Clavulanic acid separation on fixed bed columns of layered double hydroxides: optimization of operating parameters using breakthrough curves

The adsorption of clavulanic acid (CA) in a fixed-bed column of layered double hydroxides (LDHME) was investigated. Breakthrough curves were obtained experimentally and the system was evaluated with regards to column operation time, efficiency and productivity as functions of simultaneous variations of superficial velocity (vz) and bed height (L) using a central composite rotatable design (CCRD). At the optimized condition (vz = 1.00 cm/min and L = 6.5 cm), the responses were: 46 min, 146 min, 100 min and 13 kg/h cm3, for breakthrough time (tb), exhaustion time (te), the difference te − tb and productivity (P), respectively. These results represent no change in tb, but a 50% decrease of te, 40% decrease of (te − tb) and 38% increase of P, which is advantageous for the process. The factorial design technique was shown to be an efficient tool for assessing factor influences and was effective in optimizing the column operating conditions. Good separation of CA from the amino acids tyrosine (TYR) and proline (PRO) was observed in fixed bed columns. The LDHME adsorbent was shown to be an excellent alternative for CA purification514509516COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPBEX 6843/10-72008/57298-

Development and characterization of a new adsorbent for biomolecule separation: intercalation and adsorption of clavulanic acid in layered double hydroxides

A new layered double hydroxide (LDH) material has been developed through a pioneering approach, with the goal of being an alternative adsorbent for the separation of biomolecules, such as clavulanic acid (CA). RESULTSZn2Cr‐CA hybrid LDH assemblies were prepared through a coprecipitation method to evaluate the affinity between the CA molecule and the interlayer sites. The resulting inorganic–organic ‘sandwich’ structure was characterized by a combination of techniques showing an expansion of the layered structure from 0.78 nm up to values of 2.30 nm upon CA intercalation. Isotherm studies were carried out to evaluate the adsorption capacity of LDH towards CA. The Freundlich adsorption model was found to fit the experimental data well, indicating a relatively large adsorption capacity for the adsorbent Zn2Cr‐NO3, as high as 73.63, 128.76, and 229.62 mg1‐nFLnFg−1 at 20, 30, and 35 °C, respectively. CONCLUSION Zn2Cr‐NO3 adsorption capacity was not influenced by the presence of amino acids, thus underlining that it is a LDH composition which may be a suitable alternative for the separation of CA. LDH micro‐particles were additionally encapsulated with calcium alginate gel (LDHME) and characterized for particle average diameter (dp = 171 µm), bulk density (ρbulk = 0.63 g cm−3), particle density (ρp = 2.2 g cm−3), particle porosity (ϵp = 0.71) and bed porosity (ϵB = 0.40). The application of LDHME in the separation of CA from complex mixtures, containing tyrosine and proline, was considered satisfactory based on purification factors of about 2.32 and degrees of purity higher than 99%91617091719COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP6843/10-72008/57298-

Development and characterization of a new adsorbent for biomolecule separation: intercalation and adsorption of clavulanic acid in layered double hydroxides.

International audienceBACKGROUNDA new layered double hydroxide (LDH) material has been developed through a pioneering approach, with the goal of being an alternative adsorbent for the separation of biomolecules, such as clavulanic acid (CA).RESULTSZn2Cr-CA hybrid LDH assemblies were prepared through a coprecipitation method to evaluate the affinity between the CA molecule and the interlayer sites. The resulting inorganic–organic ‘sandwich’ structure was characterized by a combination of techniques showing an expansion of the layered structure from 0.78 nm up to values of 2.30 nm upon CA intercalation. Isotherm studies were carried out to evaluate the adsorption capacity of LDH towards CA. The Freundlich adsorption model was found to fit the experimental data well, indicating a relatively large adsorption capacity for the adsorbent Zn2Cr-NO3, as high as 73.63, 128.76, and 229.62 mg1-nFLnFg−1 at 20, 30, and 35 °C, respectively.CONCLUSIONZn2Cr-NO3 adsorption capacity was not influenced by the presence of amino acids, thus underlining that it is a LDH composition which may be a suitable alternative for the separation of CA. LDH micro-particles were additionally encapsulated with calcium alginate gel (LDHME) and characterized for particle average diameter (dp = 171 µm), bulk density (ρbulk = 0.63 g cm−3), particle density (ρp = 2.2 g cm−3), particle porosity (ϵp = 0.71) and bed porosity (ϵB = 0.40). The application of LDHME in the separation of CA from complex mixtures, containing tyrosine and proline, was considered satisfactory based on purification factors of about 2.32 and degrees of purity higher than 99%. © 2015 Society of Chemical Industr

Clavulanic acid separation on fixed bed columns of layered double hydroxides: Optimization of operating parameters using breakthrough curves

International audienceThe adsorption of clavulanic acid (CA) in a fixed-bed column of layered double hydroxides (LDHME) was investigated. Breakthrough curves were obtained experimentally and the system was evaluated with regards to column operation time, efficiency and productivity as functions of simultaneous variations of superficial velocity (vz) and bed height (L) using a central composite rotatable design (CCRD). At the optimized condition (vz = 1.00 cm/min and L = 6.5 cm), the responses were: 46 min, 146 min, 100 min and 13 kg/h cm3, for breakthrough time (tb), exhaustion time (te), the difference te − tb and productivity (P), respectively. These results represent no change in tb, but a 50% decrease of te, 40% decrease of (te − tb) and 38% increase of P, which is advantageous for the process. The factorial design technique was shown to be an efficient tool for assessing factor influences and was effective in optimizing the column operating conditions. Good separation of CA from the amino acids tyrosine (TYR) and proline (PRO) was observed in fixed bed columns. The LDHME adsorbent was shown to be an excellent alternative for CA purification

No impact of passive smoke on the somatic profile of lung cancers in never-smokers

International audienceEGFR and HER2 mutations and ALK rearrangement are known to be related to lung cancer in never-smokers, while KRAS, BRAF and PIK3CA mutations are typically observed among smokers. There is still debate surrounding whether never-smokers exposed to passive smoke exhibit a "smoker-like" somatic profile compared with unexposed never-smokers. Passive smoke exposure was assessed in the French BioCAST/IFCT-1002 never-smoker lung cancer cohort and routine molecular profiles analyses were compiled. Of the 384 patients recruited into BioCAST, 319 were tested for at least one biomarker and provided data relating to passive smoking. Overall, 219 (66%) reported having been exposed to passive smoking. No significant difference was observed between mutation frequency and passive smoke exposure (EGFR mutation: 46% in never exposed versus 41% in ever exposed; KRAS: 7% versus 7%; ALK: 13% versus 11%; HER2: 4% versus 5%; BRAF: 6% versus 5%; PIK3CA: 4% versus 2%). We observed a nonsignificant trend for a negative association between EGFR mutation and cumulative duration of passive smoke exposure. No association was found for other biomarkers. There is no clear association between passive smoke exposure and somatic profile in lifelong, never-smoker lung cancer