Chiareiy Liu

Simultaneous determination of morphine, codeine, 6-acetylmorphine, cocaine and benzoylecgonine in hair by liquid chromatography/electrospray ionization tandem mass spectrometry.

A fast and sensitive liquid chromatography/triple quadrupole tandem mass spectrometry (LC/MS/MS) method was developed for the simultaneous determination of morphine, codeine, 6-acetylmorphine (6-AM), cocaine and benzoylecgonine (BE) in hair. Pulverized hair samples were extracted with methanol, and a 50 microL supernatant aliquot was injected into the LC/MS/MS system. Chromatography was performed with an XBridge phenyl column (3.5 microm particle size, 4.6 x 150 mm), and the mobile phase was composed of methanol and 10 mM ammonium acetate adjusted to pH 4.00 with 99% formic acid (95:5, v/v). A separation run with isocratic elution was completed in 10 min at a flow rate of 500 microL/min. Positive electrospray ionization and multiple reaction monitoring (MRM) with one precursor ion/product ion transition were used for the identification of each analyte. Deuterated analogues as internal standards were used for quantification and qualification. Linearity was established in the concentration range of 100-3000 pg/mg. The limits of detection were 10 pg/mg for morphine, codeine and 6-AM; and 1 pg/mg for cocaine and BE. The precision and accuracy were determined by spiking hair samples at six concentration levels. For all analytes, the relative standard deviations of intra- and inter-day precision were 0.1-6.3% and 1.5-10.6%, respectively. The accuracy ranged from 92.7 to 109.7%. The validated LC/MS/MS method was successfully applied to the analysis of 79 authentic hair samples.

Estimation of the Measurement Uncertainty in Quantitative Determination of Ketamine and Norketamine in Urine Using a One-Point Calibration Method

An approach was proposed for the estimation of measurement uncertainty for analytical methods based on one-point calibration. The proposed approach is similar to the popular multiple-point calibration approach. However, the standard deviation of calibration was estimated externally. The approach was applied to the estimation of measurement uncertainty for the quantitative determination of ketamine (K) and norketamine (NK) at a 100 ng/mL threshold concentration in urine. In addition to uncertainty due to calibration, sample analysis was the other major source of uncertainty. To include the variation due to matrix effect and temporal effect in sample analysis, different blank urines were spiked with K and NK and analyzed at equal time intervals within and between batches. The expanded uncertainties (k = 2) were estimated to be 10 and 8 ng/mL for K and NK, respectively.

Enhancing food safety management in Taiwan

The global food system is being transformed because of increasing trade and travel, changes in agricultural and animal production practices, bacterial resistance to antibiotics, and continuous technology development processes. More food safety issues have arisen in recent years, accompanied by high public concern; thus, food safety has become a new challenge to governments worldwide. In response to multiple food safety issues, the Taiwan Food and Drug Administration (TFDA) was first inaugurated on January 1, 2010. This action was accomplished through reorganization of the Department of Health (DOH). The consensus for better integrating the science of risk assessment into management decisions was depicted first by the “Food Safety and Nutrition White Paper” published in 2008. In 2012, the TFDA adopted the Codex Alimentarius Commission working principles used for food safety risk analysis for application by governments. First, a food safety management system was established. The policy side included law and regulation formulation, standards setting, and risk management