Morphological and anatomical response of Acacia ehrenbergiana Hayne and Acacia tortilis (Forssk) Haynes subspp. raddiana seedlings to induced water stress

The response of Acacia ehrenbergiana Hayne and Acacia tortilis (Forssk) Haynes subspp. raddiana seedlings to 100, 50 and 25% field capacity (FC) watering regimes was studied to determine their morphological and anatomical behaviour. Both species responded morphologically as well as anatomically to water stress. Water stress caused significant (P=0.05) decrease in relative water content, leaf number and area and leaf water potential, chlorophyll content, and stem height and diameter. Seedlings of both species responded to water stress by the development of longer roots. Vessel segment length, radial diameter, tangential diameter, wall thickness and density were significantly (P=0.05) affected by water stress at 25 and 50% FC. It can be concluded that both species can adapt well under dry conditions.Keywords: Anatomical deviations, drought, morphological response, root elongatio

Microwave Assisted Reduction for Screening Banned Aromatic Amines in Azo Dyes

The study proposes a simple, novel and green alternative for the efficient reduction of azo dyes by the standard method, EN 14362-1:2012 (Annex. F) for detection of harmful aromatic amines in colorants, by incorporating microwave heating in place of convective heating. Basic dye response to reduction methods was explored by UV-visible spectroscopy and the results were confirmed through GC-MS and HPLC-DAD. Four azo dyes namely Acid red 1 (AR-1), Direct blue 15 (DB-15), Direct red 28 (DR-28) and Direct red 7 (DR-7) were reduced with sodium dithionite at 70 °C for 30 min in a buffered solution at pH 6.0, serving as a reference method. The decline in dye absorbance after their reduction was explored by UV-visible spectroscopy with carefully chosen bands of maximum absorbance from 300 to 700 nm. The alternative method exposed dye solutions to short microwave heating (10 s) and immediate cooling, in cycles till the desired duration of microwave heating was achieved. Results obtained from reference method were used for comparison with MAR (experimental method 1). Most prominent results of MAR were observed in the case of DR-28 dye. Hence DR-28 was further subjected to the conditions of experimental method 2, which was simply EN 14362-1:2012 (F) method modified with MAR. For standard method and experimental method 2, amines were analysed by GC-MS and HPLC-DAD. MAR methods were compared with reference and standard reduction methods for efficiencies. The total saving with MAR in terms of time and energy was ~70% and ~92% respectively

Microwave Assisted Reduction for Screening Banned Aromatic Amines in Azo Dyes

The study proposes a simple, novel and green alternative for the efficient reduction of azo dyes by the standard method, EN 14362-1:2012 (Annex. F) for detection of harmful aromatic amines in colorants, by incorporating microwave heating in place of convective heating. Basic dye response to reduction methods was explored by UV-visible spectroscopy and the results were confirmed through GC-MS and HPLC-DAD. Four azo dyes namely Acid red 1 (AR-1), Direct blue 15 (DB-15), Direct red 28 (DR-28) and Direct red 7 (DR-7) were reduced with sodium dithionite at 70 °C for 30 min in a buffered solution at pH 6.0, serving as a reference method. The decline in dye absorbance after their reduction was explored by UV-visible spectroscopy with carefully chosen bands of maximum absorbance from 300 to 700 nm. The alternative method exposed dye solutions to short microwave heating (10 s) and immediate cooling, in cycles till the desired duration of microwave heating was achieved. Results obtained from reference method were used for comparison with MAR (experimental method 1). Most prominent results of MAR were observed in the case of DR-28 dye. Hence DR-28 was further subjected to the conditions of experimental method 2, which was simply EN 14362-1:2012 (F) method modified with MAR. For standard method and experimental method 2, amines were analysed by GC-MS and HPLC-DAD. MAR methods were compared with reference and standard reduction methods for efficiencies. The total saving with MAR in terms of time and energy was ~70% and ~92% respectively