scholarly journals Spectrofluorimetric Determination of Formaldehyde in Maple Syrup

2002 ◽  
Vol 85 (5) ◽  
pp. 1144-1147 ◽  
Author(s):  
Luc Lagace ◽  
Johanne Dumont ◽  
Germain Brazeau ◽  
Andree Soucy ◽  
Jonathan Haché ◽  
...  
Keyword(s):  
Standard Method ◽  
Simple Method ◽  
Limits Of Detection ◽  
Maple Syrup ◽  
Spectrofluorimetric Determination

Abstract A quick and simple method was developed for determination of formaldehyde in maple syrup. In this method, formaldehyde reacts with Fluoral P to form a complex which is chemically extracted by isobutanol and determined by spectrofluorimetry. Performance, as gauged by the limits of detection (0.16 mg/kg) and quantitation (0.21 mg/kg), recovery (>79%), and variability (1.9–16.1%, depending on fortification level and class of syrup) were superior to the current official AOAC standard method.

Determination of Pesticides in Indoor Air and Dust

1993 ◽  
Vol 76 (5) ◽  
pp. 1121-1126 ◽  
Author(s):  
Kurt S Roinestad ◽  
Judith B Louis ◽  
Joseph D Rosen
Keyword(s):  
Indoor Air ◽  
Pesticide Exposure ◽  
Ion Trap ◽  
Gas Chromatography Mass Spectrometry ◽  
Simple Method ◽  
Limits Of Detection ◽  
Ion Trap Mass Spectrometer ◽  
Household Chemicals ◽  
Multiresidue Determination

Abstract Improved analytical and sampling methods were developed for the multiresidue determination of pesticides in indoor air. Air analysis consists of adsorption of the pesticides in 1 m3 of air onto Tenax TA via an air sampling pump, desorption with acetone, and determination and quantitation by gas chromatography/mass spectrometry (GC/MS) with chemical ionization on an ion trap mass spectrometer. Limits of detection for the 23 pesticides studied ranged from 0.5 ng/m3 for chlorpyrifos and diazinon to 30 ng/m3 for o-phenylphenol (approximately 0.5-30 parts per trillion on a w/w basis). A simple method for the detection of pesticides in dust was also developed. This method involves emptying the contents of a vacuum cleaner bag into a standard household food processor and extracting 1 g homogenized dust with acetone before GC/MS. Limits of detection were 25-100 ppb because of interferences by common household chemicals. However, pesticide concentrations were higher in dust than in air, therefore, analysis of dust is a better indicator of indoor pesticide exposure.

Problems in extraction and spectrophotometric determination of chlorophyll from epilithic microbial biofilms: towards a standard method

1999 ◽  
Vol 79 (3) ◽  
pp. 551-558 ◽  
Author(s):  
R.C. Thompson ◽  
M.L. Tobin ◽  
S.J. Hawkins ◽  
T.A. Norton
Keyword(s):  
Standard Method ◽  
Relative Efficiency ◽  
Room Temperature ◽  
Standard Procedure ◽  
Suspended Material ◽  
Sample Collection ◽  
Simple Method ◽  
Microbial Biofilms ◽  
Epilithic Biofilms

A variety of methods are available to extract chlorophyll from epilithic biofilms using solvents. The relative efficiency of these has not been determined simultaneously and there is no recognized standard procedure. In this paper techniques for sample collection, storage, preparation and extraction are reviewed and compared experimentally.Extraction of chlorophyll was incomplete unless biofilms were fully hydrated. This factor was highly significant for all the solvents tested, with at least three times more pigment being extracted from hydrated samples than from dry ones. Methanol was the most efficient solvent, releasing over 96% of the total chlorophyll during a single extraction; hot ethanol extracted 86%, while acetone extracted less than 50%. Sonicating samples during extraction did not release any additional pigment. Centrifuging to remove suspended material did not alter estimates and was not advantageous. Rugose rock surfaces released more chlorophyll than smooth ones. However, a simple method to quantify surface rugosity at an appropriate scale was not available.Based on these observations, a standard method for chlorophyll extractions from epilithic biofilms using 100% methanol at room temperature (20°C) is proposed. This technique requires considerably less supervision than previously preferred methods and gave a chlorophyll extract which was stable for 15 h.

Synchronous Spectrofluorimetric Determination of Total Amounts of the Six Polycyclic Aromatic Hydrocarbons Officially Designated as Indicators of Drinking Water Quality

1995 ◽  
Vol 78 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Maria J López De Alda-Villaizan ◽  
Soma García-Falcon ◽  
Maria A Lage-Yusty ◽  
Jesús Simal-Lozano
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Surface Waters ◽  
Aromatic Hydrocarbons ◽  
Simple Method ◽  
Quantitation Limit ◽  
Spectrofluorimetric Determination ◽  
Polycyclic Aromatic

Abstract We report a quick, simple method for determination of the joint concentration of the 6 polycyclic aromatic hydrocarbons (PAHs) designated by current legislation as quality indicators for drinking water and for surface waters destined for use as drinking water. Water samples are extracted with hexane, and total indicator PAH concentration is determined by synchronous spectrofluorimetry (optimal instrumental parameters are reported). The detection limit (5.0 ng/L), quantitation limit (8.4 ng/L), precision (coefficient of variation, 3.8%), and accuracy (recovery, 77%) were well within the legal bounds for reference methods.

Development of a simple method for the determination of single nucleotide polymorphisms

2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Simple Method ◽  
Single Nucleotide

Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi
Keyword(s):  
Standard Method ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Oxidizing Agent ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Cerium Ion ◽  
Blank Solution

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.

A Standard Primary Toxicity Bioassay Using Daphnia Magna as a Test Species

1977 ◽  
Vol 12 (1) ◽  
pp. 27-50 ◽  
Author(s):  
L.A. Behie ◽  
J.E. Zajic ◽  
D. Berk ◽  
R.J.P. Brouzes ◽  
V.A. Naish
Keyword(s):  
Statistical Analysis ◽  
Daphnia Magna ◽  
Biological Indicator ◽  
Pulp And Paper ◽  
Toxicity Bioassay ◽  
Simple Method ◽  
Test Species ◽  
Test Organisms ◽  
Dilution Water

Abstract Although Daphnia magna have been widely used in the determination of the toxicity of various substances, there are no reports in the literature that describe a rigorous bioassay method using this organism as a test species. The test described herein involves the standariza-tion of various important aspects of the method such as the age of the test organisms, and the dilution water used for the preparation of the various toxicant concentrations. Also described is a simple method for the statistical analysis of the results. The sensitivity of the proposed bioassay is demonstrated by determining the toxicity of various pulp and paper effluents. Finally, extensive bioassays were carried out simultaneously with rainbow trout and Daphnia magna indicating that Daphnia are as good a biological indicator of acute toxicity as fish.

Determination of alcohols in mixtures by 19F NMR spectroscopy using hexefluoroacetone reagent

1982 ◽  
Vol 47 (7) ◽  
pp. 1973-1978 ◽  
Author(s):  
Jiří Karhan ◽  
Zbyněk Ksandr ◽  
Jiřina Vlková ◽  
Věra Špatná
Keyword(s):  
Standard Deviation ◽  
Nmr Spectroscopy ◽  
Standard Method ◽  
Internal Standard ◽  
Internal Standard Method ◽  
Concentration Region ◽  
Experimental Conditions ◽  
Curve Method ◽  
Sample Preparation Procedure

The determination of alcohols by 19F NMR spectroscopy making use of their reaction with hexafluoroacetone giving rise to hemiacetals was studied on butanols. The calibration curve method and the internal standard method were used and the results were mutually compared. The effects of some experimental conditions, viz. the sample preparation procedure, concentration, spectrometer setting, and electronic integration, were investigated; the conditions, particularly the concentrations, proved to have a statistically significant effect on the results of determination. For the internal standard method, the standard deviation was 0.061 in the concentration region 0.032-0.74 mol l-1. The method was applied to a determination of alcohols in the distillation residue from an oxo synthesis.

Sign in / Sign up

Export Citation Format

Share Document