[Simultaneous Analysis of 7 Antiviral Agents in Chicken Tissues and Processed Products by LC-MS/MS].

Since amantadine, rimantadine, arbidol, laninamvir, oseltamivir, peramivir, and zanamivir may be used as antiviral agents to treat avian influenza, we herein developed a simultaneous assay using LC-MS/MS. This method was applied to chicken products (including yakitori (grilled chicken), fried chicken, chicken steak, and boiled eggs) as well as chicken tissues (muscle, fat, the liver, gizzards, and heart) and eggs.Samples were extracted with methanol-water (9 : 1), purified by a tandem column with an InertSep® MAX cartridge (upper part) and InertSep® MCX cartridge (lower part), and then measured by LC-MS/MS. The sample matrix had no effect on the identification of compounds. Chromatographic separation was performed on a ZIC-HILIC column using a mobile phase of 1% acetic acid solution and 1% acetic acid solution in acetonitrile, resulting in complete separation and other obstructive peaks from the sample matrices. An external solvent calibration curve was used for quantification.The application of the method to 6 samples of chicken tissues and eggs achieved good results of between 77.9 and 97.5% for trueness and between 1.7 and 9.2% for concurrent accuracy. The method was also applied to 9 samples of processed products, including grilled chicken and fried chicken, and achieved good results with true percentages ranging between 72.6 and 99.2% and concurrent accuracies between 3.0 and 11.2%. Therefore, the developed method may also be applied to processed products.The limit of quantification (LOQ) of the developed method was 0.01 mg/kg.The method was then applied to 42 types of commercial processed products, including yakitori, fried chicken, steamed chicken, chicken steak, and boiled eggs, and no antiviral agents were detected.Collectively, the present results confirmed that the method developed herein is applicable to not only chicken tissues, but also their processed products.

[Determination of Zilpaterol in Livestock Products by LC-MS/MS].

An analytical method for the determination of zilpaterol in livestock products was developed. The sample was stirred with n-hexane and n-hexane saturated acetonitrile, and zilpaterol in the sample was extracted with acetonitrile. The extract was cleaned up on a ODS cartridge column (1 g) and SCX cartridge column (500 mg). The LC separation was carried out using an Inertsil ODS-4 column and linear gradient elution with 0.1%formic acid and acetonitrile containing 0.1% formic acid as mobile phase. Detection of MS was carried out positive ion electrospray ionization mode. Average recoveries (n=5) of zilpaterol from 6 kinds of livestock products fortified at the MRLs (0.01 mg/kg) were 87.0-99.4%, and the relative standard deviations were 2.4-6.3%. The limits of quantitation were 0.01 mg/kg.

Determination of Diniconazole in Agricultural Products, Livestock and Marine Products by LC-MS/MS.

An LC-MS/MS method for the determination of diniconazole in agricultural products, livestock and marine products was developed. Diniconazole in agricultural products was extracted with acetone. The extract was concentrated and partitioned with n-hexane and 10% sodium chloride solution. Agricultural products such as grains and beans were defatted using n-hexane-acetonitrile. Livestock and marine products were extracted with a mixture of acetone and n-hexane, and the organic layer was evaporated to dryness. The residue was defatted using n-hexane-acetonitrile. Cleanup was carried out using a Florisil cartridge column and a graphitized carbon cartridge column for these samples. The LC separation was carried out on an Inertsil ODS-3 column with a linear gradient of 0.1% formic acid and acetonitrile containing 0.1% formic acid. MS was carried out in the positive ion electrospray ionization mode. The calibration curve was linear between 0.00125 to 0.00750 mg/L. Average recoveries (n=5) of diniconazole from 16 kinds of agricultural products, livestock and marine products fortified at the MRLs (0.01 ppm) were 88.3-108%, and the relative standard deviations were 0.5-5.1%. The limits of quantitation were 0.01 mg/kg.

Association of peripheral artery disease and long-term mortality in hemodialysis patients.

BACKGROUND: Peripheral artery disease (PAD) is a common complication in hemodialysis patients. The ankle-brachial blood pressure index (ABI) has been widely used to screen for subclinical PAD. In the present study, we investigated the association between ABI and long-term (up to 8.8 years) mortality among hemodialysis patients. METHODS: A total of 86 consecutive patients receiving maintenance hemodialysis who underwent an ABI examination between 2001 and 2003 were retrospectively enrolled in this study. Patients with an ABI of less than 0.9 were considered as having PAD; those with an ABI of more than 0.9 in both legs were considered as being free from PAD. We examined the relationship between mortality and several risk factors. RESULTS: During the follow-up period, 43 deaths were recorded. In the univariate regression analysis, the mortality hazard ratio (HR) of patients with PAD was 1.67 (95% confidence interval [CI], 1.18-2.28). Other predictive variables for mortality included male gender, age, and diabetes mellitus (P = 0.006, P = 0.024, and P = 0.023, respectively). A multivariate Cox analysis identified PAD and male gender as independent predictors of mortality (P = 0.033 and P = 0.028, respectively). The impact of age and diabetes mellitus on mortality was no longer significant in the multivariate analysis. CONCLUSION: After a relatively long-term observation period, a multivariate analysis indicated that PAD acted independently of other risk factors, including advanced age and the presence of diabetes mellitus. ABI measurements can be used to identify high-risk hemodialysis patients requiring intensive follow-up care.