Method for Residues Analysis of Isoxaflutole and Its Metabolites in Maize
Mao Jia,
Feng Yizhi,
Qi Xiaoxue,
Han Jifeng,
Pan Jinju,
Liang Lin,
Liu Wei,
Zuo Bojun
Issue:
Volume 7, Issue 4, August 2019
Pages:
72-76
Received:
11 September 2019
Accepted:
7 October 2019
Published:
17 October 2019
Abstract: A rapid and sensitive analytical method for the determination of isoxaflutole and diketonitrile (DKN) residues in maize was established based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The samples were extracted with acetonitrile and purified with octadecylsilane (C18). The mass spectrometer was performed in multi-reaction monitoring mode, and electrospray ionization in negative mode was selected. The isoxaflutole and DKN residues were quantified by the external standard method using the matched standard solution to compensate for matrix effect. The results indicated that the calibration curves of isoxaflutole and DKN were linear in the range of 0.005-0.5mg/L with correlation coefficients of more than 0.9922. When the addition level ranged from 0.01 to 0.1mg/kg the average recoveries of isoxaflutole and DKN in maize, green maize and straw were 95%-108%, and the relative standard deviation (RSD) ranged from 2% to 11%. The limit of quantitation (LOQ) were 0.01 mg/kg in different matrices. This method has many characteristics, such as simple, rapid and accurate, and can be adapted for the confirmation of isoxaflutole and DKN residues in maize samples.
Abstract: A rapid and sensitive analytical method for the determination of isoxaflutole and diketonitrile (DKN) residues in maize was established based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The samples were extracted with acetonitrile and purified wi...
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2-oxo-2H-chromen-3-yl Propionate and 2-oxo-2H-chromen-3-yl Acetate: Short-step Synthesis, Characterization and Fluorescence Properties
Jules Yoda,
Salfo Ouédraogo,
Adama Saba
Issue:
Volume 7, Issue 4, August 2019
Pages:
77-81
Received:
20 September 2019
Accepted:
14 October 2019
Published:
23 October 2019
Abstract: Natural or synthetic coumarins are of great interest, since many of them show prominent biological activity and photochemical characteristics. In particular, hydroxycoumarins and their derivatives have been extensively studied in various fields such as biology, medicine, physics and chemistry. Among the well-known compounds is 7-hydroxycoumarin, also known as umbelliferone and 4-hydroxycoumarin. Against 3-hydroxycoumarin and its derivatives are less known and studied. In this study, new acyl derivatives were synthesized from 3-hydroxycoumarin or chromen-2,3-dione its tautomeric form and chloride acid in the presence of an appropriated base. The structures of the newly obtained compounds were confirmed by elemental analysis, mass spectrometry (MS), IR and NMR spectrometry and X-ray diffractometry. In addition, the fluorescence properties of the titre compounds were also studied in both liquid and solid state. In liquid media, the study concerned their behaviour in fluorescence emission spectrometry in 6 solvents of different polarities. The new heterocyclic compounds have been successfully synthesized. Fluorescence spectrum analyses show that these compounds are all fluorescent in both solid and liquid state with varying fluorescence intensities (IF). On solvatochromic analyses, it appears that the behaviour of the spectrum depends strongly on the solvent. The fluorescence intensity and wavelength (λem) vary depending on the nature of the substituent (R) and especially that of the solvent. It should also be noted that chloroform is the solvent that most enhances the fluorescence of the compounds.
Abstract: Natural or synthetic coumarins are of great interest, since many of them show prominent biological activity and photochemical characteristics. In particular, hydroxycoumarins and their derivatives have been extensively studied in various fields such as biology, medicine, physics and chemistry. Among the well-known compounds is 7-hydroxycoumarin, al...
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A Comparative Study of Water Quality Between Hot Spring and Borehole Waters of Mara, Shinyanga and Manyara Regions of Tanzania
Samwel Alfred Maseke,
Maheswara Rao Vegi
Issue:
Volume 7, Issue 4, August 2019
Pages:
82-89
Received:
25 September 2019
Accepted:
11 October 2019
Published:
23 October 2019
Abstract: This study conducted for the comparison of physico-chemical parameters between hot springs and borehole waters. Fourteen samples were collected at Mara, Shinyanga and Manyara in Tanzania. Multimeter used for the analysis of physical parameters pH, EC, TDS, salinity and turbidity. Titrimetric methods were used for the determination of Cl-, total hardness, Ca2+ and Mg2+. UV-Vis. Spectrophotometric method for NO3-, SO42-, F-, Fe2+ and Mn2+ and Flame Atomic Absorption Spectrometer for Cd2+, Zn2+, Ni2+, Cu2+ and K+. The EC, TDS, salinity, turbidity, Cl-, NO3-, SO42-, F-, Mn2+ and Cu2+ are higher (pH = 7.44-9.42, EC = 4251.33-15334 µS/cm, TDS = 2079-7526.7 mg/L, salinity = 2.2-8.67 ppt, Cl- = 189.3-3577.6 mg/L, SO42- = 11.83-1353.33 mg/L, F- = 4.68-18 mg/L, Mn2+ = 1.03-2.0 mg/L, Cd2+ = 0.01-0.05 mg/L, Cu2+ = 0.37-0.93 mg/L and K+ = 44-100 mg/L) in hot springs than borehole waters (pH = 6.36-6.58, EC = 270.0-2674.64 µS/cm, TDS = 123.67-1305 mg/L, salinity = 0.03-1.37 ppt, Cl- = 6.25-659.93 mg/L, SO42- = 28.92-493.33 mg/L, F- = 0.89-3.0 mg/L, Mn2+ = 0.3-1.70 mg/L Cd2+ = 0 mg/L, Cu2+ = 0.49-0.64 mg/L and K+ = 16-52 mg/L). The t-test at the probability 0.05 showed that there is significant difference of the parameters pH and Ni2+ between hot spring and borehole waters. Some of the parameters are at higher levels than permissible values for both hot spring and borehole waters. Therefore, there is a need of treatment for these waters before using for domestic purpose.
Abstract: This study conducted for the comparison of physico-chemical parameters between hot springs and borehole waters. Fourteen samples were collected at Mara, Shinyanga and Manyara in Tanzania. Multimeter used for the analysis of physical parameters pH, EC, TDS, salinity and turbidity. Titrimetric methods were used for the determination of Cl-, total har...
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