quantitative determination of volatile compounds

... analysis of samples to determine the weight percent of total volatile material, using US EPA Reference Methods 24/24A, ASTM D 2369-01 5.3.2 Determination of sample water content For determination of ... apply to the determination of the composition or concentration of fragrance components in products 1.4 The term “Executive Officer” as used in this document means the Executive Officer of the Air ... with the applicable VOC standards This determination may be used to establish a violation of ARB regulations 3.6 Determination of the LVP-VOC status of compounds and mixtures This section does...

Ngày tải lên: 14/03/2014, 20:20

... practices and determine the applicability of regulatory limitations prior to performing this test method 5.2 Hazardous Pollutants Several of the compounds, leaks of which may be determined by this method, ... published for the compounds of interest for the instrument or detector type, the response factor determination is not required, and existing results may be referenced Examples of published response ... concentration 3.2 Calibration precision means the degree of agreement between measurements of the same known value, expressed as the relative percentage of the average difference between the meter readings...

Ngày tải lên: 14/02/2014, 08:20

... procedures for determination of organic compounds in finished drinking water, source water, or drinking water in any treatment stage The method is applicable to a wide range of organic compounds that ... base, and generating a list of tentatively identified compounds with their retention times and scan numbers The software must also allow integration of the ion abundance of any specific ion between ... leach organic compounds into the eluting solvent One liter of water should pass through the cartridge in about two hours with the assistance of a slight vacuum of about 13 cm (5 in.) of mercury...

Ngày tải lên: 22/03/2014, 14:20

... threshold of volatiles, synergistic effect between volatiles and the interaction of non -volatile with volatile flavour compounds (Nisperos-Carriedo and 21 Shaw, 1990) The volatile compounds present ... number of species, and are more diverse than other citrus groups (Hodgson, 1967) As a result, various cultivars of mandarins have distinct profiles of volatile compounds even though all of them ... aromatic composition of foods is generally very complex and may consist of hundreds of compounds with various classes of functional groups Furthermore, different classes of compounds have different...

Ngày tải lên: 11/09/2015, 09:11

... has both volatile compounds and nonvolatile compounds including organic acids, sugars, vitamins, amino acids 2.1.2 Volatile compounds 2.1.2.1 Volatile compounds in longan juice Volatile compounds ... characteristic volatile compound in the raw fruit whereas other volatile compounds contribute to the flowery and sweet odor of the fruit 17 2.1.2.2 Analysis of volatile compounds in fruit juice Determination ... of wine quality Chapter is a review of literature on the nutritional compounds of longan (including non -volatile and volatile compounds) and the fermentation of longan juice to produce longan wine,...

Ngày tải lên: 08/11/2015, 17:24

... Martin Badertscher Structure Determination of Organic Compounds Tables of Spectral Data Fourth, Revised and Enlarged Edition 123 Prof Dr Ernăo Pretsch ETH Zăurich Institute of Biogeochemistry and Pollutant ... Spectra of Solvents and Reference Compounds ������������ 5.14.1 1H NMR Spectra of Common Deuterated Solvents����� 5.14.2 1H NMR Spectra of Secondary Reference Compounds ��� 5.14.3 1H NMR Spectrum of ... the xth isotope of element i, mix is the mass of the xth isotope of the element i, and the exponent ni stands for the number of atoms of the element i in the molecule The expansion of this polynomial...

Ngày tải lên: 07/05/2016, 22:46

... Quantification of 2-AP in pandan leaf: Fig System of the SPME extraction 732 Content of - AP in pandan leaf extracted by SDE was calculated as follows: Research on the Change of 2-AP and Other Volatile Compounds ... Investigating the changes of 2-AP and other volatile compounds of rice in Bun processing Table The volatile compounds in non-soaking and 12 hours soaking of Khao Dawk mali recorded by GCMS N 12 hours ... (milled rice), and Black rice (mixture of several varieties) For the identification and quantification of change in 2-AP and other volatile compounds, milled rice of KDM was soaked in water for 12...

Ngày tải lên: 28/08/2013, 16:28

... Two natural sources of benzene are volcanoes and forest fires Benzene is a natural part of crude oil, gasoline, and cigarette smoke Benzene is one of the major components of JP-8 fuel Industry ... moderate levels of trichloroethylene can get enlarged livers, and high levels of exposure can cause liver and kidney damage Studies of people exposed over long periods to high levels of trichloroethylene ... oil, gas, and coal, and from discharges of ethylbenzene from factories Ethylbenzene gets into the soil by spills of gasoline or other fuels and poor disposal of industrial and household wastes People...

Ngày tải lên: 14/02/2014, 03:20

... total of mg of curdione (1), mg of curcumol (2), 10 mg of germacrone (3), 18 mg of curzerene (4), mg of 1,8-cineole (5) and 17 mg of b-elemene (6) from the essential oil (300 mg) in 2.4 mL of the ... pulsation of the column because of elevated pressure [9] When revolution speed was 1200 rpm and flow rate of the mobile phase was 2.5 mL/min, more than 50% of the stationary phase (upper layer of petroleum ... increasing the volume ration of ethyl acetate result in the increasing of the K values of curdione (1), curcumol (2) and germacrone (3), and the decreasing of the K values of curzerene (4), 1,8cineole...

Ngày tải lên: 07/03/2014, 21:20

... Quantification of 2-AP in pandan leaf: Fig System of the SPME extraction 732 Content of - AP in pandan leaf extracted by SDE was calculated as follows: Research on the Change of 2-AP and Other Volatile Compounds ... Investigating the changes of 2-AP and other volatile compounds of rice in Bun processing Table The volatile compounds in non-soaking and 12 hours soaking of Khao Dawk mali recorded by GCMS N 12 hours ... (milled rice), and Black rice (mixture of several varieties) For the identification and quantification of change in 2-AP and other volatile compounds, milled rice of KDM was soaked in water for 12...

Ngày tải lên: 19/03/2014, 16:20

... and si are the values of wind direction and wind speed of sample i The ranges of wind direction and wind speed are divided into a series of subranges having similar numbers of samples in each Then ... overfitting of c13-benzene for the case of 10 sources Neither poor fit nor over fit is acceptable So the number of sources for this analysis was chosen to be During the experiments, FIGURE Profiles of ... model can be written as X ) GFT + E (1) where X is the matrix of VOCs’ concentrations, F is the matrix of source profiles, G is the matrix of source contributions, and E is the residuals matrix Their...

Ngày tải lên: 22/03/2014, 14:20

... the mechanical determination of the constituents of all substantive compounds indicates the type of qualitative and quantitative lexical information required for the planning of the capital memory ... Substantive Compounds A number of SC are characterized by what I call an “X-factor.” It is this occurrence of Xfactors which presents the main difficulty in the mechanization of the determination of the ... mechanical determination of the constituents of a SC is the occurrence or non-occurrence of the memory equivalent of an input form in the MT memory, such cases have to be considered in the solution of...

Ngày tải lên: 23/03/2014, 13:20

... 2370 E C Apel et al.: Chemical evolution of volatile organic compounds Fig 14 Results of a MM model run to test of the sensitivity of the model to specific compounds The model was initialized with ... evolution of volatile organic compounds Fig The top 20 compounds measured at T0 (top panel) and T1 (lower panel) in terms of mixing ratios between 09:00 and 18:00 local time averaged over the month of ... of volatile organic compounds Fig The top 20 compounds measured from T0 (top panel), T1 (middle panel) and the C130 platform (lower panel), in terms of OH reactivity averaged over the month of...

Ngày tải lên: 28/03/2014, 20:20

... of 5% was used to measure the significance between sample replicates Repeated measures analysis of variance was then used to test for the presence of interaction between the effects of Page of ... have investigated the suitability of 10 commonly used housekeeping genes for use as QPCR normalisers in a variety of cell types infected with a variety of strains of HIV-1, HSV-1, VZV and cytomegalovirus ... deviations of reference gene expression as determined by GeNorm are shown Abbreviations: Sumv: Sum of viral infection GeNorm values; sumRGC: sum of reference gene GeNorm values Table 3: Reliability of...

Ngày tải lên: 18/06/2014, 18:20

... observed shift of wavelength and the corresponding change of EOT signal are attributed to a change of the porous refractive index of nanoporous AAO layer as a result of the adsorption of H2S molecules ... H2S that arises from bacterial metabolism of amino acids and proteins is another example of biomedical determination of H2S that can be used for diagnosis of specific diseases [5] Oral malodour, ... the use of nanoporous anodic aluminium oxide [AAO] for reflective interferometric sensing of volatile sulphur compounds and hydrogen sulphide [H2S] gas Detection is based on changes of the interference...

Ngày tải lên: 18/06/2014, 22:20

... of 5% was used to measure the significance between sample replicates Repeated measures analysis of variance was then used to test for the presence of interaction between the effects of Page of ... have investigated the suitability of 10 commonly used housekeeping genes for use as QPCR normalisers in a variety of cell types infected with a variety of strains of HIV-1, HSV-1, VZV and cytomegalovirus ... deviations of reference gene expression as determined by GeNorm are shown Abbreviations: Sumv: Sum of viral infection GeNorm values; sumRGC: sum of reference gene GeNorm values Table 3: Reliability of...

Ngày tải lên: 20/06/2014, 01:20

... observed shift of wavelength and the corresponding change of EOT signal are attributed to a change of the porous refractive index of nanoporous AAO layer as a result of the adsorption of H2S molecules ... H2S that arises from bacterial metabolism of amino acids and proteins is another example of biomedical determination of H2S that can be used for diagnosis of specific diseases [5] Oral malodour, ... the use of nanoporous anodic aluminium oxide [AAO] for reflective interferometric sensing of volatile sulphur compounds and hydrogen sulphide [H2S] gas Detection is based on changes of the interference...

Ngày tải lên: 20/06/2014, 04:20

... observed shift of wavelength and the corresponding change of EOT signal are attributed to a change of the porous refractive index of nanoporous AAO layer as a result of the adsorption of H2S molecules ... http://www.nanoscalereslett.com/content/6/1/634 Page of Figure Schematic of the RIfS device for gas sensing Scheme of detection of VSCs using nanoporous Au-AAO reusable halves and sealed during use by fixing in a bondless microfluidic ... concentration of total sulphur compounds in the malodour of healthy individuals is between 0.2 to 0.4 µg/L [24] Detection of VSCs within these limits by the Au-AAO sensor confirms the high sensitivity of...

Ngày tải lên: 20/06/2014, 23:20

... while the concentration of higher alcohols was decreased (Additional file 1) Further characterisation of the effect of rehydration nutrients on the formation of volatile sulfur compounds was obtained ... YAN Figure Effects of nutrients addition on the final concentration of volatile sulfur compounds (A) and polyfunctional thiols (B) Nutrient treatments included supplementation of rehydration nutrients ... induced the formation of H2S while the addition of DAP delayed it Page of 11 (Figure 1c) Nonetheless, these results support our previous hypothesis of distinct effects for each of the treatments...

Ngày tải lên: 20/06/2014, 23:20