A new chromatographic instrument for measuring trace concentrations of breath-hydrogen

Background: Soybean is rich in dietary fibers; consequently, soybean ingestion considerably increases the breath level of hydrogen molecules via anaerobic colonic fermentation. However, the influence of cooking methods on this effect, which can affect the overall health benefits of soybean, remains unknown. Objectives: The aim is to examine whether different methods of cooking soybean affect the colonic fermentation process. Methods: Nine healthy adult volunteers participated in the study; they ingested either roasted soybean flour (kinako) or well-boiled soybean (BS). Differences in their breath components were compared. Both test meals were cooked using 80 g of soybeans per individual. After a 12 h fast, the participants ate the test meals, and their breath hydrogen level was analyzed every 1 h for 9 h by using a gas chromatograph with a semiconductor detector. In addition, particle size distribution and soluble/ insoluble fibers in the feces were examined. Results: The oro-cecal transit time did not significantly differ between individuals who ingested kinako and BS. However, the area under the curve between 7 and 9 h after the ingestion of BS was significantly increased compared with that after the ingestion of kinako. The nutritional analysis indicated that the content of both soluble and insoluble fibers in BS was higher than that in kinako. In addition, the levels of unfermented fragments and soluble/insoluble fibers in the feces were increased after the ingestion of kinako compared with those after the ingestion of kinako. Conclusion: Cooking methods alter the composition of non-digestible fibers in soybean, and this can result in the lack of fermentative particles in the feces, thereby causing alterations in the breath level of hydrogen via colonic fermentation.

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Determination of trace concentrations of copper by FIA-FAAS after preconcentration on chelating sorbents

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19891785 ◽

1989 ◽

Vol 54 (7) ◽

pp. 1785-1794 ◽

Cited By ~ 7

Author(s):

Vlastimil Kubáň ◽

Josef Komárek ◽

Zbyněk Zdráhal

Keyword(s):

Sampling Frequency ◽

Copper Determination ◽

Flow Rates ◽

Sample Injection ◽

Injection Flow ◽

Chelating Sorbents ◽

Set Up ◽

Trace Concentrations ◽

Better Than

A FIA-FAAS apparatus containing a six-channel sorption equipment with five 3 x 26 mm microcolumns packed with Spheron Oxin 1 000, Ostsorb Oxin and Ostsorb DTTA was set up. Combined with sorption from 0.002M acetate buffer at pH 4.2 and desorption with 2M-HCl, copper can be determined at concentrations up to 100, 150 and 200 μg l-1, respectively. For sample and eluent flow rates of 5.0 and 4.0 ml min-1, respectively, and a sample injection time of 5 min, the limit of copper determination is LQ = 0.3 μg l-1, repeatability sr is better than 2% and recovery is R = 100 ± 2%. The enrichment factor is on the order of 102 and is a linear function of time (volume) of sample injection up to 5 min and of the sample injection flow rate up to 11 ml min-1 for Spheron Oxin 1 000 and Ostsorb DTTA. For times of sorption of 60 and 300 s, the sampling frequency is 70 and 35 samples/h, respectively. The parameters of the FIA-FAAS determination (acetylene-air flame) are comparable to or better than those achieved by ETA AAS. The method was applied to the determination of traces of copper in high-purity water.

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Laser optoacoustic detection of trace concentration levels of ethylene, vinylchloride, and styrene in the atmosphere

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19892667 ◽

1989 ◽

Vol 54 (10) ◽

pp. 2667-2673 ◽

Cited By ~ 5

Author(s):

Vojtěch Steiner ◽

Pavel Engst ◽

Zdeněk Zelinger ◽

Milan Horák

Keyword(s):

Detection Limit ◽

Emission Line ◽

Laser Line ◽

Laser Source ◽

Trace Concentration ◽

Selective Determination ◽

Hygienic Standard ◽

Trace Concentrations ◽

Concentration Levels

The optoacoustic analyzer with a tunable CO2 laser source employed in the present work permits a selective determination of ethylene in trace concentrations higher than 5 ppb (=detection limit for the 10P(14) emission line of the CO2 laser, ν = 949.5 cm-1) and of vinylchloride higher than 42 ppb (= detection limit for the 10P(22) CO2 laser line, ν= 942.4 cm-1). this method covers for both compounds the concentration range corresponding to the hygienic standard. It can be also used for the determination of styrene vapour with concentrations higher than 1.5 ppm.

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Transformation of Contaminants of Emerging Concern (CECs) during UV-Catalyzed Processes Assisted by Chlorine

Catalysts ◽

10.3390/catal10121432 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1432

Author(s):

Edyta Kudlek

Keyword(s):

Hydrogen Peroxide ◽

Water Samples ◽

Water Environment ◽

Toxicity Assessment ◽

Contaminants Of Emerging Concern ◽

Post Processing ◽

Processing Water ◽

Living Organisms ◽

Trace Concentrations ◽

By Products

Every compound that potentially can be harmful to the environment is called a Contaminant of Emerging Concern (CEC). Compounds classified as CECs may undergo different transformations, especially in the water environment. The intermediates formed in this way are considered to be toxic against living organisms even in trace concentrations. We attempted to identify the intermediates formed during single chlorination and UV-catalyzed processes supported by the action of chlorine and hydrogen peroxide or ozone of selected contaminants of emerging concern. The analysis of post-processing water samples containing benzocaine indicated the formation of seven compound intermediates, while ibuprofen, acridine and β-estradiol samples contained 5, 5, and 3 compound decomposition by-products, respectively. The number and also the concentration of the intermediates decreased with the time of UV irradiation. The toxicity assessment indicated that the UV-catalyzed processes lead to decreased toxicity nature of post-processed water solutions.

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The Daytime Breath Hydrogen Profile in Children with Abdominal Symptoms and Diarrhoea

Acta Paediatrica ◽

10.1111/j.1651-2227.1986.tb10263.x ◽

1986 ◽

Vol 75 (4) ◽

pp. 632-638 ◽

Cited By ~ 3

Author(s):

C. M. F. KNEEPKENS ◽

C. M. A. BIJLEVELD ◽

R. J. VONK ◽

J. FERNANDES

Keyword(s):

Breath Hydrogen ◽

Abdominal Symptoms

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Resistant starch in the diet increases breath hydrogen and serum acetate in human subjects

American Journal of Clinical Nutrition ◽

10.1093/ajcn/61.4.792 ◽

1995 ◽

Vol 61 (4) ◽

pp. 792-799 ◽

Cited By ~ 65

Author(s):

J G Muir ◽

Z X Lu ◽

G P Young ◽

D Cameron-Smith ◽

G R Collier ◽

...

Keyword(s):

Resistant Starch ◽

Human Subjects ◽

Breath Hydrogen

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Removal of trace contaminants using molecularly imprinted polymers

Water Science & Technology ◽

10.2166/wst.2006.354 ◽

2006 ◽

Vol 53 (11) ◽

pp. 205-212 ◽

Cited By ~ 16

Author(s):

M. Le Noir ◽

B. Guieysse ◽

B. Mattiasson

Keyword(s):

Activated Carbon ◽

Molecularly Imprinted Polymers ◽

The Other ◽

Molecular Imprinted Polymers ◽

Molecularly Imprinted ◽

Imprinted Polymers ◽

Trace Contaminants ◽

High Concentrations ◽

Trace Concentrations ◽

Granulated Activated Carbon

This work was conducted to study the potential of molecularly imprinted polymers (MIPs) for the removal of oestradiol at trace concentrations (1 ppm–1 ppb). An MIP synthesised with 17β-oestradiol as template was compared to non-imprinted polymers (NIP) synthesised under the same conditions but without template, a commercial C18 extraction phase and granulated activated carbon. At 1 ppb oestradiol was recovered by 98±2% when using the MIP, compared to 90±1, 79±1, and 84±2% when using the NIP, a C18 phase, or granulated activated carbon, respectively. According to these levels, the MIP was capable of producing an effluent with a quality 5–10 times higher than the other materials. The same levels of oestradiol recovery were achieved with the MIP when supplying 17β-oestradiol at 0.1 ppm. Phenolic compounds added as interferences bound less to the MIP than to the NIP, confirming the selectivity of the MIP. Oestradiol biodegradation was also demonstrated at high concentrations (50 ppm), showing the pollutants can be safely destructed after being enriched by molecular extraction. This study demonstrates the potential of molecular imprinted polymers as a highly efficient specific adsorbent for the removal of trace contaminants.

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