A Rapid Determination of Ergosterol in Grains Using Gas Chromatography–Mass Spectrometry Method Without Derivatization

Food Analytical Methods - A simple, rapid and sensitive GC-MS method using on-column injection was developed and validated to determine ergosterol (ERG) levels in maize and wheat. In this method,...     

A study of a micro co‐generation system's conformation for residential use considering observed fluctuating characteristics of hot‐water demand

This paper discusses a conformation of a micro co‐generation system (µCGS) for residential use. The evaluation is based on the hot‐water demand observed in three families who live in the same apartment house. Assuming DSS operation of µCGS, we evaluated the required capacity of PEFC, hot‐water tank, and backup boiler to meet a series of daily hot‐water demand observed in three houses. The results are: (1) µCGS with 2‐kW PEFC and 350‐L hot‐water tank are required in family B when µCGS is not equipped with the backup boiler, (2) the additional 5 kW of the backup boiler reduces the required capacity of the hot‐water tank by 50 L, (3) the evaluation based on hourly averaged hot‐water demand patterns would underestimate the required capacity of the hot‐water tank, (4) the required capacity of the hot‐water tank could be reduced by the leveling effect of the hot‐water demand pattern along three families. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(2): 30–37, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10080     

Levels of dioxins in rice, wheat, soybean, and adzuki bean cultivated in 1999 to 2002 in Japan and estimation of their intake

A total of 369 samples of rice (n = 311), wheat (n = 10), soybean (n = 44), and adzuki bean (n = 4) collected from various locations in Japan between 1999 and 2002 were analyzed for PCDDs, PCDFs (PCDD/Fs) and coplanar PCBs. Sampling points within about 1 km of operational municipal waste incinerators that were considered sources of dioxins were defined as "near-source" areas, and all other sampling points were defined as "general" areas. The toxic equivalent quantity (TEQ) values of soybean samples collected from near-source areas were significantly higher (p < 0.05) than those from general areas. A significant difference of TEQs among sampling years in rice in general areas was also found. However, the differences could not be explained by the presence or absence of incineration plants in the area surrounding the sampling point or by a temporal decrease of air pollution. The TEQs of the crops varied widely, but the median value of each crop was quite low, at 0.000021, 0.00013, 0.0000095, and 0.00016 pg-TEQ/g wet wt. in rice, wheat, soybean and adzuki bean, respectively. On the basis of these survey results, the daily intake of PCDD/Fs and coplanar PCBs from rice, wheat, soybean, and adzuki bean was calculated. The daily intakes from these crops were estimated to be 0.0056 pg-TEQ/kg B.W./day on the assumption that "not detected" (ND) could be taken as zero, ND = 0, and 0.18 pg-TEQ/kg B.W./day if ND is put equal to 1/2 LOD (half the limit of detection). In comparison with the tolerable daily intake set in Japan for PCDD/Fs and coplanar PCBs (4 pg-TEQ/kg B.W./day), it was considered that the levels of contamination by PCDD/Fs and coplanar PCBs in these crops cultivated in the environment of Japan do not present a problem.     

Levels of dioxins in Japanese fruit in 1999 to 2002 and estimation of their intake

A total of 148 samples of nine species of fruit were collected between 1999 and 2002 and analyzed for PCDDs, PCDFs (PCDD/Fs) and Coplanar PCBs. Sampling points within about 1 km of operational municipal waste incinerators that were considered sources of dioxins were defined as "near-source" areas, and all other sampling points were defined as "general" areas. The TEQ of apples collected from near-source areas was significantly higher than that from general areas (p < 0.05). 3,3',4,4',5-PeCB (#126) was the main contributor to this difference in TEQs between apples collected from near-source areas and from general area. A principal component analysis performed to estimate the source of this congener revealed that not only the municipal waste incinerators, but also PCBs in the environment were associated with the high TEQ in apples collected from near-source areas. The daily intakes of PCDD/Fs and Coplanar PCBs from the fruits including skin were estimated to be 0.0082 pg-TEQ/kg b.w./day (ND = 0) and 0.072 pg-TEQ/ kg b.w./day (ND = 1/2 LOQ). Though these values are likely to be overestimates, they are far lower than the tolerable daily intake set in Japan for PCDD/Fs and Coplanar PCBs (4 pg-TEQ/kg b.w./day). It is thought that fruit intake is not an important pathway of human exposure to PCDD/Fs and Coplanar PCBs.