The volatile components of Murraya koenigii fresh leaves, collected from Surat Thani province, Thailand were studied by using headspace (HS) solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The four fibers employed to extract the volatiles were polydimethylsiloxane (PDMS), polydimethylsiloxane-divinylbenzene (PDMS-DVB), carboxane-polydimethylsiloxane (CAR-PDMS) and polydimethylsiloxane-divinylbenzene-carboxane (PDMS-DVB-CAR). The volatile constituents of M. koenigii fresh leaves were also extracted by hydrodistillation and analyzed by GC-MS. Fifty-one compounds were identified by these fibers. Five major compounds, -terpinene, -caryophyllene, -phellandrene, -selinene and -pinene, were detected in all fibers. The PDMS-DVB-CAR fiber was considered as the best for trapping key volatiles of M. koenigii fresh leaves.

Negative chromatography antibody purification (N-CAP) using the weak anion exchanger STREAMLINE™ DEAE to extract impurities while retaining the target antibody is proposed as an effective method for the recovery of antibody from rabbit serum. The effects of pH and initial protein concentration on the removal of albumin were investigated. The optimal pH and initial protein concentration for the efficient removal of albumin from rabbit serum were pH 8.0 and 0.5 mg/ml, respectively. Under optimal binding conditions, DEAE successfully removed more than 90% of the albumin from rabbit serum with less than 20% IgG loss. This process offered good polyclonal IgG yield of 80% with a purity of 83% and a purification factor of 5.5. The use of a strong anion exchanger like STREAMLINE™ Q XL for albumin removal was also explored. Under similar optimized conditions, albumin removal by Q XL was as high as 90%. However, IgG recovery and purity were reduced to about 70% and 62%, respectively. Thus, N-CAP using the anion exchanger DEAE removes albumin from rabbit serum and thereby offers an efficient means of purifying polyclonal antibodies.

a b s t r a c tThe applicability of dye-ligands attached to an expanded bed chromatography quartz base matrix (Streamline TM ) for the affinity bioseparation of rabbit immunoglobulin G (IgG) was investigated. Reactive Green 5 (RG-5) immobilized onto adsorbent was selected for capturing of rabbit-IgG due to its higher binding capacity compared to other dye-ligands possessing similar ligand density. Adsorption parameters such as pH, temperature, ionic strength and initial rabbit-IgG concentration were optimized for the adsorption of rabbit-IgG on the RG-5-immobilized adsorbent. The highest rabbit-IgG adsorption was recorded in pH 7.0, while the maximum binding capacity for BSA was achieved at pH 4.0. The adsorption of rabbit-IgG on RG-5-immobilized adsorbent was declined as the increase of ionic strength. There is no significant influence of temperature against adsorption efficiency of RG-5-immobilized adsorbent for rabbit-IgG. The adsorption phenomenon of rabbit-IgG on RG-5-immobilized adsorbent appeared to follow the Langmuir-Freundlich adsorption isotherm model. The theoretically maximum binding capacity (q m ) of RG-5-immobilized adsorbent estimated from this isotherm was 49.3 mg ml −1 , which is very close to that obtained experimentally (49.0 mg ml −1 ). About 50% of bound BSA on RG-5-immobilized adsorbent in binary adsorption system was removed with washing buffer containing 1 M NaCl.