• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.70-75
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• 2011

A new and improved analytical method involving alkaline pyridine extraction was proposed to quantity chlorophyll contents in syrup and candy type chlorella products. The performance of analytical method was compared with the conventional Korea food standard method which involves acetone extraction. The application of sonication chlorophyll extraction form alkaline pyridine sample was also explored. The analytical procedure was validated by evaluating accuracy, precision and reproducibility. For liquid samples, the pyridine extraction method showed higher accuracy and precision compared to acetone extraction method. The CV values of pyridine extract method and the acetone extraction method were 18.82 and 40.0, and the accuracy to theoretical values were 106.3% and 78.1%, respectively. When sonication extraction method was applied to the pyridine extraction, the precision was improved as indicated by reduced CV values from 18.82 to 11.36. The improved performance of pyridine-sonication extraction was also validated by recovery test of chlorophyll that was previously spiked into the sample matrix. For solid matrix, the pyridine extraction method showed better performance in analysis of chlorophyll in solid food matrix (CV = 7.05) compared to conventional acetone extraction method (CV = 30.0). However, the accuracy to theoretical values of pyridine and acetone extraction methods only showed only 62.7% an 40%, respectively. The relatively low accuracy of pyridine extraction method (62.7%) was improved to 99.4% by applying additional sonication extraction method. The improved performance of applying additional sonication extraction was validated by standard deviation, CV values and accuracy to theoretical values.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.704-708
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• 2015

For the analysis of multiple-reaction intermediates for long-chain dicarboxylic acid biotransformation, simple and reproducible methods of extraction and derivatization were developed on the basis of gas chromatography with flame ionization detector (GC-FID) instead of mass spectrometry. In the derivatization step, change of the ratio of pyridine to MSTFA from 1:3 to 9:1 resulted in higher peak intensity (p = 0.021) and reproducibility (0.6%CV) when analyzing 32 g/l ricinoleic acid (RA). Extraction of RA and ω-hydroxyundec-9-enoic acid with water containing 100 mM Tween 80 showed 90.4-99.9% relative extraction efficiency and 2-7%CV compared with those with hydrophobic ethyl acetate. In conclusion, reduction of the pyridine content and change of the extraction solvent to water with Tween 80 provided compatible derivatization and extraction methods to GC-FID-based analysis of longchain carboxylic acids.

• Archives of Pharmacal Research
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• v.5 no.2
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• pp.71-77
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• 1982

Improvements in the analytical methodology used in the gas chromatographic/mass spectral analysis of phenolic compounds from cigarette smoke are described. For the direct analysis of crude samples, pyridine extraction and the glass capillary column GC was used for the separation of phenolics as trimethylsilyl derivativatives. The separations of cigarette smoke on Carbowax 20M and SE-54 wall coated open tubular columns are given. Improved methodology for the routine quantitation of the identified components using the computer-controlled multiple ion selection technique of MS presented. Considerations pertaining to routine analyses of a multitude of complex smoke samples are also discussed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.1
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• pp.25-33
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• 2008

A selective separation of Actirlide(III) by a nPr-BTP/nitrobezene extraction system was studied. The nPr-BTP (2.6-Bis-(5.6-n-propyl-1.2.4-triazin-3-yl)-pyridine) of a environmentally -friendly CHN type was self-synthesized and its compatability with diluent and stability with nitric acid were investigated. At the 0.1M nPr-BTP/nitrobenzene-1M $HNO_3$ and O/A=2, extraction yields of Am used as a representative of Actinide(III) and Eu were about 85% and 8%, respectively, and the other RE elements such as Nd, Ce and Y were extracted less than 3% (separation factor of Am and Eu was about 60). Thus, there was no problems in the selective extraction of Actinide(III) from RE. The stripping yield of Am with 0.05M $HNO_3$ at O/A= 1, however, was about 43% and the maximum stripping yield was 65% at O/A=0.3. It is necessary to develop the stripping system including the stripping agent instead of nitric acid solution.

• Analytical Science and Technology
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• v.9 no.4
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• pp.399-405
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• 1996

The flavor compounds of the oil from roasted sesame seeds were collected by simultaneous steam distillation/ extraction(SDE) and dynamic headspace sampling(DHS) and were analyzed using a gas chromatograph equipped with a flame ionization detector and connected into a mass spectrometer. Among the flavor compounds collected by the SDE method, 46 compounds were identified. They consisted of 6 alcohols, 6 aldehydes, 5 ketones or acids, 4 furans or phenols, 12 pyrazines, 4 pyridines or thiazoles, and others. Thirty six compounds were identified by DHS and many of them were the same as those identified by the SDE method. However, some compounds such as 1-hexanol, pentanal, and dimethylsulfide were identified only by the DHS method.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.596-602
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• 2014

Dutch coffee is extracted in low temperature for a longer time than espresso and drip coffee. This study was conducted to investigate changes in the flavor compounds in Dutch coffee resulting from different extraction times and storage days. The fifty six flavor compounds in Dutch coffee were identified using a headspace mass-spectrometer. Major flavor compounds were 2-furfuryl acetate, 5-methylfurfural, pyridine, furfural, 2-acetylfuran, pyridine, 2-methoxyphenol, furfuryl alcohol and some compounds varied with espresso and drip coffee. It was worthy of notice that more diverse compounds were composed of total flavor in Dutch coffee. There were more kinds of flavor compounds in early extracts than in latter ones. The duration of storage didn't significantly affected the peak area percentage of flavor compounds in Dutch coffee except with 2-furfuryl acetate.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.170-173
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• 1963

A tri-thiocyanate molybdenum (Ⅴ) complex containing pyridine has been prepared by one step process; namely, the solvent extraction of molybdenum (Ⅴ)-thiocyanate complex into organic solvents followed by precipitation of the compound by addition of pyridine to the extract. It is concluded that the compound has a definite composition regardless of the various mole ratios of molybdenum to thiocyanate ion employed in the preparation. The use of hydrazine as the reducing agent eliminates the necessity of working under inert atmosphere and of further purification of the product. Molybdenum (Ⅴ)-thiocyanate (1:3) complex can be quantitatively and selectively extracted with slightly polar organic solvents such as ethyl acetate, and the pyridine complex is quantitatively obtained due to the insolubility of the compound in them. The oxidation state of molybdenum in the compound is + 5 and the formula appears to be $MoH_2O_2(NCS)_3Py_2$ from the contents of Mo and NCS in the compound. The solubility of the compound in various has been studied at $25^{\circ}C$.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.160-167
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• 1998

Chemical studies of nitrogen compounds of Panax ginseng seem relatively rare, Probably due to the isolation difficulties, subsequently the investigations of biological activities are little. The experimental conditions were established for highly complete extraction of peptides (basic, acidic and neutral) from Panax ginseng. This task was achieved by applying the follow isolation procedure: 1 , the sequential extraction with water, 0.1% TFA in 20% acetonitril and buffer pH 6.5 (water-pyridine-acetic acid 100:3:900) : 2, fractionation by ultrafiltration : 3, n-butanol extraction 4, cation- and anion-exchange chromatography : 5, chromato-electrophoresis. The comparison of red ginseng (xylem Sl pith part) and red ginseng inside white (xylem Sc pith part) was also provided. To analyze the peptide mixture the chromato-electrophoresis method of separation was applied. Optimal conditions for peptides mapping of sample were explored. Our experiments revealed the quantitative difference of peptide between xylem & pith and phloem & cortex part. We have also found the qualitative difference in the composition of polypeptides between normal red ginseng (xylem Sc pith part) and red ginseng inside-white (xylem St pith part)

• YAKHAK HOEJI
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• v.13 no.1
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• pp.28-32
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• 1969

For the colorimetric determination of Sulfa-drugs by means of solvent extraction, the sample solutions were added into dimethylglyoxime-Fe(II) complex solution, and extracted with pyridine-chloroform mixture (1:50) is a range of pH 7.5-8.5. The extracted solution shows stability and maximum absorption at 402m${\mu}$.

• YAKHAK HOEJI
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• v.13 no.1
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• pp.22-27
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• 1969

Nicotinamide Complex Compound was not formed in simple alkaline solution under two to one molar ratio of dimethyglyoxime and Fe (II), but it was formed with ammonia or pyridine under the same molar ratio. Based on this fact, nicotinamide solution was added into dimethyglyoxime-Fe (II) complex solution, and the chelation product was extracted with chloroform. The extraction was Completed in a range of pH 8.4-11.0. The chloroform solution shows stability and maximum absorption at 516 m${\mu}$.