Novel on-tap passive sampling for odorous compounds in drinking water

2008 ◽  
Vol 8 (2) ◽  
pp. 197-205
Author(s):  
Christophe Tondelier ◽  
David Benanou ◽  
Thomas Thouvenot ◽  
Arnaud Genin
Keyword(s):  
Drinking Water ◽  
Passive Sampling ◽  
Water Flow Rate ◽  
Internal Standard ◽  
High Sensitivity ◽  
Qualitative Aspect ◽  
Mixing Chamber ◽  
In Series ◽  
Loading And Unloading ◽  
Private Network

Because taste and odour events in drinking water are often fleeting and unpredictable phenomena, an innovating passive sampler has been developed to trap off-flavour compounds, directly at the tap of the consumer: ARISTOT (Advanced Relevant Investigation Sampler for Taste & Odour at Tap). Each tool is equipped with seven SBSE stir bars, magnetic stirring roads coated with a polydimethylsiloxane (PDMS) phase, allowing the sorption of water organic compounds into PDMS at each tap opening. To study the efficiency of these passives samplers, a private network pilot unit has been created in our laboratory, equipped with four faucets in series, solenoids valves for automation of the system and a mixing chamber, developed to spike drinking water with odourous compounds in order to have homogenous smelling water at each tap. After enrichment, the bars are taken out and are then in-line thermo-desorbed and analysed by gas chromatography coupled with a mass spectrometer. Results showed a high sensitivity of the system, which was able to quickly analyse odourous compounds at the sub ng/L level. A “multishot” method was developed to analyse every molecule trapped on the seven stir bars in only one chromatographic run increasing sensitivity. To follow enrichment of stir bars, loading and unloading were studied and showed a very slight unloading of the stir bar under a clean water flow rate which allowed us to previously spike every stir bar with an internal standard to see analytical variations. The influence of heated water was also investigated and seems to lead to a higher unloading of the stir bar, but according to a qualitative aspect this loss is balanced by the high sensitivity.

scholarly journals Linking a rapid throughput plate-assay with high-sensitivity stable-isotope label LCMS quantification permits the identification and characterisation of low β-L-ODAP grass pea lines

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Peter M. F. Emmrich ◽  
Martin Rejzek ◽  
Lionel Hill ◽  
Paul Brett ◽  
Anne Edwards ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Internal Standard ◽  
High Sensitivity ◽  
Spectrophotometric Assay ◽  
Rapid Screening ◽  
Grass Pea ◽  
Stable Isotope Label ◽  
Tissue Samples ◽  
Plate Assay ◽  
Accurate Quantification

Abstract Background Grass pea (Lathyrus sativus) is an underutilised crop with high tolerance to drought and flooding stress and potential for maintaining food and nutritional security in the face of climate change. The presence of the neurotoxin β-L-oxalyl-2,3-diaminopropionic acid (β-L-ODAP) in tissues of the plant has limited its adoption as a staple crop. To assist in the detection of material with very low neurotoxin toxin levels, we have developed two novel methods to assay ODAP. The first, a version of a widely used spectrophotometric assay, modified for increased throughput, permits rapid screening of large populations of germplasm for low toxin lines and the second is a novel, mass spectrometric procedure to detect very small quantities of ODAP for research purposes and characterisation of new varieties. Results A plate assay, based on an established spectrophotometric method enabling high-throughput ODAP measurements, is described. In addition, we describe a novel liquid chromatography mass spectrometry (LCMS)-based method for β-L-ODAP-quantification. This method utilises an internal standard (di-13C-labelled β-L-ODAP) allowing accurate quantification of β-L-ODAP in grass pea tissue samples. The synthesis of this standard is also described. The two methods are compared; the spectrophotometric assay lacked sensitivity and detected ODAP-like absorbance in chickpea and pea whereas the LCMS method did not detect any β-L-ODAP in these species. The LCMS method was also used to quantify β-L-ODAP accurately in different tissues of grass pea. Conclusions The plate-based spectrophotometric assay allows quantification of total ODAP in large numbers of samples, but its low sensitivity and inability to differentiate α- and β-L-ODAP limit its usefulness for accurate quantification in low-ODAP samples. Coupled to the use of a stable isotope internal standard with LCMS that allows accurate quantification of β-L-ODAP in grass pea samples with high sensitivity, these methods permit the identification and characterisation of grass pea lines with a very low ODAP content. The LCMS method is offered as a new ‘gold standard’ for β-L-ODAP quantification, especially for the validation of existing and novel low- and/or zero-β-L-ODAP genotypes.

Rapid detection and enumeration of total bacteria in drinking water and tea beverages using a laboratory-built high-sensitivity flow cytometer

2015 ◽  
Vol 7 (7) ◽  
pp. 3072-3079 ◽  
Author(s):  
Muxin Yu ◽  
Lina Wu ◽  
Tianxun Huang ◽  
Shuo Wang ◽  
Xiaomei Yan
Keyword(s):  
Drinking Water ◽  
Rapid Detection ◽  
High Sensitivity ◽  
Flow Cytometer ◽  
Total Bacteria

This paper describes a method for the rapid detection and enumeration of total bacteria in drinking water and tea beverages.

The Study on Organic Acid Detection Using Lon Chromatography

2012 ◽  
Vol 424-425 ◽  
pp. 923-926
Author(s):  
Xiao Jian Hu ◽  
Wen Chen ◽  
Li Li ◽  
Jin Ping Zhou ◽  
Bao Shou Guo ◽  
...  
Keyword(s):  
Drinking Water ◽  
Convenient Method ◽  
High Sensitivity ◽  
Microwave Oven ◽  
Good Recovery ◽  
Microwave Technology ◽  
Trace Level ◽  
Recovery Treatment ◽  
Technology Foundation

A simple and convenient method for the determination of μ g/l level in the real drinking water bromate overcome traditional methods of defects. Argentina by electrolyzing the smallest electrode interference and then focus on extra chlorine use microwave technology foundation evaporation and concentration, the proposed method is very sensitive to the determination of trace level of the sales of the drinking water. And a microwave oven, drinking water ten times the sample can be concentrated in 10 minutes can get and good recovery. Treatment of the silver electrode, the method of interference, and can effectively eliminate the Cl- This method is successfully applied to the detection in water sample level in the trace. It is the advantage of the operation is simple, fast, high sensitivity, accurate results. This method can be applied widely, suitable for trace analysis of water samples.

An improved method for determining microbially available phosphorus in drinking water

2016 ◽  
Vol 16 (4) ◽  
pp. 1149-1158 ◽  
Author(s):  
Gang Wen ◽  
Qin Deng ◽  
Ting-Lin Huang ◽  
Jun Ma
Keyword(s):  
Drinking Water ◽  
Microbial Consortium ◽  
Incubation Temperature ◽  
Organic Phosphorus ◽  
High Sensitivity ◽  
Cell Number ◽  
Growth Potential ◽  
Utilization Efficiency ◽  
Available Phosphorus ◽  
Time Saving

Microbially available phosphorus (MAP) is the labile phosphorus that is readily assimilated by microorganisms, which is linearly correlated to bacterial re-growth in drinking water in some regions. The conventional MAP bioassay for drinking water was originally developed by Markku based on the growth potential of Pseudomonas fluorescens P17 (P17). However, the bioassay bears some demerits, such as time-consuming and labor-intensive enumeration. For convenience, an alternative method based on a similar principle was developed to assess the content of MAP in drinking water, in which natural microbial consortium was used as inoculum instead of pure culture P17, cell number was counted using flow cytometry (FCM), and cultivation at 30 °C was adopted. Natural microbial consortium is able to efficiently utilize organic phosphorus and exhibit high sensitivity since more cells are produced per μg P utilized. FCM is a rapid method to count all bacteria growing in drinking water. With incubation temperature increasing up to 30 °C, there is a shorter test period (64 h), excellent sensitivity and better utilization efficiency for organic phosphorus. The results show that the developed bioassay is sensitive, time-saving and easily operated.

scholarly journals Design of an underwater acoustic array for full ocean depth multi-beam echo sounder

2019 ◽  
Vol 283 ◽  
pp. 05002
Author(s):  
Haoqi Hao ◽  
Tiejian Xia ◽  
Min Xie
Keyword(s):  
High Reliability ◽  
Integrated Design ◽  
High Sensitivity ◽  
Underwater Acoustic ◽  
Technical Requirements ◽  
Planar Array ◽  
In Series ◽  
Stable Performance ◽  
Acoustic Array ◽  
Echo Sounder

In order to meet the technical requirements of full ocean depth multibeam echo sounder, the underwater acoustic array must have the ability of wide coverage, broadband response, high sensitivity and high reliability. This paper presents a design of underwater acoustic array based on Mills cross configuration with separate transmitting and receiving units. The arrays have modules design, hence the beamwidth of the array can be adjusted according to particular installation requirements. The working frequency band of the arrays is between 10.5kHz to 13.5kHz, and the coverage angle can cover -71.6°~71.6°. The Integrated design is used to achieve a wide-angle beam coverage of the planar array, which combines the transducer and the sound baffle together to realize a wide directivity of the array elements. The longitudinal bending transducers are designed to meet the broadband requirements for the transmitting array, which are Tonpilz transducers with flexural radiating head. On the other hand, each element of the receiving array is composed of several hydrophones, which are connected in series to achieve high sensitivity. The double-layer watertight technology is also applied in our design, ensuring stable performance and long service life.

Simultaneous determination of endogenous retinoic acid isomers and retinol in human plasma by isocratic normal-phase HPLC with ultraviolet detection

1994 ◽  
Vol 40 (1) ◽  
pp. 48-51 ◽  
Author(s):  
E Meyer ◽  
W E Lambert ◽  
A P De Leenheer
Keyword(s):  
Retinoic Acid ◽  
Human Plasma ◽  
Simple Procedure ◽  
Internal Standard ◽  
High Sensitivity ◽  
Normal Phase ◽  
Ultraviolet Detection ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Normal Phase Hplc

Abstract We describe a rapid and simple procedure for the simultaneous quantitation of endogenous 13-cis-retinoic acid, all-trans-retinoic acid, and retinol by isocratic normal-phase HPLC with ultraviolet detection, in 0.5 mL of human plasma. A silica adsorption column was eluted with n-hexane:2-propanol:acetic acid (200:0.7:0.135 by vol) at 0.9 mL/min, and the effluent monitored at 350 nm. The arotinoid ethylsulfonic acid Ro 15-1570 was used as the internal standard. High sensitivity, allowing quantitation of physiological concentrations, was achieved, particularly for the retinoic acid isomers. The detection limits were 0.5 microgram/L in plasma for both 13-cis- and trans-retinoic acid, and 10 micrograms/L for retinol. The CVs for between-day determinations of the lowest quality-control concentration (n = 12) were 4.8% for 13-cis-retinoic acid, 3.4% for trans-retinoic acid, and 3.0% for retinol. The mean (+/- SD) concentrations of 13-cis-retinoic acid (1.79 +/- 0.56 microgram/L), trans-retinoic acid (1.35 +/- 0.42 microgram/L), and retinol (533 +/- 58 micrograms/L) measured in plasma from 22 healthy volunteers agreed well with those previously reported.

High Pressure Liquid Chromatography of Zearalenone and Zearalenols in Rat Urine and Liver

1982 ◽  
Vol 65 (1) ◽  
pp. 8-13
Author(s):  
Lynda J James ◽  
Larry G McGirr ◽  
Trevor K Smith
Keyword(s):  
High Pressure ◽  
Methylene Chloride ◽  
Internal Standard ◽  
Free Form ◽  
Chromatographic Technique ◽  
Rat Urine ◽  
Glucuronide Conjugation ◽  
In Series ◽  
Internal Standardization ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic technique with internal standardization has been developed for determining zearalenone and metabolites in rat urine and liver. Following extraction with methylene chloride and solvent partition, samples are cleaned up by applying the extract to a Sephadex LH-20 column and eluting with a mixture of benzene-methanol (85 + 15). Compounds were resolved on 2 Partisil- 10 columns (25 cm × 4.6 mm id) in series with a mobile phase of isooctane-chloroform-methanol (35 + 25 + 3), and detected at 280 nm. The internal standard was 6'αa-acetoxyzearalane. Limits of detection were about 2.0 ng for zearalenone and 5.0 ng for zearalenols (6'-hydroxyzearalane). Zearalenone and zearalenols were excreted mainly in free form with relatively little glucuronide conjugation. Metabolism of zearalenone to free zearalenol was minor compared with formation of bound forms.

The Research on Mineralization of Desalinated Water by Dissolving Ore for Entering into Municipal Water Supply Network

2013 ◽  
Vol 790 ◽  
pp. 463-466
Author(s):  
Na Tang ◽  
Wei Wang ◽  
Lei Zhang ◽  
Peng Gao Cheng ◽  
Jian Qian Gong ◽  
...  
Keyword(s):  
Particle Size ◽  
Drinking Water ◽  
Calcium Ions ◽  
Water Flow Rate ◽  
Packed Bed ◽  
Pipe Network ◽  
Main Method ◽  
Municipal Water Supply ◽  
Desalinated Water ◽  
Bed Height

Desalination is the main method to solve the lack of freshwater resources in coastal areas. However, the desalinated water needs further treatment to have good chemical stability and meet the drinking water health standards before transporting by municipal pipe network. Considering desalinated seawater in Beijiang Power Plant and current situation of municipal pipe network, the desalinated water was mineralized by dissolving limestone with CO2 in this work. The process results in an enrichment of the water with calcium ions and carbonate. The effect of the limestone particle size, pH, the packed bed height and desalinated water flow rate on result water was investigated, which could offer a principle for the utilization of desalinated.

Gas Chromatographic Determination of Total Active Ingredient Content of Karathane Technical and Karathane WD. I. Development of the Method

1970 ◽  
Vol 53 (5) ◽  
pp. 887-895
Author(s):  
C P Kurtz ◽  
H Baum ◽  
C Swithenbank
Keyword(s):  
Active Ingredient ◽  
Silicone Oil ◽  
Internal Standard ◽  
Direct Determination ◽  
Chromatographic Determination ◽  
Working Standard ◽  
Column Temperature ◽  
Glass Column ◽  
In Series

Abstract A new GLC method for the direct determination of the active ingredient in Karathane Technical and Karathane WD is presented. The internal standard (4,6-dinitro-o-cresol) in nitrobenzene solution is added to the sample, or the extract residue in the case of Karathane WD, and the solution is chromatographed on a flame ionization instrument, using an 8’ glass column packed with 3% QF-1 silicone oil on 60–80 mesh Gas Chrom Q. Column temperature is programmed from 100 to 230°C. A working standard of known composition is run in the same manner in series with the sample. The precision of a single determination of the total 2,4- and 2,6-dinitrooctylphenyl crotonate isomers (about 74%) in Karathane Technical and the total dinitrooctylphenols and mononitrooctylphenols (about 6%) is s = 0.5% absolute. Data on the analysis of a limited number of Karathane WD samples show good agreement for the total active ingredient.

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