Piperazine chemical solvent

In addition to the equipment properties and selected operating conditions, the process performance depends to a large extent on the state of the active solvent component(s). Commonly nsed solvents include physical solvents like methanol (Rectisol) and the dimethyl ethers of polyethylene glycol (Selexol), chemical solvents like aqneous solutions of carbonates such as K2CO3 and Na2C03, of amino acid salts such as mixtures of potassium hydroxide and alanine or tanrine, and especially of alkanolamines such as mono-ethanolamine (MEA), di-ethanolamine (DEA), (activate) methyl-di-ethanolamine (MDEA), di-isopropanolamine (DIPA), di-glycolamine (DGA), 2-amino-2-methyl-l-propanol (AMP), and piperazine (PZ) (1). 

Piperazine (C4H10N2, shown below), is a chemical solvent that reacts with CO2 with fast, second-order kinetics [24]. 

Sigma Chemical Co. Standard protein solutions were prepared in water. Standard solutions were made for each protein of 10 mg dissolved in 1 L with water. The water was filtered with HA 0.5 xm membranes (Division of Millipore, Waters Co., Milford, Massachusetts, U.S.A.) and deionized prior to use. The extra pure grade solvent of ACN was purchased from Duksan Pure Chemicals Company (Incheon, Korea). TEA was purchased from Sigma Chemical Co. The sample for injection was filtered with 0.45 p.m polyvinylidene fluoride (PVDF) (Waters Co.). Sodium chloride and hydrochloric acid were purchased from Duksan Pure Chemicals Company. Piperazine was purchased from Sigma Chemical Co. For the anion exchange membrane, buffer A was 20 mm piper-azine-HCl, pH 6.4, and buffer B was made by addition of 1 M NaCl to buffer A. The mobile phases for RP-HPLC were as follows buffer A, 0.1% TEA in water and buffer B, 0.1% TEA in ACN. 

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