sadia sherazi - Academia.edu (original) (raw)
Papers by sadia sherazi
Arabian Journal of Chemistry, 2014
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Analytical Methods, 2014
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Vibrational Spectroscopy, 2011
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Vibrational Spectroscopy, 2011
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Talanta, 2009
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Talanta, 2010
The aim of present study was to develop a simple method on UV spectrometer for the determination ... more The aim of present study was to develop a simple method on UV spectrometer for the determination of peroxide value (PV) of the frying oil. The basis of the PV determination was the stoichiometric reaction of triphenylphosphine (TPP) with the hydroperoxides present in frying oil to produce triphenylphosphine oxide (TPPO), which exhibits a readily measurable absorption band at 240 nm by ultraviolet region. The PV ranged between 0.15 and 11.66 meq. of active oxygen per kilogram of oil as the canola oil was heated from 0 to 12h in the fryer at 180 degrees C. The proposed method was correlated with official AOCS titration method and best correlation coefficient (R(2)=0.99525) was achieved, proving that there is no significant difference in the results. Therefore, developed method could serve as an alternative to the titration method, for the determination of PV in frying oils.
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Talanta, 2008
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Meat Science, 2008
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Food Chemistry, 2008
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Food Chemistry, 2009
The amount of trans fatty acids (TFA) in fourteen industrially hydrogenated and deodorized oils w... more The amount of trans fatty acids (TFA) in fourteen industrially hydrogenated and deodorized oils was determined. To achieve better sensitivity 200μm KCl cell was used in transmission Fourier transform infrared (FT-IR) spectroscopy. The results of transmission FT-IR spectroscopy were evaluated by gas chromatography (GC) with flame ionization detector (FID), and found to be comparable. All analyzed cooking oil samples had
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Food Chemistry, 2013
Melamine is a nitrogenous chemical substance used principally as a starting material for the manu... more Melamine is a nitrogenous chemical substance used principally as a starting material for the manufacture of synthetic resins. Due to its very high proportion of nitrogen melamine has been added illegitimately to foods and feeds to increase the measured protein content, which determines the value of the product. These issues prompted private as well as governmental laboratories to develop methods for the analysis of melamine in a wide variety of food products and ingredients. Owing to this fact present study is aimed to use single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared spectroscopy (FTIR) method as an effective rapid tool for the detection and quantification of melamine in milk (liquid and powder). Partial least-squares (PLS) models were established for correlating spectral data to melamine concentration with R(2)>0.99, and RMSEC 0.370. Linear calibration curves were obtained over the calibration range of 25-0.0625%. The LOD and LOQ of the method was 0.00025% (2.5 ppm) and 0.0015% (15 ppm) respectively. Proposed SB-ATR-FTIR method requires little or no sample preparation with an assay time of 1-2 min.
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Food Additives & Contaminants: Part B, 2014
Two hundred and fifteen broiler poultry feed samples were analysed over the time period of one ye... more Two hundred and fifteen broiler poultry feed samples were analysed over the time period of one year for the co-occurrence of aflatoxins and deoxynivalenol (DON). These were determined by GC-MS and ELISA, respectively. LOD values for aflatoxins and DON were 0.5 and 5 µg/kg, respectively. From all investigated 215 poultry feed samples, aflatoxins and DON co-occurred in 100 samples (46%). DON was detected in 114 samples while 100 samples also were positive for aflatoxins. Mean concentrations of positive samples for aflatoxins and DON were 18 and 807 µg/kg, respectively. Twenty-one DON-positive and 42 aflatoxin positive samples were contaminated above the EU maximum legal limits of 1000 µg/kg and 20 µg/kg, respectively. The present study provided useful data on aflatoxin and DON contamination, which may be helpful for future strategies to control contamination and to formulate standards in poultry feeds.
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Chromatographia, 2014
ABSTRACT Three different gas chromatographic detection techniques were applied for the determinat... more ABSTRACT Three different gas chromatographic detection techniques were applied for the determination of deoxynivalenol (DON) present in poultry feed samples. Extraction and cleanup procedures were kept the same for GC–FID, GC–ECD and GC–MS methods. Although all three GC methods provided good and comparable results, but more attention was focused on GC–FID due to its lower cost and easy availability in many laboratories. Therefore, a short 15 m DB-1 short column was introduced for the determination of DON in poultry feed to reduce the time of analysis and initial cost of column. An inter-laboratory study for GC–FID was performed in two laboratories using four naturally DONS-contaminated feed samples and one spiked with standard. The relative standard deviations for repeatability (RSDr) and relative standard deviations for reproducibility (RSDR) of naturally contaminated feed were in the range 5–23 and 11–24 %, respectively. The Horwitz Ratio (HORRAT) was less than 1.0 in each sample. From the spiking test, recovery, RSDr, RSDR and value of HORRAT were 93, 5, 11 and 0.6 %, respectively. For GC–FID method, limit of quantification was found to be 6 μg kg−1. Thus, GC–FID method using 15 m DB-1 capillary column is sensitive and validated analytical method for the determination of DON for poultry feed.
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Arabian Journal of Chemistry, 2014
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Analytical Methods, 2014
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Vibrational Spectroscopy, 2011
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Vibrational Spectroscopy, 2011
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Talanta, 2009
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Talanta, 2010
The aim of present study was to develop a simple method on UV spectrometer for the determination ... more The aim of present study was to develop a simple method on UV spectrometer for the determination of peroxide value (PV) of the frying oil. The basis of the PV determination was the stoichiometric reaction of triphenylphosphine (TPP) with the hydroperoxides present in frying oil to produce triphenylphosphine oxide (TPPO), which exhibits a readily measurable absorption band at 240 nm by ultraviolet region. The PV ranged between 0.15 and 11.66 meq. of active oxygen per kilogram of oil as the canola oil was heated from 0 to 12h in the fryer at 180 degrees C. The proposed method was correlated with official AOCS titration method and best correlation coefficient (R(2)=0.99525) was achieved, proving that there is no significant difference in the results. Therefore, developed method could serve as an alternative to the titration method, for the determination of PV in frying oils.
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Talanta, 2008
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Meat Science, 2008
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Food Chemistry, 2008
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Food Chemistry, 2009
The amount of trans fatty acids (TFA) in fourteen industrially hydrogenated and deodorized oils w... more The amount of trans fatty acids (TFA) in fourteen industrially hydrogenated and deodorized oils was determined. To achieve better sensitivity 200μm KCl cell was used in transmission Fourier transform infrared (FT-IR) spectroscopy. The results of transmission FT-IR spectroscopy were evaluated by gas chromatography (GC) with flame ionization detector (FID), and found to be comparable. All analyzed cooking oil samples had
Bookmarks Related papers MentionsView impact
Food Chemistry, 2013
Melamine is a nitrogenous chemical substance used principally as a starting material for the manu... more Melamine is a nitrogenous chemical substance used principally as a starting material for the manufacture of synthetic resins. Due to its very high proportion of nitrogen melamine has been added illegitimately to foods and feeds to increase the measured protein content, which determines the value of the product. These issues prompted private as well as governmental laboratories to develop methods for the analysis of melamine in a wide variety of food products and ingredients. Owing to this fact present study is aimed to use single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared spectroscopy (FTIR) method as an effective rapid tool for the detection and quantification of melamine in milk (liquid and powder). Partial least-squares (PLS) models were established for correlating spectral data to melamine concentration with R(2)>0.99, and RMSEC 0.370. Linear calibration curves were obtained over the calibration range of 25-0.0625%. The LOD and LOQ of the method was 0.00025% (2.5 ppm) and 0.0015% (15 ppm) respectively. Proposed SB-ATR-FTIR method requires little or no sample preparation with an assay time of 1-2 min.
Bookmarks Related papers MentionsView impact
Food Additives & Contaminants: Part B, 2014
Two hundred and fifteen broiler poultry feed samples were analysed over the time period of one ye... more Two hundred and fifteen broiler poultry feed samples were analysed over the time period of one year for the co-occurrence of aflatoxins and deoxynivalenol (DON). These were determined by GC-MS and ELISA, respectively. LOD values for aflatoxins and DON were 0.5 and 5 µg/kg, respectively. From all investigated 215 poultry feed samples, aflatoxins and DON co-occurred in 100 samples (46%). DON was detected in 114 samples while 100 samples also were positive for aflatoxins. Mean concentrations of positive samples for aflatoxins and DON were 18 and 807 µg/kg, respectively. Twenty-one DON-positive and 42 aflatoxin positive samples were contaminated above the EU maximum legal limits of 1000 µg/kg and 20 µg/kg, respectively. The present study provided useful data on aflatoxin and DON contamination, which may be helpful for future strategies to control contamination and to formulate standards in poultry feeds.
Bookmarks Related papers MentionsView impact
Chromatographia, 2014
ABSTRACT Three different gas chromatographic detection techniques were applied for the determinat... more ABSTRACT Three different gas chromatographic detection techniques were applied for the determination of deoxynivalenol (DON) present in poultry feed samples. Extraction and cleanup procedures were kept the same for GC–FID, GC–ECD and GC–MS methods. Although all three GC methods provided good and comparable results, but more attention was focused on GC–FID due to its lower cost and easy availability in many laboratories. Therefore, a short 15 m DB-1 short column was introduced for the determination of DON in poultry feed to reduce the time of analysis and initial cost of column. An inter-laboratory study for GC–FID was performed in two laboratories using four naturally DONS-contaminated feed samples and one spiked with standard. The relative standard deviations for repeatability (RSDr) and relative standard deviations for reproducibility (RSDR) of naturally contaminated feed were in the range 5–23 and 11–24 %, respectively. The Horwitz Ratio (HORRAT) was less than 1.0 in each sample. From the spiking test, recovery, RSDr, RSDR and value of HORRAT were 93, 5, 11 and 0.6 %, respectively. For GC–FID method, limit of quantification was found to be 6 μg kg−1. Thus, GC–FID method using 15 m DB-1 capillary column is sensitive and validated analytical method for the determination of DON for poultry feed.
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