Artificial sweetener sucralose in U.S. drinking water systems

The artificial sweetener sucralose has recently been shown to be a widespread of contaminant of wastewater, surface water, and groundwater. In order to understand its occurrence in drinking water systems, water samples from 19 United States (U.S.) drinking water treatment plants (DWTPs) serving more than 28 million people were analyzed for sucralose using liquid chromatography tandem mass spectrometry (LC-MS/MS). Sucralose was found to be present in source water of 15 out of 19 DWTPs (47-2900 ng/L), finished water of 13 out of 17 DWTPs (49-2400 ng/L) and distribution system water of 8 out of the 12 DWTPs (48-2400 ng/L) tested. Sucralose was only found to be present in source waters with known wastewater influence and/or recreational usage, and displayed low removal (12% average) in the DWTPs where finished water was sampled. Further, in the subset of DWTPs with distribution system water sampled, the compound was found to persist regardless of the presence of residual chlorine or chloramines. In order to understand intra-DWTP consistency, sucralose was monitored at one drinking water treatment plant over an 11 month period from March 2010 through January 2011, and averaged 440 ng/L in the source water and 350 ng/L in the finished water. The results of this study confirm that sucralose will function well as an indicator compound for anthropogenic influence on source, finished drinking and distribution system (i.e., tap) water, as well as an indicator compound for the presence of other recalcitrant compounds in finished drinking water in the U.S.     

Screening analysis of human pharmaceutical compounds in U.S. surface waters

The PhATE (Pharmaceutical Assessment and Transport Evaluation) model presented in this paper was developed as a tool to estimate concentrations of active pharmaceutical ingredients (APIs) in U.S. surface waters that result from patient use (or consumption) of medicines. PhATE uses a mass balance approach to model predicted environmental concentrations (PECs) in 11 watersheds selected to be representative of most hydrologic regions of the United States. The model divides rivers into discrete segments. It estimates the mass of API that enters a segment from upstream or from publicly owned treatment works (POTW) and is subsequently lost from the segment via in-stream loss mechanisms or flow diversions (i.e., man-made withdrawals). POTW discharge loads are estimated based on the population served, the API use per capita, the potential loss of the compound associated with human use (e.g., metabolism), and the portion of the API mass removed in the POTW. Simulations using three surrogate compounds showthat PECs generated by PhATE are generally within an order of magnitude of measured concentrations and that the cumulative probability distribution of PECs for all watersheds included in PhATE is consistent with the nationwide distribution of measured concentrations of the surrogate compounds. Model simulations for 11 APIs yielded four categories of results. (1) PECs fit measured data for two compounds. (2) PECs are below analytical method detection limits and thus are consistent with measured data for three compounds. (3) PECs are higher than (i.e., not consistent with) measured data for three compounds. However, this may be the consequence of as yet unidentified depletion mechanisms. (4) PECs are several orders of magnitude below some measured data but consistentwith most measured data forthree compounds. For the fourth category, closer examination of sampling locations suggests that the field-measured concentrations for these compounds do not accurately reflect human use. Overall, these results demonstrate that PhATE may be used to predict screening-level concentrations of APIs and related compounds in the environment as well as to evaluate the suitability of existing fate information for an API.     

Occurrence and removal of estrogenic short-chain ethoxy nonylphenolic compounds and their halogenated derivatives during drinking water production

The elimination of nonylphenol (NP), nonylphenol mono- and diethoxylates (NP1EO and NP2EO), nonylphenol carboxylates (NP1EC and NP2EC) and their brominated and chlorinated derivatives during drinking water treatment process in Sant Joan Despf waterworks in Barcelona was investigated utilizing a recently developed, highly sensitive LC-MS-MS method. The concentration of these potentially estrogenic compounds in raw water entering waterworks (taken from the Llobregat River, NE Spain) ranged from 8.3 to 22 microg/L, with NP2EC being the most abundant compound. Prechlorination reduced the concentration of short-chain ethoxy NPECs and NPEOs by about 25-35% and of NP by almost 90%. However, this reduction of concentrations was partially due to their transformation to halogenated derivatives. After prechlorination, halogenated nonylphenolic compounds represented approximately 13% of the total metabolite pool, of which 97% were in the form of brominated acidic metabolites. The efficiency of further treatment steps to eliminate nonylphenolic compounds (calculated for the sum of all short-chain ethoxy metabolites including halogenated derivatives) was as follows: settling and flocculation followed by rapid sand filtration (7%), ozonation (87%), GAC filtration (73%), and final disinfection with chlorine (43%), resulting in overall elimination ranging from 96 to 99% (mean 98% for four sampling dates). A few of the nonylphenolic compounds (NP, NP1EC, and NP2EC) were also identified in drinking water; however, the residues detected were generally below 100 ng/L, with one exception for NP2EC in November 2001 when a concentration of 215 ng/L was detected.     

Occurrence of fumonisins and moniliformin in corn and corn-based food products of U.S. origin

Food-grade corn and corn-based food products intended for human consumption were analyzed for the incidence and levels of fumonisin B1 (FB1), fumonisin B2 (FB2), moniliformin, and Fusarium molds. A total of 100 food-grade commercial corn samples were obtained from two corn processing companies at five different locations in the United States. Seventy-one percent of the samples contained FB1 with concentrations ranging from 43 to 1,642 microg/kg. None of the samples contained FB2. Fifty percent of the samples contained moniliformin with concentrations ranging from 26 to 774 microg/kg. All samples were infected by Fusarium molds, and the infection rates ranged from 8 to 88%. Thirty-four samples of corn-based food products were purchased from supermarkets in Arizona, California, Nebraska, and Ohio. Sixty-five percent of the samples contained FB1, ranging in concentrations from 28 to 2,679 microg/kg. FB2 was detected in 29% of the samples with concentrations ranging from 30 to 797 microg/kg. Sixty-eight percent of the samples contained moniliformin with concentrations ranging from 31 to 858 microg/kg. Sixty-two percent of the samples contained viable Fusarium mold propagules ranging from 9.5 x 10(1) to 5.5 x 10(5)/g. The simultaneous occurrence of FB1 and moniliformin was observed in 34% of corn samples and 53% of corn-based food products. This study has shown co-occurrence of fumonisins and moniliformin in food-grade corn and corn-based foods that indicates a risk of simultaneous exposure of consumers to both toxins.     

Occurrence and potential sources of pyrethroid insecticides in stream sediments from seven U.S. metropolitan areas

A nationally consistent approach was used to assess the occurrence and potential sources of pyrethroid insecticides in stream bed sediments from seven metropolitan areas across the United States. One or more pyrethroids were detected in almost half of the samples, with bifenthrin detected the most frequently (41%) and in each metropolitan area. Cyhalothrin, cypermethrin, permethrin, and resmethrin were detected much less frequently. Pyrethroid concentrations and Hyalella azteca mortality in 28-d tests were lower than in most urban stream studies. Log-transformed total pyrethroid toxic units (TUs) were significantly correlated with survival and bifenthrin was likely responsible for the majority of the observed toxicity. Sampling sites spanned a wide range of urbanization and log-transformed total pyrethroid concentrations were significantly correlated with urban land use. Dallas/Fort Worth had the highest pyrethroid detection frequency (89%), the greatest number of pyrethroids (4), and some of the highest concentrations. Salt Lake City had a similar percentage of detections but only bifenthrin was detected and at lower concentrations. The variation in pyrethroid concentrations among metropolitan areas suggests regional differences in pyrethroid use and transport processes. This study shows that pyrethroids commonly occur in urban stream sediments and may be contributing to sediment toxicity across the country.     

卷土重来的美国纺织投资热

新年伊始,日本东丽株式会社宣布,将向美国南卡州投资10亿美元,开发新型碳纤维材料.截至今日,成百亿上千亿的资金引发了美国纺织投资热.美国纺织权威比尔＆#183;史密斯先生深感诧异.他说,美国固然是世界上最大的纺织品贸易市场,又何以引发大量亚洲公司蜂拥而入？     

Occurrence of galactosyl isomaltol and galactosyl beta-pyranone in commercial drinking milk.

Occurrence of galactosyl isomaltol (GAI) and galactosyl beta-pyranone (GAP), two advanced glycosylation end products arising from the Maillard reaction of lactose via 1-deoxyosone pathway, was studied in commercial drinking milk. Galactosyl isomaltol was extracted from milk spiked with this isomaltol glycoside avoiding usage of any deproteinizing agent and was determined by a sensitive and interference-free HPLC method. No quantifiable amount of GAI proved to be present in any type of drinking milk, suggesting that some data reported in literature arise from uncontrolled conversion of GAP into GAI. The standard molecule of GAP was produced by heating a model system containing lysine and [U-14C]lactose, purified by solid phase extraction (SPE) on a C18 cartridge eluting with water, separated by the inverse distance function (IDF) standard HPLC method specified for lactulose determination, and characterized by both spectroscopic data and tandem mass spectrometry. The behaviour of formation of GAP and GAI in model systems containing lysine and lactose, heated under conditions of in bottle sterilization of milk, was studied in a wide range of values of the molar ratio lysine to lactose. While GAP easily forms as soon as lysine is present in the system, GAI does not form below a value of 0.1 of this molar ratio, so explaining why this compound is not present in commercial drinking milk. Amounts of GAP varying from 0.04 to 43.1 mumol/l were found in the different types of drinking milk ranging from high temperature pasteurized to in bottle sterilized, proving that this compound is a stable and sensible marker for evaluating the extent of the advanced Maillard reaction, hence the heating severity of commercial drinking milk. Moreover, GAP can be determined after conversion into GAI under acid warm conditions with a yield of 0.5 mol GAI from 1 mol GAP. Values of GAP obtained on commercial milk samples either by the direct HPLC method or after conversion into GAI were rather comparable, but the latter method needs further study in view of routine application.     

蜜汁山药

随着媒体与政府将关注点集中摆在肥胖症与健康议题上,某些人认为糖果工厂所蒙上的阴影更胜于巧克力工厂.但是美国人并不能、也并不会就此将糖果隔绝于生活之外.     

美国大豆食品

大豆是一种重要的农产品，近年来，其产量在美国和全世界都稳定增长。它具有很高的营养价值，其蛋白质和脂肪的含量很高，而且质量也很好。大豆还含有许多微量成分，其健康价值也是独一无二的。总体上讲，美国市场上的大豆食品可分为六个主要部分：豆油、传统大豆食品、大豆蛋白制品中，新一代大豆食品、大豆强化食品和功能性大豆成分。由于意识到了大豆食品的市场潜力，越来越多的大豆食品生产厂家和大豆的相关产品出现了，大豆食品有望成为21世纪世界上最普遍流行的食品。     

美国的食品包装法规

<正> 食品与包装的卫生及安全性,历来备受世界各国重视。美国对食品与包装的立法管理甚为严密,本文将剖析其食品与包装法规体系,综述美国FDA和美国农业部等有关食品包装法规的制订和操作执行情况。