Sensitive Determination of Dissolved Tryptophan in Freshwater by Alkaline Hydrolysis and HPLC

Wu, Fengchang; Tanoue, Eiichiro

doi:10.2116/analsci.17.1063

Cited by 24 publications

(16 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is likely that the change of monitoring section between the two MiniFluo generation has led to a decrease in the calibration error. Trp-like fluorophore concentrations measured with the MiniFluo in the present work (0-6 µg L −1 ) are higher than concentrations of total (free + combined) dissolved Tryptophan determined by alkaline hydrolysis and HPLC in coastal marine waters (0.2-0.4 µg L −1 ; derived from Yamashita and Tanoue, 2003) but close to those observed in freshwaters (2-8.5 µg L −1 ; derived from Wu and Tanoue, 2001). Two assumptions can be made to explain why the MiniFluo provides higher concentrations.…”

Section: Confidence In Minifluo Measurementscontrasting

confidence: 44%

A New Glider-Compatible Optical Sensor for Dissolved Organic Matter Measurements: Test Case from the NW Mediterranean Sea

Cyr

Tedetti

Besson³

et al. 2017

Front. Mar. Sci.

View full text Add to dashboard Cite

The MiniFluo-UV is a new glider-compatible optical sensor for measurements of dissolved organic matter (DOM) in natural waters. The working principle, sensor design and challenges faced during the validation phase are reported. The first in situ application of the sensor during three glider deployments in the NW Mediterranean sea (spring, summer, and fall) are also presented. For these campaigns, the two channels of the sensor were adjusted to target Tryptophan-like (excitation/emission wavelengths λ Ex /λ Em : 275/340 nm) and Phenanthrene-like (λ Ex /λ Em : 255/360 nm) fluorescence. These were chosen because they represent fluorophores of interest commonly found in seawater. While Tryptophan (an amino-acid believed to be a by-product of biological activity) is naturally found in the ocean, Phenanthrene (a polycyclic aromatic hydrocarbon) is mainly introduced in the environment by human activities. The addition of these variables to more common physical and biogeochemical glider measurements reveals new features of DOM dynamics in the Mediterranean Sea. For example, the temporal and spatial decoupling between Tryptophan-like and Chl-a fluorescence suggests that the former is not only a marker of phytoplankton activity, but could also give more subtle information on the microbial processes occurring. The identification of a Phenanthrene-like layer just below the pycnocline at all seasons also raises questions on the mechanisms driving its presence in the Mediterranean. Knowing that the role of ocean DOM on atmospheric carbon sequestration is becoming clearer, the high spatiotemporal resolution possible with this new sampling strategy may represents a key step toward our deep understanding of DOM dynamics and its role on the biological pump.

show abstract

Section: Confidence In Minifluo Measurementscontrasting

confidence: 44%

A New Glider-Compatible Optical Sensor for Dissolved Organic Matter Measurements: Test Case from the NW Mediterranean Sea

Cyr

Tedetti

Besson³

et al. 2017

Front. Mar. Sci.

View full text Add to dashboard Cite

show abstract

“…Alkaline hydrolysis for tryptophan determination was done according to the method of Wu and Tanoue 13 . Briefly, the fresh mushroom sample (1-3 g) was hydrolysed under nitrogen gas with 10 ml of 4 N NaOH and 200 µg of ascorbic acid as antioxidant in an autoclave at 110°C for 16 h and adjusted to pH 9.00.…”

Section: Total Amino Acid Analysismentioning

confidence: 99%

Untitled

Chirinang¹,

Intarapichet²

2009

ScienceAsia

View full text Add to dashboard Cite

ABSTRACT:The objective of this study was to investigate the amino acid composition and antioxidant properties of two oyster mushroom species, Pleurotus ostreatus and Pleurotus sajor-caju, commercially cultivated in NE Thailand. Proximate composition and dietary fibre of dried mushrooms were determined. Amino acid composition of fresh mushrooms was analysed by HPLC. Water and ethanol extracts were obtained from dried mushrooms and determined for total phenolic contents (TPC) by the Folin-Ciocalteu method, free radical scavenging efficacy by the DPPH method, and reducing power by the ferric reducing-antioxidant power method. Except for protein, proximate compositions of dried mushrooms were significantly different. Similar amino acid profiles in both mushrooms were obtained, with glutamic acid, aspartic acid, and arginine being the three most abundant. Water extracts contained higher TPC and possessed better antioxidant activities than did ethanol extracts for both mushrooms. Overall, P. ostreatus possessed more antioxidant than P. sajor-caju. The EC50 of P. ostreatus and P. sajor-caju water extracts were 11.56 and 13.38 mg/ml, respectively, while those of the ethanol extracts were 31.75 and 58.44 mg/ml, respectively.

show abstract

“…Lactose and ascorbic acid did not have tryptophan contamination when used as anti-oxidizing re-agents. Both improved tryptophan recovery, but ascorbic acid was more effective [52]. Therefore, determination of those compounds in the presence of each other is important.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Determination of Ascorbic Acid, Acetaminophen, and Tryptophan by Square Wave Voltammetry Using N‐(3,4‐Dihydroxyphenethyl)‐3,5‐Dinitrobenzamide‐Modified Carbon Nanotubes Paste Electrode

2012

View full text Add to dashboard Cite

N-(3,4-Dihydroxyphenethyl)-3,5-dinitrobenzamide modified-multiwall carbon nanotubes paste electrode was fabricated and used as an electrocatalyst for the oxidation of ascorbic acid (AA), acetaminophen (AC), and tryptophan (TP) at pH 7.0. In a mixture containing AA, AC, and TP, the separation potentials were large enough to determine those compounds individually and simultaneously. The peak currents obtained were found to be linearly dependent on AA, AC, and TP concentrations in the ranges of 0.03-70, 0.6-452, and 0.7-270 mmol L À1, respectively. The sensor was used for the determination of AC, AC, and TP in different real samples with satisfactory results.

show abstract

Sensitive Determination of Dissolved Tryptophan in Freshwater by Alkaline Hydrolysis and HPLC

Cited by 24 publications

References 20 publications

A New Glider-Compatible Optical Sensor for Dissolved Organic Matter Measurements: Test Case from the NW Mediterranean Sea

A New Glider-Compatible Optical Sensor for Dissolved Organic Matter Measurements: Test Case from the NW Mediterranean Sea

Untitled

Simultaneous Determination of Ascorbic Acid, Acetaminophen, and Tryptophan by Square Wave Voltammetry Using N‐(3,4‐Dihydroxyphenethyl)‐3,5‐Dinitrobenzamide‐Modified Carbon Nanotubes Paste Electrode

Contact Info

Product

Resources

About