some novel extraction techniques for solid matrices such as supercritical fluid extraction (SFE), microwave-assisted extraction (MAE) and accelerated-solvent extraction ... method for liquid introduction into an MS Additionally, ESI is especially suited for the analysis of compounds ionized in the liquid phase, due to the fact that, the observed ions, generally formed...
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Applications of capillary electrophoresis in the analysis of natural products
... detector is also crucial for improving the sensitivity The most commonly used detector applied for CE is UV detector, but many components not show enough response due to their weak UV adsorption ... Introduction 1.1 Principles and historical perspective of Capillary Electrophoresis Since the introduction of capillary electrophoresis (CE) in 1980s by Jorgenson, the good performance and relatively simple ... (hydrophillicity or charge) Stability often problematic Table 1.2 Different Modes of High Performance Capillary Electrophoresis CE Mode Capillary zone electrophoresis (CZE) Capillary gel electrophoresis...
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Báo cáo khoa học: "PARSING VS. TEXT PROCESSING IN THE ANALYSIS OF DICTIONARY DEFINITIONS" pot
... that wordrelation-word triples are not adequate, or at least not optimal, for expressing all the useful information associated with words Some information is best expressed us unary attributes or ... each one its part or parts of speech (A run-on is a subentry, giving information about a word or phrase derived from the entry word or phrase; for instance, W7 part of speech categories (the others ... make and move had such consistent forms that the core word or words in the object or complement phrase were easy to identify Occasional prepositional phrases or other posmominal constructions...
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Báo cáo y học: "Computational challenges in the analysis of ancient DNA" ppsx
... analysis, we not use a correction for multiple substitutions Since our goal is to quantify the effects of various sources of error, the interaction between these errors and more refined pairwise ... position produce two or more alignments to the human genome whose bitscores differ by less than points (Figure S3 in Additional file 1) Therefore, requiring a minimum distance in bitscore between the ... recovering more sequences for the analysis, a more closely related genome sequence also gives a more complete picture of the ancient genome by avoiding a bias against highly diverged regions Correspondingly,...
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Báo cáo hóa học: " Some new nonlinear integral inequalities and their applications in the qualitative analysis of differential equations" potx
... for t Î p R+, then Corollary reduces to Theorem A [9, Theorem 2.1] If a(t) ≡ C p−q, m1(t) ≡ 1, g1(t) ≡ 0, l1(t) ≡ 0, m2(t) ≡ 1, n2(t) = l2(t) ≡ for t Î R+, then Corollary 2.1 reduces to Theorem ... Motivated by Corollary 2.2 and Theorem C [10], we will give the following more general theorem: Theorem 2:2: Assume that f(s, t), g(s, t), h(s, t) Î C(R+ × R+, R+) are nondecreasing in t for each s ... in [10], the author provided a more general result Theorem C: R+ = [0, ∞), R+ = (0, ∞) Let f(t, s) and g(t, s) ∈ C(R+ × R+ , R+ ) be nonde0 0 creasing in t for every s fixed Moreover, let φ ∈...
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A discourse analysis of presuppositions in the declaration of independence made by president ho chi minh = phân tích diễn ngôn các tiền giả định trong tuyên ngôn độc lập của chủ tịch hồ chí minh
... linguistic texts are explored in the study of discourse These might be in either spoken or written form, including a conversation or a letter, a speech or a report, a broadcast or an interview, a lesson, ... September 2, 1945 catches the author’s attention The author’s choice, firstly, originates from her feelings of honor and gratitude toward a preeminent leader of the nation Moreover, the independence ... context, written language is used for communication among people who are removed in time and space or for occasions requiring a permanent or semi-permanent record Meanwhile, most people in different...
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An analysis of errors made by high school student in the use of subject verb agreement in english writing = phân tích lỗi sai của học sinh PTTH về sự tương hợp giữa chủ ngữ và động từ trong văn viết tiếng anh
... Identification of error Description of errors Explanation of errors Evaluation of errors Prevention of errors 1.2.4 Causes of errors In fact, foreign language learners make a number of errors in the process ... refers to a singular unit or individual members Hence, it results in error in subject- verb agreement 1.2 Error correction [ (1) Should learners' errors be corrected? Error correction is said to be ... of errors committed in section Intralingual errors stand at 223(137+ 86), accounting for 60.2% They take a much bigger proportion than interlingual errors (only 29 errors or 7.8%) 2.7.3 Errors...
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The analysis of theme and rheme in little house on the prairie = sự phân tích về đề ngữ và thuyết ngữ, thông qua truyện ngôi nhà nhỏ trên thảo nguyên
... Prague work According to Halliday (1994), information consists of two categories: given information or just the given and new information or just the new Halliday suggests that New information ... Type co-ordinator Examples and, or, nor, either, neither, but, yet, so, then 27 subordinator when, while, before, after, until, because, if, although, unless, since, that, whether, (in order) ... the stress or pitch prominence As stated in Clark & Clark (1977:93), "sentences signal given and new information by stress or accent on particular words The words with the focal stress, or a phrase...
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Tài liệu Báo cáo khoa học: A systems biology approach for the analysis of carbohydrate dynamics during acclimation to low temperature in Arabidopsis thaliana doc
... authors and readers, this journal provides supporting information supplied by the authors Such materials are peer-reviewed and may be re-organized for online delivery, but are not copy-edited or ... Klotke et al [12] reported such a correlation for C24 and Col-0, which has a freezing tolerance similar to that of [6] Given that starch plays an important role as a major integrator in the regulation ... electrode For starch extraction, pellets for ethanol extraction were solubilized by heating them to 95 °C in 0.5 m NaOH for 30 After acidification with m CH3COOH, the suspension was digested for h with...
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Tài liệu A REVIEW OF INDOOR AIR POLLUTION AND HEALTH PROBLEMS FROM THE VIEWPOINT OF ENVIRONMENTAL HYGIENE: FOCUSING ON THE STUDIES OF INDOOR AIR ENVIRONMENT IN JAPAN COMPARED TO THOSE OF FOREIGN COUNTRIES pptx
... irritability, or nervousness,” “pain or stiffness in the back, shoulders, or neck,” “stuffy or runny nose, or sinus congestion, “sneezing,” “sore or dry throat,” “difficulty remembering things or with ... Odor The application of semiconductor-based odor sensors can evaluate indoor air quality by measuring formaldehyde and VOCs levels in low concentrations in residential spaces.125) A moldy order ... indoor air is a fundamental right for people studying in schools, working in offices and living in residences Indoor air quality plays an important role in the health of residents Many factors...
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Tài liệu Aesthetic preferences and the attribution of meaning: Environmental categorization processes in the evaluation of urban scenes ppt
... definition, the normal function and /or use of the place, and the age of the site and its upkeep) form additional bases for the perceptive-evaluative categorization made by nonexpert individuals (for a review ... perceptive-evaluative categories for urban scenes that were important for users: (1) historicalcultural landscapes, (2) leisure areas, (3) recreational landscapes, and (4) housing areas These categories were ... three categories mentioned form 96% of the visually most attractive places; the last two groupings form the majority of the settings considered most unattractive Three categories (historical-cultural...
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Tài liệu STRATEGIC ENVIRONMENTAL ASSESSMENT on shrimp farms in the southeast of Thailand docx
... due to incorrect fishery gear like explosives and poisons for fishing Other activities damaging the coral reefs are tourist boats using the reefs for anchorage and breaking the corals for souvenirs ... hypochlorite, that are added to the natural water may react with organic substances and create chlorinated compounds Chloramines, that are produced when chlorine reacts with ammonia, and organochlorine ... chlorine residuals The chlorinated hydrocarbons are probably formed after a chlorination process of water, which contains organic matter The free residual chlorine and 25 combined residual chlorine...
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The analysis of AHAs in cosmetic
... cosmetic products by solid- phase extraction and reversed -phase ion-pair highperformance liquid chromatography J Chromatogr A 795: 219-225 13 Skelly, N E 1982 Separation of inorganic and organic anions ... ACKNOWLEDGEMENTS We thank Taiwan Shiseido Corporation for offering their blank cream and Taiwan Avon Corporation for their fruit acid cosmetics We thank Mr L W Yang for his trans- 99 50 b 40 40 30 citric ... R., Wrolstad, R E and Cornwell, C J 1982 Comparison of enzymic, gas -liquid chromatographic, and high performance liquid chromatographic methods for determining sugars and organic acid in strawberries...
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Tìm thêm: xác định các nguyên tắc biên soạn khảo sát các chuẩn giảng dạy tiếng nhật từ góc độ lí thuyết và thực tiễn khảo sát chương trình đào tạo của các đơn vị đào tạo tại nhật bản khảo sát chương trình đào tạo gắn với các giáo trình cụ thể xác định thời lượng học về mặt lí thuyết và thực tế điều tra với đối tượng sinh viên học tiếng nhật không chuyên ngữ1 khảo sát các chương trình đào tạo theo những bộ giáo trình tiêu biểu nội dung cụ thể cho từng kĩ năng ở từng cấp độ xác định mức độ đáp ứng về văn hoá và chuyên môn trong ct phát huy những thành tựu công nghệ mới nhất được áp dụng vào công tác dạy và học ngoại ngữ mở máy động cơ lồng sóc các đặc tính của động cơ điện không đồng bộ hệ số công suất cosp fi p2 đặc tuyến hiệu suất h fi p2 đặc tuyến tốc độ rôto n fi p2 động cơ điện không đồng bộ một pha sự cần thiết phải đầu tư xây dựng nhà máy thông tin liên lạc và các dịch vụ từ bảng 3 1 ta thấy ngoài hai thành phần chủ yếu và chiếm tỷ lệ cao nhất là tinh bột và cacbonhydrat trong hạt gạo tẻ còn chứa đường cellulose hemicellulose chỉ tiêu chất lượng theo chất lượng phẩm chất sản phẩm khô từ gạo của bộ y tế năm 2008