气相色谱法同时测定水中12种挥发性消毒副产物

建立液-液萃取气相色谱法电子捕获检测器(GC/ECD)同时测定饮用水中12种挥发性消毒副产物(Disinfection byproducts, DBPs)的方法.采用过程标准校正降低预处理过程中引入的误差,方法检出限为0.08~0.21 μg/L, 全部组分在21.50 min内测定完成.不同浓度的DBPs在自来水和地表水中的回收率为80.9%~115.7%,相对标准偏差在0.9%~9.9%之间.各组分在0.5~200 μg/L浓度范围内线性关系良好,相关系数R>0.99.应用本方法测定了饮用水和地表水及其氯化后样品中DBPs的含量.本方法简便、快速、稳定,满足饮用水中挥发性DBPs的检测要求.     

Rapid Screening of Haloacetonitriles in Water Samples by Optimized Vortex‐assisted Liquid–Liquid Microextraction

This paper describes an optimized method for the quick screening of low levels of haloacetonitriles (HANs), a nitrogenous disinfection byproduct. The method is especially geared toward screening of water used for drinking and in swimming pools. The method is based on vortex‐assisted liquid–liquid microextraction (VALLME), which is carried out before determination of the gathered samples by gas chromatography‐mass spectrometry (GC‐MS). Factors that can potentially affect the extraction efficiency of the desired trace chemicals from the gathered sample were enhanced using the Box–Behnken design method. The optimal VALLME parameters for a 10‐mL water sample (pH 4, containing 3 g of sodium sulfate), according to the Box–Behnken design method, are extractant 160 μL dichloromethane and vortex extraction time of 1 min at the maximum speed (2500 rpm). The limits of quantitation calculated were 16–35 ng/L. Precision for both intra‐ and inter‐day analysis was also calculated, which was less than 11% on three concentration levels. Mean extraction recovery, otherwise known as trueness, was between 71 and 92%. The developed method was applied successfully to extract HANs from drinking and swimming pool water samples.     

Combination of ozone and ultrasonic-assisted aerosolization sanitizer as a sanitizing process to disinfect fresh-cut lettuce

Reduction of sanitizer dosage and development of non-immersion disinfection methods have become major focuses of research. Here, we examined the disinfection efficacy of combining gaseous ozone (4 and 8 ppm) with aerosolized oxidizing sanitizer [sodium hypochlorite (SH, 100 and 200 ppm)] and aerosolized organic acid [acetic acid (AA, 1% and 2%) and lactic acid (LA, 1% and 2%)]. Notably, 1% AA and 4 ppm gaseous ozone were ineffective for disinfecting Salmonella Typhimurium, and treatment with 1% AA + 8 ppm ozone caused browning of lettuce leaves and stimulated increases in aerobic mesophilic count (AMC), aerobic psychrotrophic count (APC), S. Typhimurium, and Escherichia coli O157:H7. Treatment with 2% LA + 8 ppm ozone resulted in the lowest S. Typhimurium, E. coli O157:H7, Listeria monocytogenes, AMC, APC, and molds and yeasts during storage (0–7 days at 4 °C). Quality analysis indicates that LA + 8 ppm ozone and SH + 8 ppm ozone did not negatively affect L*, a*, b*, polyphenolic content, weight loss, and sensory properties; however, the levels of two individual phenolic compounds (3,4-dihydroxybenzoic acid and vanillin), responsible for phenylpropanoid synthesis, were significantly increased after treatment with 2% LA + 8 ppm ozone. These findings provided insights into the use of LA combined with gaseous ozone for application in disinfecting fresh produce.     

离子色谱法同时测定饮用水中5种消毒剂副产物

建立了离子色谱电导检测大体积进样同时测定饮用水中5种消毒剂副产物(亚氯酸盐、溴酸盐、氯酸盐、二氯乙酸和三氯乙酸)的方法.选用大容量IonPac AS19阴离子交换分析柱,以KOH溶液梯度淋洗,流速为1.0 mL/min,可在33 min内一次进样同时分析上述5种消毒剂副产物和7种常见阴离子.亚氯酸盐、溴酸盐、氯酸盐、二氯乙酸和三氯乙酸的检出限分别为0.43、0.68、0.78、1.04和1.53μg/L(500 μL进样),线性相关系数r＞0.9995.运用该法测定了自来水中5种消毒剂副产物,并对样品加标回收,回收率在97.6%～105.6%之间.对影响分离和测定的因素,如温度、共存非测定离子、相邻离子间等进行了研究.     

Applicability of an In-Vitro Digestion Model to Assess the Bioaccessibility of Phenolic Compounds from Olive-Related Products

The Mediterranean diet includes virgin olive oil (VOO) as the main fat and olives as snacks. In addition to providing nutritional and organoleptic properties, VOO and the fruits (olives) contain an extensive number of bioactive compounds, mainly phenolic compounds, which are considered to be powerful antioxidants. Furthermore, olive byproducts, such as olive leaves, olive pomace, and olive mill wastewater, considered also as rich sources of phenolic compounds, are now valorized due to being mainly applied in the pharmaceutical and nutraceutical industries. The digestive system must physically and chemically break down these ingested olive-related products to release their phenolic compounds, which will be further metabolized to be used by the human organism. The first purpose of this review is to provide an overview of the current status of in-vitro static digestion models for olive-related products. In this sense, the in-vitro gastrointestinal digestion methods are widely used with the following aims: (i) to study how phenolic compounds are released from their matrices and to identify structural changes of phenolic compounds after the digestion of olive fruits and oils and (ii) to support the functional value of olive leaves and byproducts generated in the olive industry by assessing their health properties before and after the gastrointestinal process. The second purpose of this review is to survey and discuss all the results available to date.     

Cold Atmospheric Plasma Jet as a Possible Adjuvant Therapy for Periodontal Disease

Due to the limitations of traditional periodontal therapies, and reported cold atmospheric plasma anti-inflammatory/antimicrobial activities, plasma could be an adjuvant therapy to periodontitis. Porphyromonas gingivalis was grown in blood agar. Standardized suspensions were plated on blood agar and plasma-treated for planktonic growth. For biofilm, dual-species Streptococcus gordonii + P. gingivalis biofilm grew for 48 h and then was plasma-treated. XTT assay and CFU counting were performed. Cytotoxicity was accessed immediately or after 24 h. Plasma was applied for 1, 3, 5 or 7 min. In vivo: Thirty C57BI/6 mice were subject to experimental periodontitis for 11 days. Immediately after ligature removal, animals were plasma-treated for 5 min once—Group P1 (n = 10); twice (Day 11 and 13)—Group P2 (n = 10); or not treated—Group S (n = 10). Mice were euthanized on day 15. Histological and microtomography analyses were performed. Significance level was 5%. Halo diameter increased proportionally to time of exposure contrary to CFU/mL counting. Mean/SD of fibroblasts viability did not vary among the groups. Plasma was able to inhibit P. gingivalis in planktonic culture and biofilm in a cell-safe manner. Moreover, plasma treatment in vivo, for 5 min, tends to improve periodontal tissue recovery, proportionally to the number of plasma applications.     

饮用水消毒副产物及其分析技术

介绍了饮用水中液氯、臭氧、二氧化氯消毒副产物的特性和现状,总结了近年来消毒副产物分析领域中常用的各种样品前处理技术及检测方法,展望了今后研究的发展方向.     

Influence of Hydrogen Peroxide on Disinfection and Soil Removal during Low-Temperature Household Laundry

In the Water, Energy and Waste Directive, the European Commission provides for the use of household washing programmes with lower temperatures (30–40 °C) and lower water consumption. However, low washing temperatures and the absence of oxidising agents in the liquid detergents, and their reduced content in powder detergents, allow biofilm formation in washing machines and the development of an unpleasant odour, while the washed laundry can become a carrier of pathogenic bacteria, posing a risk to human health. The aim of the study was to determine whether the addition of hydrogen peroxide (HP) to liquid detergents in low-temperature household washing allows disinfection of the laundry without affecting the properties of the washed textiles even after several consecutive washes. Fabrics of different colours and of different raw material compositions were repeatedly washed in a household washing machine using a liquid detergent with the addition of 3% stabilised HP solution in the main wash, prewash or rinse. The results of the antimicrobial activity, soil removal activity, colour change and tensile strength confirmed the excellent disinfection activity of the 3% HP, but only if added in the main wash. Its presence did not discolour nor affect the tensile strength of the laundry, thus maintaining its overall appearance.     

LC and NMR Studies for Identification and Characterization of Degradation Byproducts of Olmesartan Acid,Elucidation of Their Degradation Pathway and Ecotoxicity Assessment

The discovery of various sartans, which are among the most used antihypertensive drugs in the world, is increasingly frequent not only in wastewater but also in surface water and, in some cases, even in drinking or groundwater. In this paper, the degradation pathway of olmesartan acid, one of the most used sartans, was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants. The structures of nine isolated degradation byproducts (DPs), eight of which were isolated for the first time, were separated via chromatography column and HPLC methods, identified by combining nuclear magnetic resonance and mass spectrometry, and justified by a proposed mechanism of formation beginning from the parent drug. Ecotoxicity tests on olmesartan acid and its nine DPs showed that 50% of the investigated byproducts inhibited the target species Aliivibrio fischeri and Raphidocelis subcapitata, causing functional decreases of 18% and 53%, respectively.     

Simultaneous determination of three chloroacetic acids,three herbicides,and 12 anions in water by ion chromatography

An ion chromatography method was developed for the simultaneous detection of three soluble herbicides (glyphosate, bentazone and picloram), three chlorine disinfection byproducts (monochloroacetic acid, dichloroacetic acid and trichloroacetic acid) and 12 anions in water (Cl^–, Br^–, SO₄^2–, CO₃^2–, ClO₃^–, ClO₄^–, BrO₃^–, PO₄^3–, NO₂^–, NO₃^–, CH₃COO^– and COO^–). High linearity (r² > 0.996) was observed for all target analytes for each respective concentration range. The limit of detection and limit of quantitation were between 0.21–0.85 and 0.06–25.46 μg/L, respectively. However, the interference effect of Cl^–, NO₃^–, SO₄^2– and CO₃^2– on some target analytes must be considered during the analysis. Sample pre‐treatment by a hydrogen column (H‐column) required to reduce the negative effect of CO₃^2–. Additionally, sample pre‐treatment by a sliver–hydrogen column (Ag–H‐column) is required when Cl^– > 100 mg/L and SO₄^2– < 50 mg/L, and pre‐treatment by both a barium column (Ba‐column) and an H‐column is required when Cl^– > 100 mg/L and SO₄^2– > 50 mg/L. When Cl^– > 100 mg/L, SO₄^2– > 50 mg/L and CO₃^2– > 20 mg/L, the sample pre‐treatment by either an Ag–H–Ba‐column or an Ag–H‐column and Ba‐column is required to minimize interference.