[Improvement of Analytical Method of PCBs by GC-MS/MS Using an Accelerated Solvent Extractor and Expansion of Target Food Products].

We examined the expansion of target food products for the analysis of polychlorinated biphenyls (PCBs). From our studies in fish using an accelerated solvent extractor (ASE) and GC-MS/MS, we found that recovery of low-chlorinated PCBs (some isomer of 3 or 4 chlorinated PCBs) in specific food products was low. Therefore, we attempted to improve the analytical method. In Japanese sea perch (Suzuki) and milk, freeze drying before extracting with ASE did not sufficiently improve the recovery of low-chlorinated PCBs; however, it was significantly improved by changing the column to a silica gel/H2SO4 silica gel multilayer column. To evaluate this method for other food products, PCBs in fish, meat, eggs, milk, and dairy products were analyzed. The samples were extracted using ASE at 125℃ with n-hexane, cleaned up using a silica gel/H2SO4 silica gel multilayer column, and analyzed by GC-MS/MS for 3-7 chlorinated PCBs. The limit of quantification for this method was was 0.03-0.16 µg/kg for the 3-7 chlorinated PCBs. The recovery and the coefficient of variation of 3-7 chlorinated PCBs from each of the food products (n=5) was in the range of 84%-112% and 1%-9%, respectively.

[Determination of Tributyltin and Triphenyltin in Fish and Shellfish Using Accelerated Solvent Extraction and Liquid Chromatography with Tandem Mass Spectrometry].

A determination method for tributyltin (TBT) and triphenyltin (TPT) in fish and shellfish using an accelerated solvent extractor (ASE) and LC-MS/MS was developed. The chromatographic separation was conducted on a Poroshell 120 EC-C18 column using an isocratic mobile phase of 0.1% formic acid in 70% methanol. Sample preparation was performed using ASE at 125℃ with n-hexane and a cleanup using a Florisil cartridge. Internal calibration curves using deuterium-labeled TBT and TPT were employed for quantification. For both TBT and TPT, the calibration curves were linear in the range of 0.2-250 ng/mL, and the method quantification limits were 0.8 ng/g for both TBT and TPT. A National Institute for Environmental Studies certified reference material, No. 15 (adductor muscle of scallop), was analyzed to assess the performance of the developed method. The trueness, relative standard deviations of repeatability, and within laboratory reproducibility of this method, evaluated using a recovery test with four spiked fish species and one shellfish, ranged from 89.3 to 105.3%, 1.0 to 4.5%, and 1.3 to 7.6%, respectively.

[Analytical Method of PCBs in Fishes by GC-MS/MS Using an Accelerated Solvent Extractor].

An analytical method for PCBs in fishes using an accelerated solvent extractor (ASE) and GC-MS/MS was evaluated. After the extraction of ASE at 125℃ with n-hexane and clean-up with an AgNO3 silica gel/H2SO4 silica gel multilayer column, samples were analyzed by GC-MS/MS. This method was fast, effective and easy to operate. The limit of quantitation of the method was calculated to be 0.78 µg/kg for total PCBs. The recovery and the coefficient of variation of PCBs (n=5) from 6 fishes (Japanese sea perch, chub mackerel, yellowtail, salmon, pacific saury, and sardine) of total PCBs were 91-108% and 1-3%, respectively.

Determination of Fluopicolide in Livestock Products and Seafood by LC-MS/MS.

An analytical method for the determination of fluopicolide in livestock products and seafood was developed using LC-MS/MS. Sodium chloride was added to livestock products and seafood samples and fluopicolide was extracted twice with acetone after acidification with formic acid. The fat from the crude extract was removed using a macroporous diatomaceous earth column, followed by purification with a combination of mini-columns of GC (graphite carbon) and PSA (ethylenediamine-N-propyl silylation silica gel). The average recovery (n=5) of fluopicolide from 10 types of livestock products and seafood (cattle fat, cattle liver, cattle muscle, chicken, eel, egg, freshwater clam, honey, milk and salmon) spiked at the MRLs or at the uniform limit (0.01 ppm) was 96-100%, with a relative standard deviation of 2.3-6.2%. The limit of quantitation of the developed method was calculated to be 0.01 mg/kg.

Association of kidney dysfunction with silent lacunar infarcts and white matter hyperintensity in the general population: the Ohasama study.

BACKGROUND: No previous study has investigated the association of kidney dysfunction with silent lacunar infarcts and white-matter hyperintensity (WMH) independent of ambulatory blood pressure (BP). METHODS: A cross-sectional study involving 1,008 participants (mean age 66 years) from a general population of Ohasama, Japan, was conducted. Calculated creatinine clearance (CCr) was estimated using the Cockcroft-Gault equation. In continuous and categorical analyses, the association between CCr and the prevalence of silent lacunar infarcts and WMH was investigated. Silent lacunar infarcts and WMH were detected on MRI. Multiple logistic regression analysis adjusted for 24-hour ambulatory BP, sex, age, body mass index, smoking and drinking status, antihypertensive medication, and histories of hypercholesterolemia, diabetes mellitus and heart disease was performed. RESULTS: On univariate analysis, decreased CCr (continuous variable) and CCr <60 ml/min/1.73 m(2) (categorical variable) were significantly associated with lacunar infarcts and WMH. After adjustment, each 1-standard-deviation decrease in CCr (odds ratio = 1.22; p = 0.036) and CCr <60 ml/min/1.73 m(2) (odds ratio = 1.68; p = 0.007) was significantly associated with a high prevalence of lacunar infarcts. Even when 24-hour ambulatory BP was within the normal range (<130/80 mm Hg), CCr <60 ml/min/1.73 m(2) was associated with a high prevalence of lacunar infarcts (odds ratio = 1.62; p = 0.047). CCr <60 ml/min/1.73 m(2) and 24-hour ambulatory BP had additive effects on lacunar infarcts. After the same adjustment, the association between CCr and WMH was not significant. CONCLUSIONS: CCr is closely associated with lacunar infarcts, suggesting that kidney dysfunction in the elderly is an independent risk factor or predictor for silent lacunar infarcts.

Detection of carotid atherosclerosis in individuals with masked hypertension and white-coat hypertension by self-measured blood pressure at home: the Ohasama study.

OBJECTIVE: To investigate carotid atherosclerosis in individuals with masked hypertension (MHT) and white-coat hypertension (WCHT) in a general population. METHODS: Self-measurement of blood pressure at home (HBP) and casual blood pressure (CBP) measurements were recorded in 812 individuals aged at least 55 years (mean 66.4 years) from the general Japanese population. The intima-media thickness (IMT) of the near and far wall of both common carotid arteries was measured and averaged. The relationships between carotid atherosclerosis (IMT and plaque) and the four blood pressure groups (sustained normal blood pressure: HBP < 135/85 mmHg, CBP < 140/90 mmHg; WCHT: HBP < 135/85 mmHg, CBP >or= 140/90 mmHg; MHT: HBP >or= 135/85 mmHg, CBP < 140/90 mmHg; sustained hypertension: HBP >or= 135/85 mmHg, CBP >or= 140/90 mmHg) were examined using multivariate analysis adjusted for possible confounding factors. RESULTS: Adjusted IMT in individuals with sustained hypertension [0.77 mm; 95% confidence interval (CI) 0.75 to 0.79 mm] and MHT (0.77 mm; 95% CI 0.73 to 0.80 mm) was significantly greater than in those with sustained normal blood pressure (0.71 mm; 95% CI 0.69 to 0.72 mm) and WCHT (0.72 mm; 95% CI 0.71 to 0.74 mm) (P < 0.0001). The odds ratios for the presence of plaques in all four groups were similar to the trends in IMT. CONCLUSIONS: Our findings imply that CBP measurements alone are insufficient to distinguish individuals at high risk of carotid atherosclerosis from those at low risk. However, these individuals do have distinct HBP measurements, suggesting that HBP measurement could become a valuable tool for predicting carotid atherosclerosis.