In this study, the quantitative determination of gaseous biogenic volatile organic compounds (BVOCs) including monoterpenes and sesquiterpenes was accomplished using a solid-phase extraction-type collection device. The collection device was fabricated by packing styrene-divinylbenzene polymer particles into a specially designed glass cartridge. The retention performance of the collection device for BVOCs was quantitatively evaluated at 35°C with different volumes of air samples. The device showed good retention performance for the investigated BVOCs, that is, no breakthrough occurred for monoterpenes up to an air sampling volume of 150 L or for sesquiterpenes up to a sampling volume of 30,000 L. The elution performance was evaluated by passing organic solvents into the collection device, and an excellent elution recovery was obtained with 10 mL dichloromethane. Finally, the analytical method using the collection device was applied to determine the gaseous monoterpenes and sesquiterpenes from a grated carrot and the air inside a wooden house, and the results demonstrated the applicability of the method for the quantitative determination of BVOCs in several sample matrices.
We optimized several analytical conditions for more sensitive and precise HT-RPLC analysis of the therapeutic monoclonal antibody (mAb), bevacizumab. Specifically, we (1) optimized the sample preparation process to reduce adsorption and aggregation of bevacizumab, (2) introduced a sample concentration process using a centrifugal ultrafiltration unit to increase detection sensitivity, and (3) used another therapeutic mAb as an internal standard to improve analytical precision. The optimized method for bevacizumab analysis was shown to have low detection and quantification limits of 0.010 and 0.032 µg/mL, respectively, good correlation coefficients (r2 > 0.9997), and good intra- and inter-day precisions within < 12.0 %. This study provides an important methodology for the intact bioanalysis of therapeutic mAbs, not merely their LC measurement.