scholarly journals A Simple Diffuse Reflectance Fourier Transform Infrared Spectroscopic Determination of Sulfur Dioxide in Ambient Air Using Potassium Tetrachloromercurate as the Absorbing Reagent

2007 ◽  
Vol 90 (4) ◽  
pp. 1180-1190
Author(s):  
Santosh Kumar Verma ◽  
Manas Kanti Deb ◽  
Samir Bajpai ◽  
Yukio Suzuki ◽  
Shekhar Kumar Sinha ◽  
...  

Abstract This paper presents development of a simple, rapid, and precise analytical method for determination of sulfur dioxide in ambient air by a gas to solid-phase conversion method. Sulfur dioxide is determined in the form of sulfite (SO32) because the absorbing reagent, potassium tetrachloromercurate (TCM), used in this method absorbs sulfur dioxide from the atmosphere in the form of sulfite. Determination of submicrogram levels of sulfur dioxide was based on the selection of a quantitative analytical peak at 495 cm1 among the 3 observed vibrational peaks for the dichlorosulfitomercurate complex formed after reaction of sulfur dioxide with TCM and measurement of absorbance using diffuse reflectance Fourier transform infrared spectroscopy. The limits of detection and quantification of the method were found to be 0.09 and 0.4 g/g SO32, respectively. The precision in terms of standard deviation and relative standard deviation (RSD) at a level of 2 g SO32/0.1 g KBr for n = 10 was found to be 0.036 g SO32 and 1.8%, respectively. The RSD (n = 10) for determination of sulfur dioxide in ambient air was observed to be in the range of 2.74.2%. The method proposed is time saving and eliminates the slow and cumbersome steps of pH maintenance of the reaction mixture and color formation of the U.S. Environmental Protection Agency recommended West and Gaeke spectrophotometric method and other methods for quantitative determination of sulfur dioxide.

2021 ◽  
Vol 30 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Ramsingh Kurrey ◽  
Kaushlya Thakur ◽  
Swati Chandrawanshi ◽  
Manas Kanti Deb

A new, simple, rapid and precise novel hyphenated diffuse reflectance-Fourier transform infrared spectroscopy (DRS-FTIR) technique for the simultaneous determination of the most frequently used cationic surfactants (CS+) i.e. cetyltrimethylammonium bromide (CTAB) and anionic surfactant (AS-) i.e. sodium dodecyl sulphate (SDS) in domestic, sewage and river wastewater samples has been stabilised. CS+ and AS- were analyzed using DRS-FTIR, the most steady and strongest vibrational IR peak at 2917.13 cm-1 for CTAB and 1226.07 for SDS were selected for the simultaneous quantiflcation of CS+ and AS- under the optimized condition such as effect of samples volume and effect of temperature. The limit of detection (LOD) and limit of quantiflcation (LOQ) of the present method were 5 µg/mL and 15 µg/mL, respectively. The absorbance and peak area were determined by the DRS-FTIR method, which shows excellent linearity with a correlation coefflcient value of 0.985 and 0.981 for the concentration range of 10-100 µg/mL. The standard deviation (SD) and relative standard deviation (RSD) for six replicate measurements were found to be 0.052 µg/L and 2.8 %, respectively.


2009 ◽  
Vol 63 (9) ◽  
pp. 1015-1021 ◽  
Author(s):  
David Pérez-Palacios ◽  
Sergio Armenta ◽  
Bernhard Lendl

A new flow-through Fourier transform infrared (FT-IR) sensor for oil in water analysis based on solid-phase spectroscopy on octadecyl (C18) silica particles has been developed. The C18 non-polar sorbent is placed inside the sensor and is able to retain hydrocarbons from water samples. The system does not require the use of chlorinated solvents, reducing the environmental impact, and the minimal sample handling stages serve to ensure sample integrity whilst reducing exposure of the analyst to any toxic hydrocarbons present within the samples. Fourier transform infrared (FT-IR) spectra were recorded by co-adding 32 scans at a resolution of 4 cm−1 and the band located at 1462 cm−1 due to the CH2 bending was integrated from 1475 to 1450 cm−1 using a baseline correction established between 1485 and 1440 cm−1 using the areas as analytical signal. The technique, which provides a limit of detection (LOD) of 22 mg L−1 and a precision expressed as relative standard deviation (RSD) lower than 5%, is considerably rapid and allows for a high level of automation.


2003 ◽  
Vol 86 (4) ◽  
pp. 685-693 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Cao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li ◽  
...  

Abstract Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100–0.687 mg/kg, the mean determination value range was 0.099–0.659 mg/kg; RSDR was 12.6–19.8%, RSDr was 3.1–8.5%; and HORRAT values were 0.7–1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.


2002 ◽  
Vol 85 (3) ◽  
pp. 654-664 ◽  
Author(s):  
Denis E LaCroix ◽  
Wayne R Wolf ◽  
G William Chase

Abstract This paper reports the results of the interlaboratory peer validation study of AOAC Peer-Verified Method (PVM) 1:2000 for the determination of niacin in infant formula by solid-phase extraction/liquid chromatography. We have used a Data Quality Objectives (DQO) approach to address not only method variability and robustness but also accuracy of data through the use of an appropriate reference material in conjunction with the interlaboratory validation study. Our DQO included the following: (1) statistical agreement of analytical results and quantitative recovery between 2 collaborating laboratories; (2) the repeatability relative standard deviation (RSDr) values and the HORRAT (Horwitz ratio) obtained (1.07), which satisfied the criteria of the Horwitz “limits of acceptability” at the analyte level present; (3) validation of lack of interference; and (4) accuracy agreement within assigned values for a certified reference material. National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1846 Infant Formula, with a certified value of 63.3 ± 7.6 μg/g for niacin content, was used as a test material for collaborative study and accuracy assessment. Niacin values obtained by the originating laboratory were 59.7 ± 4.0 μg/g (95% confidence interval [CI] = 1.4 μg/g with a relative standard deviation [RSD] of 6.7%) and by the peer laboratory were 56.6 ± 6.6 μg/g (95% CI = 4.1 μg/g, with an RSD of 11.7%). Statistical evaluation using the means equivalence test showed that nicotinic acid values obtained by the peer laboratory were equivalent to those values obtained by the originating laboratory. Linear calibration curves and quantitative recovery were obtained. Integration of the PVM process with a readily available certified reference material gives the user confidence in the accuracy of the data generated by the method through traceability to the reference material used.


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