微波萃取-GC／MS法分析测定塑料中多环芳烃

建立了塑料中16种美国环境保护局（EPA）优先监控的多环芳烃的气相色谱-质谱（GC／MC）联用分析方法。样品经微波萃取后,再经硅胶柱净化,用GC／MS分离测定。优化了16种多环芳烃（PAHs）的分离测定条件．结果16种PAHs的平均回收率为64．2％-95．6％,精密度实验RSD为0．8％-6．2％,检测限（S／N为3）为0．001～0．01mg／kg。该方法灵敏度高、准确性好,完全可以满足塑料多环芳烃的检测要求。     

气相色谱－质谱法测定环保橡胶油中的多环芳烃

建立了环保橡胶油中多环芳烃的气相色谱／质谱（GC／MS）测定方法。样品经环已烷－二甲基亚砜两次萃取,硅胶固相萃取柱净化后,用GC／MS分离测定。优化了8种多环芳烃（PAHs）化合物的分离测定条件。结果8种PAHs回收率范围为62％－94％,日内（11=5）相对标准偏差为3．72％～6．91％。方法具有灵敏度高、准确度好、能同时分离测定8种多环芳烃化合物的优点,适合于芳烃油中多环芳烃化合物的测定。     

C_(18)膜萃取—气相色谱/质谱法测定海螺沟冰雪中多环芳烃

优化了C18固相膜萃取条件,建立了C18膜萃取-气相色谱/质谱联用测定海螺沟冰雪中16种多环芳烃的分析方法。结果表明,C18圆盘萃取减少了提取时间、提高了萃取效率、节省了试剂,还可以加大取样量。采用GC/MS的选择离子检测方式对分别加有高、中、低三种浓度混标的3 L纯水中PAHs进行定性定量分析,测得相对标准偏差小于15.83%,平均回收率分别为75.98%~99.30%、79.50%~91.60%和76.31%~89.78%,方法检出限为0.001 0~0.010 7μg/L。将本方法应用于海螺沟雪水的检测,结果满足其冰雪中多环芳烃的分析要求。     

HPLC法测定橡胶填充油中稠环芳烃含量的研究

建立了橡胶填充油中16种优控多环芳烃(PAHs)的高效液相色谱(二极管阵列检测器HPLC)测定方法,探讨了样品的提取、固相萃取净化等前处理方法,同时也对HPLC的仪器测定条件进行了优化.在优化的条件下,16种多环芳烃化合物的平均回收率为60.4%～109.8%.方法的检测限0.49～4.32μg/L.结果表明,在检测橡...     

气相色谱-质谱联用测定橡胶制品中的多环芳烃

采用气相色谱-质谱联用方法测定橡胶制品中的多环芳烃(PAHs)含量.确定试验条件为:萃取溶剂正己烷,超声波提取时间 25 min,正己烷/乙酸乙醇混合溶剂用量(样品量为1.0 g) 5 mL;可对16种受控PAHs进行分离,定量分析回收率为88.6%～108.8%,检测限为0.38～3.56 μg·kg-1,标准偏差为2.18%-8.20%.     

金属皂中多环芳烃的高效液相色谱法测定

建立了一种测定金属皂中多环芳烃的高效液相色谱方法,该方法使用的色谱柱为多聚C18(LC-PAH)柱,流动相为乙腈/水,采用梯度淋洗方式。该方法线性范围广,平均回收率为75.29%~99.89%,精密度实验RSD为1.75%~6.85%,检测限(S/N=5)为0.05~0.20 mg/L,满足了金属皂中多环芳烃的检测要求。     

神木原煤萃取产物中多环芳烃含量的研究

对神术原煤分别用苯及石油醚作萃取溶剂进行索式萃取,采用硅胶柱层析纯化,利用气相色谱/质谱联用仪（GC／MS）分别对上述萃取液的硅胶层析产物进行了解折,并对其中的9种多环芳烃（PAHs）进行了定量测定;研究了不同萃取剂所得萃取液中多环芳烃的分布。结果表明,神木原煤中的PAHs以两环、三环和四环PAHs为主,苯萃取液与石油醚苹取液中PAHs的分布大体相同,但在丰度上有很大差别。     

负载多壁碳纳米管SPME涂层制备及其性能

结合多壁碳纳米管优异的吸附性能,采用溶胶-凝胶法制备了负载多壁碳纳米管的固相微萃取(SPME)涂层,对16种多环芳烃(PAHs)标准化合物进行了萃取实验。结果表明:所制备的负载多壁碳纳米管的SPME涂层萃取性能优于商用PDMS涂层,特别是能有效提高对多环芳烃的萃取性能;对16种PAHs的检出限在0.21～9.86μg/L;除苯并(b)荧蒽外,在0～2500μg/L线性范围内,线性关系良好,相关系数均在0.9502～0.9999;5次平行样测定的相对标准偏差2.9%～14.3%。将该涂层应用于煤矿矿区地下水中多环芳烃类物质的检测,成功检测出了菲、蒽、荧蒽、芘、苣、苯并(a)芘等物质。     

土壤中多环芳烃预处理及分析方法研究

综述了土壤PAHs的预处理和测定分析方法。预处理方法主要介绍了索氏提取、超声波萃取、超临界流体萃取、加速溶剂萃取和协同萃取等。检测方法具体介绍了高效液相色谱法(HPLC)法、恒能量同步荧光法(CESF)、气相色谱-质谱(GC/MS)法等。重点分析比较了提取和纯化过程,为今后研究土壤中的多环芳烃提供一定的技术参考。     

QuEChERS前处理-GC-MS法测定土壤中16种多环芳烃

建立了Qu ECh ERS前处理-气相色谱-质谱联用技术分析土壤中16种多环芳烃(PAHs)的新方法。优化的前处理方法:乙腈饱和的正已烷混合溶液作提取剂超声提取,使用分散固相萃取净化离心管(含400 mg PSA(乙二胺-N丙基硅烷)、400 mg C18EC、1200 mg硫酸镁)净化去除杂质。色谱条件:使用HP-5MS色谱柱,在45 min内16种PAHs分离良好。使用提取特征离子检测并确证,有效消除了土壤基质干扰,避免假阳性结果。16种PAHs在10~1000 ng/m L浓度范围内具有良好的线性关系,相关系数均大于0.995,平均加标回收率为71.2%~119.2%,相对标准偏差为6.1%~18%,检出限为0.10~0.92 ng/g。此法适宜应用于土壤中16种PAHs的检测。     

越南安息香种子脂肪酸的在线甲基化-GC分析研究

建立了分析越南安息香种子油、果实和果壳的脂肪酸组成的在线甲基化-气相色谱法。将微克级的安息香样品与2μL衍生化试剂三甲基氢氧化硫（0.2 mol/L）加入裂解器,在350℃下瞬间反应,由气相色谱在线检测到8种脂肪酸甲酯成分,主要有棕榈酸（ C16∶0）、硬脂酸（ C18∶0）、油酸（ C18∶1）、亚油酸（ C18∶2）和亚麻酸（ C18∶3）,不饱和脂肪酸含量在84.5%以上,其中亚油酸含量最高,达47.29%。5次平行测定的相对标准偏差（ RSD）小于3.81%。并结合相似性分析法比较了4种不同产地的安息香种仁与6种食用油的脂肪酸组成,相似性结果表明不同产地的安息香种仁的脂肪酸组成相似,其脂肪酸组成与食用植物油相近,与玉米油的组成分布最为接近,相似系数在0.987~0.990,且越南安息香种子中人体必需的多不饱和脂肪酸含量（ C18∶2和C18∶3）与大豆油和葵花籽油相近,高于一般植物油,具有较高的营养价值。结果表明该法简便、快速、准确,适合越南安息香种子油脂的测定。     

The effect of lyophilization on the solvent extraction of lipid classes,fatty acids and sterols from the oysterCrassostrea gigas

The lipid class compositions of adult Pacific oysters [Crassostrea gigas (Thunberg)] were examined using latroscan thin-layer chromatography/flame-ionization detection (TLC/FID), and fatty acid compositions determined by capillary gas chromatography and gas chromatography/mass spectrometry (GC/MS). The fatty acid methyl esters were separated using argentation TLC and also analyzed as their 4,4-dimethyloxazoline derivatives using GC/MS. Major esterified fatty acids inC. gigas were 16∶0, 20∶5n−3, and 22∶6n−3. C₂₀ and C₂₂ nonmethylene interrupted (NMI) fatty acids comprised 4.5 to 5.9% of the total fatty acids. The NMI trienoic fatty acid 22∶3(7,13,16) was also identified. Very little difference was found in the proportions of the various lipid classes, fatty acids or sterols between samples of adult oysters of two different sizes. However, significant differences in some of the lipid components were evident according to the method of sample preparation used prior to lipid extraction with solvents. Lyophilization (freeze drying) of samples led to a significant reduction in the amounts of triacylglycerols (TG) extracted by solvents in two separate experiments (7.0 and 52.5% extracted). Extracts from lyophilized samples had less 16∶0, C₁₈ unsaturated fatty acids, and 24-ethylcholest-5-en-3β-ol, while C₂₀ and C₂₂ unsaturated fatty acids comprised a higher proportion of the total fatty acids. There was no significant change in the amounts of polar lipids, total sterols, free fatty acids or hydrocarbons observed in extracts from lyophilized samples relative to extracts from nonlyophilized samples. Addition of water to the freezedried samples prior to lipid extraction greatly improved lipid yields and resulted in most of the TG being extracted.     

THE LOADS OF PAHS IN WASTEWATER AND SEWAGE SLUDGE OF MUNICIPAL TREATMENT PLANT

Abstract

Sewage and sewage sludge from a municipal wastewater treatment plant were analyzed for 16 EPA-PAHs. This plant is a classic mechanical-biological treatment plant, consisting of activated sludge technology with additional chemical treatment for the removal of phosphorus compounds. The process of sewage sludge treatment is carried out in closed as well as open sludge digesters. Primary and mechanically thickened sludge are passed through the fermentation process. Digested sludge is dewatered on filter-press through addition of flocculent. The measurements were obtained to investigate the effect of different treatment stages on PAH content in wastewater and sewage sludge. The following wastewater samples were collected: crude ones and those after sand trap, primary sedimentation, biological treatment and secondary sedimentation. Sewage sludge samples were collected from: primary sludge, digested sludge and dewatered sludge. PAH load in influent, mechanically and biologically treated sewage, as well as in raw digested and dewatered sludge, were calculated. PAHs were extracted from wastewater and sludge samples, with cyclohexane, dichloromethane using an ultrasonic method. Gas chromatograph equipped with mass spectrometry was used for qualitative and quantitative determination of PAHs. Mechanical and biological treatment proved the removal of 83–85% of PAHs from the influent. Despite this its daily PAH load introduced into the environment was high and reached 27–37% of PAH load in influent. In sewage sludge it was 46–70 g/d of PAHs (carcinogenic PAHs content 4–12%). In waste sludge (filter pressed sludge and sand from detrirer) PAH total load reached 42–68 g/d with (10–17% of carcinogenic PAHs).     

Comparison of fatty acid content of imported peanuts

Variability in fatty acid compositions of peanuts imported from six different countries into the United States were studied to determine their effect on processing and storage conditions. The oil content ranged from 44.1 to 50.4%. Major fatty acids, palmitic acid (C16:0), oleic acid (C18:l), and linoleic acid (C18:2) ranged from 8.6 to 12.7, 35.9 to 61.1 and 21.7 to 44.2%, respectively. Oleic and lino-leic acids together comprised ca. 78.0–83.0% of the total fatty acids. Highly significant differences (P<.01) in fatty acid compositions were obtained between samples and between locations (countries of origin). Indicators of stability of the peanut samples as measured by the oleic/linoleic acid ratio (O/L) and iodine value (IV) of the extracted peanut oils showed variable but significant differences (P <.05) between locations. Generally, higher O/L ratios corresponding to lower IV indicate better stability and longer shelf-life of the samples.     

Extraction of Nitraria tangutorum seed lipid using different extraction methods and analysis of its fatty acids by HPLC fluorescence detection and on‐line MS identification

The seed lipid of Nitraria tangutorum was extracted by supercritical carbon dioxide extraction, microwave‐assisted reflux extraction, ultrasound‐assisted extraction, or solvent reflux extraction. The experimental parameters of supercritical carbon dioxide extraction including pressure, temperature, particle size, and extraction time were investigated. A facile and sensitive method for the simultaneous determination of 30 saturated and 9 unsaturated fatty acids by HPLC with fluorescence detection after pre‐column derivatization was developed. Fatty acid derivatives were separated on a reversed‐phase Eclipse XDB‐C₈ column in conjunction with gradient elution. Identification of fatty acid derivatives was carried out by on‐line APCI/MS in positive‐ion mode. Excellent quantitative linear responses of the 39 fatty acids were observed in the range of 0.014 to 14 μmol/L with correlation coefficients higher than 0.9992. Limits of detection were in the range of 0.32–3.7 nmol/L (S/N = 3). The fatty acids in Nitraria tangutorum seed lipid with or without saponification extracted by the four different methods were determined and compared. The results indicated that the mass percentage of unsaturated fatty acids (mainly oleic acid, linoleic acid and linolenic acid) in Nitraria tangutorum seed lipid was up to 79%, and the best method was supercritical carbon dioxide extraction.     

Semimicro determination of total fatty acids and unsaponifiable matter

A semimicro method for determining both total fatty acids and unsaponifiable matter in fats, fatty acids, and soap is presented. The procedure involves saponification and recovery of the total fatty acids (which includes the unsaponifiables), removal of the fatty acids with anion exchange resins, and determination of the unsaponifiable matter by weight. The total fatty acid method was evaluated on seven samples and showed a standard deviation from the mean of 0.21%. The unsaponifiable matter determination gives good reproducibility with a standard deviation from the mean of 0.06%. Since this ion exchange is a direct determination of the nonionic components, the results obtained from it should be more accurate and more nearly the true values than the macro extraction method which is empirical. Presented at the annual spring meeting, American Oil Chemists’ Society, Dallas, Tex., April 4–6, 1960.     

Rapid analysis of fatty acids in plasma lipids

A rapid and convenient procedure for the quantitative determination of the fatty acid composition of plasma lipids is described. Human plasma was applied directly to the preadsorbent zones of thin-layer silica gel plates with added antioxidant, internal standards and carriers. The thin-layer chromatography (TLC) plates were partially developed with methanol followed by chloroform/methanol (1∶1, v/v), and then they were fully developed in hexane/diethyl ether/acetic acid (80∶20∶1, v/v/v) to separate the major classes of lipids. Silica gel from regions containing the separated lipids was scraped into screw-capped tubes and treated with boron trifluoride-methanol prior to gas chromatography. The method of direct application to TLC plates gave yields and compositions of fatty acids very similar to the method of applying extracted plasma lipids. This relatively simple method is suitable for analyzing the fatty acids in plasma lipids from a 50 microliter finger-tip blood samples from an individual, and it may be useful in wide-scale screening of different individuals to estimate the relative amounts of ingested polyunsaturated fatty acids. Pfizer Biomedical Research Awardee.     

Synthesis of Thumba,Castor and Sal Fatty Ethanolamide-Based Anionic Surfactants

The study involved the preparation and evaluation of anionic surfactants from non-edible oil based thumba (containing unsaturated-rich fatty acids, 80.9 %), castor (containing ricinoleic acid, a hydroxy fatty acid 89.3 %) and sal (containing saturated-rich fatty acids, 56.5 %). The oils extracted from these seeds (using Soxhlet) were reacted with monoethanolamine and diethanolamine to get corresponding fatty mono- and diethanolamides. The ethanolamides were sulfated using chlorosulfonic acid and the sulfated sodium salts were evaluated for surfactant properties namely surface tension, critical micelle concentration (CMC), emulsifying property, wetting, foaming power and calcium tolerance. The properties were compared with sodium dodecyl sulfate (SDS) a well known anionic surfactant. Among the different sulfated sodium salts of ethanolamides, thumba showed superior surfactant properties compared to castor and sal. Sulfated sodium salt of thumba monoethanolamide showed better properties (CMC, 0.035 mmol/L, surface tension 30.2 mN/m and calcium tolerance >1,000 ml, 0.5 % calcium acetate solution) compared to sulfated sodium salts of thumba diethanolamides, followed by sulfated sodium salts of castor monoethanolamide (CMC 0.037 mmol/L, surface tension 35.3 mN/m and calcium tolerance >1,000 ml, 0.5 % calcium acetate solution). Sal being saturated rich was not properly soluble in water and showed poor surfactant properties compared to the other two. Also the sulfated sodium salts of thumba and castor ethanolamides exhibited superior properties compared to SDS.