liquid solid or solid phase extraction

... 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...

Ngày tải lên: 17/09/2015, 17:20

... 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...

Ngày tải lên: 16/09/2015, 17:13

... 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...

Ngày tải lên: 16/09/2015, 17:13

... 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...

Ngày tải lên: 16/09/2015, 17:13

... 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...

Ngày tải lên: 16/09/2015, 17:13

... 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...

Ngày tải lên: 16/09/2015, 17:13

... 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...

Ngày tải lên: 16/09/2015, 17:13

... 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...

Ngày tải lên: 11/09/2015, 14:27

Ngày tải lên: 17/02/2014, 20:20

... 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...

Ngày tải lên: 08/03/2014, 18:20

... 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,...

Ngày tải lên: 09/08/2014, 20:22

... 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 ∈...

Ngày tải lên: 21/06/2014, 01:20

... 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...

Ngày tải lên: 14/12/2013, 00:41

... 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...

Ngày tải lên: 18/12/2013, 10:04

... 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...

Ngày tải lên: 22/12/2013, 12:59

... 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...

Ngày tải lên: 14/02/2014, 22:20

... 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...

Ngày tải lên: 17/02/2014, 22:20

... 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...

Ngày tải lên: 19/02/2014, 17:20

... 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...

Ngày tải lên: 26/02/2014, 20:20