scholarly journals Optimization of the HS-SPME technique by using response surface methodology for evaluating chlorine disinfection by-products by GC in drinking water

2011 ◽  
Vol 22 (12) ◽  
pp. 2330-2336 ◽  
Author(s):  
Mauricio Aguirre-González ◽  
Gonzalo Taborda-Ocampo ◽  
Carmen Dussan-Lubert ◽  
Cristina Nerin ◽  
Milton Rosero-Moreano
2018 ◽  
Vol 8 (4) ◽  
pp. 740-751 ◽  
Author(s):  
Romana Khan ◽  
Imran Hashmi ◽  
Habib Nasir ◽  
Sajida Rasheed ◽  
Luiza C. Campos

Abstract Trihalomethanes (THMs) are regulated disinfection by-products (DBPs), analyzed in drinking water due to their toxicological health effects. However, few data exist regarding the content of emerging THMs in drinking water, which are present at very low concentrations. This study aimed to monitor hazardous and emerging THMs from drinking water supply in a residential area via solid phase microextraction using gas chromatography. Response surface methodology was employed to evaluate the role of salt concentration, temperature, desorption and extraction times on THM formation as a result of raw water prechlorination. Maximum THM detection was achieved at 3.25 g Na2SO4 salt via 30 min extraction time at 80 °C along with 8 min of desorption time. The quantification results revealed the presence of total THMs in all drinking water samples, while most of the sites (88%) exceeded the permissible limit set by the United States Environmental Protection Agency (USEPA). Among I-THMs, chloroiodomethane was found to be dominant as detected in 79% of samples.


2020 ◽  
Vol 83 (1) ◽  
pp. 85-92
Author(s):  
Mohd Azahar Mohd Ariff ◽  
Muhammad Syafiq Abd Jalil ◽  
Noor ‘Aina Abdul Razak ◽  
Jefri Jaapar

Caesalpinia sappan linn. (CSL) is a plant which is also known as Sepang tree contains various medicinal values such as to treat diarrhea, skin rashes, syphilis, jaundice, drinking water for blood purifying, diabetes, and to improve skin complexion. The aim of this study is to obtain the most optimum condition in terms of the ratio of sample to solvent, particle size, and extraction time to get the highest amount of concentration of the CSL extract. In this study, the ranges of each parameters used were: ratio sample to solvent: 1.0:20, 1.5:20, 2.0:20, 2.5:20, 3.0:20, particle size: 1 mm, 500 um, 250 um, 125 um, 63 um, and extraction time: 1 hr, 2 hr, 3 hr, 4 hr, 5 hr. The concentration was analyzed using a UV-vis spectrophotometer. The optimum conditions were obtained by response surface methodology. From the design, 20 samples were run throughout this experiment. The optimized value from the RSM were 2.0:20 for ratio sample to solvent, 125 µm of particle size and 2.48 hours with the concentration of 37.1184 ppm. The accuracy of the predictive model was validated with 2 repeated runs and the mean percentage error was less than 3%. This confirmed the model’s capability for optimizing the conditions for the reflux extraction of CSL’s wood.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1139 ◽  
Author(s):  
Gabriela Aguilar-Hernández ◽  
María de los Ángeles Vivar-Vera ◽  
María de Lourdes García-Magaña ◽  
Napoleón González-Silva ◽  
Alejandro Pérez-Larios ◽  
...  

The soursop fruit or Annona muricata (A. muricata) fruit is recognized by its bioactive compounds and acetogenins (ACG) are among the most important. The effect of ACGs, with greater importance in health, is that they present anti-tumor activity; however, the methods of extraction of ACGs are very slow and with a high expenditure of solvents. To our knowledge, there is no report of an optimal method for the extraction of acetogenins from the Annonaceae family by ultrasound-assisted extraction (UAE); therefore, the aim was to find the best UEA conditions of acetogenins from A. muricata fruit (peel, pulp, seed, and columella) by using response surface methodology. The effect of amplitude (40%, 70%, and 100%), time (5, 10, and 15 min), and pulse-cycle (0.4, 0.7, and 1 s) of ultrasound at 24 kHz was evaluated on the total acetogenin content (TAC). Optimal extraction conditions of acetogenins (ACGs) with UEA were compared with the extraction of ACGs by maceration. The optimal UEA conditions in the A. muricata pulp and by-products were dependent on each raw material. The highest TAC was found in the seed (13.01 mg/g dry weight (DW)), followed by the peel (1.69 mg/g DW), the pulp (1.67 mg/g DW), and columella (1.52 mg/g DW). The experimental TAC correlated well with the model (Adjusted R2 with values between 0.88 and 0.97). The highest effectiveness in ACG extraction was obtained in seeds and peels using UEA compared to extraction by maceration (993% and 650%, respectively). The results showed that A. muricata by-products are an important source of ACGs and that UAE could be a viable alternative, with high potential for large-scale extraction.


2010 ◽  
Vol 121 (2) ◽  
pp. 627-633 ◽  
Author(s):  
Riadh Ben Salah ◽  
Kacem Chaari ◽  
Souhail Besbes ◽  
Naourez Ktari ◽  
Christophe Blecker ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document