Experimental Design in Analytical Chemistry—Part I: Theory

2014 ◽  
Vol 97 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Heshmatollah Ebrahimi-Najafabadi ◽  
Riccardo Leardi ◽  
Mehdi Jalali-Heravi
Keyword(s):  
Analytical Chemistry ◽  
Response Surface Methodology ◽  
Experimental Design ◽  
Response Surface ◽  
Fractional Factorial ◽  
Factorial Designs ◽  
Fractional Factorial Designs ◽  
Central Composite

Abstract This paper reviews the main concepts of experimental design applicable to the optimization of analytical chemistry techniques. The critical steps and tools for screening, including Plackett-Burman, factorial and fractional factorial designs, and response surface methodology such as central composite, Box-Behnken, and Doehlert designs, are discussed. Some useful routines are also presented for performing the procedures.

Optimization of Critical Medium Components for the Expression of Recombinant Human Transferrin in Insect Cells Baculovirus System

2012 ◽  
Author(s):  
Clarence M. Ongkudon ◽  
Badarulhisam Abdul Rahman ◽  
Azila Abd. Aziz
Keyword(s):  
Response Surface Methodology ◽  
Experimental Design ◽  
Central Composite Design ◽  
Response Surface ◽  
Insect Cells ◽  
Expression System ◽  
Proliferating Cells ◽  
Human Transferrin ◽  
Lipid Mixtures ◽  
Central Composite

Transferin manusia (hTf) memainkan peranan yang penting dalam fungsi bakteriostatik dan pengangkutan ferum dari bahagian penyimpanan ke sel–sel yang membiak melalui proses endositosis janaan reseptor. Sistem ekspresi bakulovirus sel serangga telah dipakai secara meluas sebagai sistem alternatif dalam penghasilan Transferin manusia rekombinan (rhTf). Kajian ini ditumpukan ke atas pengoptimuman glutamina, glukosa dan campuran lipid 1000x yang dapat meningkatkan penghasilan rhTf. Reka bentuk eksperimen yang melibatkan 17 eksperimen reka bentuk komposit berpusat (CCD) telah digunakan dan hasil kajian dianalisis oleh Statistika (Statsoft v. 5.0). Metodologi permukaan tindak balas (RSM) telah mengenalpasti nilai optimum parameterparameter yang dikaji iaitu glutamina=2211.20 mg/L, glukosa=1291.95 mg/L, dan campuran lipid 1000x=0.64 %v/v. Hasil optimasi menunjukkan peningkatan hasil rhTf sebanyak tiga kali ganda, iaitu daripada 19.89 μg/ml kepada 65.12 μg/ml. Kata kunci: Transferin manusia; bakulovirus sel serangga; reka bentuk eksperimen; reka bentuk komposit berpusat; metodologi permukaan tindak balas Human Transferrin (hTf) plays a big role in providing bacteriostatic functions as well as to transport iron from the storage part to all proliferating cells by receptor mediated endocytosis. Insect cells baculovirus expression system has been widely used as an alternative expression system for the production of recombinant human Transferrin (rhTf). This work focused mainly on the optimization of glutamine, glucose and lipid mixtures 1000x to increase rhTf yield. An experimental design involving 17 central composite design (CCD) experiments was employed and results were analyzed by Statistica (Statsoft v. 5.0). The response surface methodology (RSM) had identified the optimum values where glutamine=2211.20 mg/L, glucose=1291.95 mg/L, and lipid mixtures 1000x=0.64 %v/v. Using the optimized parameters, the studies demonstrated an increase in the rhTf yield by three–fold from 19.89 μg/ml to 65.12 μg/ml. Key words: Human transferrin; insect cells baculovirus; experimental design; central composite design; response surface methodology

scholarly journals Response Surface Methodology for the Optimisation of Electrochemical Biosensors for Heavy Metals Detection

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 26 ◽  
Author(s):  
Giuseppe De Benedetto ◽  
Sabrina Di Masi ◽  
Antonio Pennetta ◽  
Cosimino Malitesta
Keyword(s):  
Response Surface Methodology ◽  
Experimental Design ◽  
Response Surface ◽  
Enzyme Concentration ◽  
Experimental Parameters ◽  
Number Of Cycles ◽  
Metal Ions Detection ◽  
First Time ◽  
Central Composite ◽  
Biosensor Response

Herein, we report the application of a chemometric tool for the optimisation of electrochemical biosensor performances. The experimental design was performed based on the responses of an amperometric biosensor developed for metal ions detection using the flow injection analysis. The electrode preparation and the working conditions were selected as experimental parameters, and thus, were modelled by a response surface methodology (RSM). In particular, enzyme concentration, flow rates, and number of cycles were reported as continuous factors, while the sensitivities of the biosensor (S, µA·mM−1) towards metals, such as Bi3+ and Al3+ were collected as responses and optimised by a central composite design (CCD). Bi3+ and Al3+ inhibition on the Pt/PPD/GOx biosensor response is for the first time reported. The optimal enzyme concentration, scan cycles and flow rate were found to be 50 U·mL−1, 30 and, 0.3 mL·min−1, respectively. Descriptive/predictive performances are discussed: the sensitivities of the optimised biosensor agreed with the experimental design prediction. The responses under the optimised conditions were also tested towards Ni2+ and Ag+ ions. The multivariate approach used in this work allowed us to obtain a wide working range for the biosensor, coupled with a high reproducibility of the response (RSD = 0.72%).

scholarly journals Bioproduction of riboflavin by fungi using spent industrial oils

2011 ◽  
Author(s):  
◽  
Nazihah Khan
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Vegetable Oil ◽  
Yeast Extract ◽  
Fractional Factorial ◽  
Experimental Designs ◽  
Malt Extract ◽  
Motor Oil ◽  
Candida Famata ◽  
Central Composite

Riboflavin (vitamin B2), an essential water-soluble vitamin is commercially produced because it cannot be synthesized by vertebrates. Although this vitamin is produced chemically, bioproduction is a better option since it is more economical, requires less energy, produces less waste and can use renewable sources. In this study we investigated spent oil from the food and motor industries as alternative cheap carbon sources for the bioproduction of this vitamin. Commercial fungal strains namely; Eremothecium gossypii ATCC 10895, Eremothecium gossypii CBS 109.51, Eremothecium ashbyi CBS 206.58 and the yeast, Candida famata ATCC 20850, as well as a laboratory mutated Eremothecium gossypii EMS 30/1 strain were used. Statistical experimental design using a series of fractional factorial experimental designs was used to optimize the effect of yeast extract, peptone, malt extract, K2HPO4 and MgSO4.7H2O to supplement the used oils for optimum riboflavin production. Response surface methodology based on central composite experimental designs was then applied and together with the point predictions made, production media for both substrates were further optimized. The optimized conditions were then tested with laboratory experiments. Results showed that mutant E. gossypii EMS 30/1 produced the most riboflavin in spent motor oil (20.45 mg.l-1) while Candida famata ATCC 20850 produced the highest concentration (16.99 mg.l-1) in spent vegetable oil. With these strains and using the experimental designs from the fractional factorial experiments, supplemented spent motor and spent vegetable oils produced 66.27 mg.l-1 and 72.50 mg.l-1 riboflavin, respectively. The central composite optimization results showed that 0.18 g.l-1 and 0.45 g.l-1 K2HPO4 and 12.5 g.l-1 malt extract increased the production to 91.88 mg.l-1 and 78.68 mg.l-1 in spent vegetable oil and motor oil respectively. A point prediction from the response surface methodology was used to validate these and it was found that 103.59 mg.l-1 riboflavin was produced by mutant E. gossypii EMS 30/1 using 2.5 g.l-1 yeast extract, 0.5 g.l-1 peptone, 12.5 g.l-1 malt extract, 0.18 g.l-1 K2HPO4 and 0.3 g.l-1 MgSO4.7H2O. After optimizing K2HPO4 in a one-factor-at-a-time experiment, 82.75 mg.l-1 riboflavin was produced by C. famataon v SVO using 6.5 g.l-1 peptone, 12.5 g.l-1 malt extract 0.15 g.l-1 K2HPO4 and 1.75 g.l-1 MgSO4.7H2O. This is a 5.08 and 4.87 fold increase respectively when compared to spent oil prior to optimization. This shows that spent motor oil and mutant E. gossypii produces 103.59 mg.l-1 riboflavin while spent vegetable oil and C. famata produces 82.75 mg.l-1 riboflavin. Hence, E. gossypii can be used to generate riboflavin using spent motor oil and C. famata, using spent vegetable oil.

scholarly journals OPTIMASI FERMENTASI BAGAS TEBU OLEH Zymomonas mobilis CP4 (NRRL B-14023) UNTUK PRODUKSI BIOETANOL (Optimization of Sugarcane Bagasse Fermentation by Zymomonas mobilis CP4 (NRRL B-14023) for Bioethanol Production)

2014 ◽  
Vol 34 (03) ◽  
pp. 247 ◽  
Author(s):  
Atmiral Ernes ◽  
Lia Ratnawati ◽  
Agustin Krisna Wardani ◽  
Joni Kusnadi
Keyword(s):  
Response Surface Methodology ◽  
Experimental Design ◽  
Response Surface ◽  
Sugarcane Bagasse ◽  
Zymomonas Mobilis ◽  
Urea Concentration ◽  
Fermentation Time ◽  
Inoculum Concentration ◽  
Central Composite Experimental Design ◽  
Central Composite

Second generation bioethanol can be produced from fermentation of natural renewable materials, such as agricultural crops, as well as from industrial and domestic waste. The present study was aimed to optimize the fermentation process (inoculum concentration, urea concentration, and fermentation time) for ethanol production from sugarcane bagasse byZymomonas mobilis CP4 using response surface methodology (RSM) central composite experimental design (CCD). The RSM model predicted the optimum value of ethanol content was 1.257% (v/v) at inoculum concentration 15% (v/v), urea concentration 0.3% (w/v), and fermentation time 45 h. Based on the experiment, the ethanol concentrationwas 1.213% (v/v), which was in close agreement with the predicted value. Ethanol yield of this experiment was 0.479 with fermentation effi ciency of 93.9%. The results presented here proved a signifi cant contribution of Z. mobilis CP4 to the production of bioethanol from sugarcane bagasse.Keywords: Bioethanol, sugarcane bagasse, Zymomonas mobilis CP4, fermentation optimization ABSTRAKBioetanol generasi kedua dapat diproduksi dari fermentasi bahan terbarukan, seperti produk hasil pertanian, dan limbah atau hasil samping pengolahan industri dan rumah tangga. Tujuan penelitian ini adalah optimasi parameter fermentasi yang meliputi konsentrasi inokulum, konsentrasi urea, dan lama fermentasi untuk produksi etanol dari bagas tebu oleh Zymomonas mobilis CP4 dengan menggunakan response surface methodology (RSM) central composite experimental design (CCD). Kondisi respon yang optimal berdasarkan prediksi model diperoleh pada konsentrasi inokulum 15% (v/v), konsentrasi urea 0,3% (b/v), dan lama fermentasi 45 jam, dengan prediksi respon kadar etanol sebesar 1,257%(v/v). Berdasarkan hasil penelitian, kadar etanol optimal diperoleh sebesar 1,213% (v/v), yang menunjukkan hasil yang tidak berbeda jauh dengan prediksi model. Yield etanol yang diperoleh sebesar 0,479 dengan efi siensi fermentasi 93,9%. Hasil penelitian ini membuktikan bahwa strain bakteri Zymomonas mobilis CP4 memiliki potensi yang cukup menjanjikan sebagai mikroba penghasil etanol.Kata kunci: Bioetanol, bagas tebu, Zymomonas mobilis CP4, optimasi fermentasi

Enzyme-assisted Extraction for Optimized Recovery of Phenolic Bioactives from Peganum hermala Leaves Using Response Surface Methodology

2018 ◽  
Vol 17 (4) ◽  
pp. 349-354
Author(s):  
Qadir Rahman ◽  
Anwar Farooq ◽  
Amjad Gilani Mazhar ◽  
Nadeem Yaqoob Muhammad ◽  
Ahmad Mukhtar
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Enzyme Concentration ◽  
Coumaric Acid ◽  
Assisted Extraction ◽  
Pre Treatment ◽  
Optimized Conditions ◽  
Enzyme Complexes ◽  
Hydrolysis Of ◽  
Central Composite

This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuzyme) on recovery of phenolics from Peganum hermala (harmal) leaves, under optimized conditions using response surface methodology. As compared to the other enzyme complexes, the yield (34 g/100g) obtained through Zympex-014-assisted extraction was higher under optimized conditions such as time (75 min), temperature (70°C), pH (6.5) and enzyme concentration (5 g/100 g) using central composite design (CCD). Effectiveness of Zympex-014 towards hydrolysis of P. hermala leaves cell wall was examined by analyzing the control and enzyme-treated leave residues using scanning electron microscope (SEM). GC/MS characterization authenticated the presence of quercetin (1.44), gallic acid (0.23), caffeic acid (0.04), cinnamic acid (0.05), m-coumaric acid (0.23) and p-coumaric acid (0.37 μg/g) as the potent phenolics in Zympex-014 based extract. It can be concluded from the findings of the current work that pre-treatment of P. hermala leaves with Zympex-014 significantly enhanced the recovery of phenolics that supports its potential uses in the nutra-pharamaceutical industry.

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