高分辨气相色谱/高分辨双聚焦磁式质谱联用定量检测市售牛奶中的二噁英和呋喃

采用高分辨气相色谱/高分辨双聚焦磁式质谱联用仪（HRGC/HRMS）定量检测了牛奶中17个4至8个氯原子取代的噁英和呋喃。样品中的二噁英经过液-液萃取、碳柱富集、色谱柱纯化、分离,以HRGC/HRMS-MID方法检测,用美国EPA1613方法进行严格的质量控制和同位素稀释的方法定量,该方法定量可精确到pg/g即ppt水平。结果表明,同位素标准物的回收率分布于58.46％～79.99％之间。1,2,3,7,8-PeCDF、1,2,3,4,7,8,9-HpCDF、2,3,7,8-TCDD均未检出,样品中17个同系物异构体以OCDF和OCDD的含量为最高,分别为0.065pg/g和 0.202pg/g,样品的总TEQ值为0.033pgTEQ/g。该方法定性、定量准确,为目前国际上权威认可的二噁英定量检测方法。     

高分辨气相色谱高分辨质谱测定鱼体中的类二(口恶)英多氯联苯

〔目的〕采用高分辨气相色谱 高分辨双聚焦磁式质谱联用仪 (HRGC HRMS)定量检测了鱼体中 12种类二口恶英多氯联苯 (PCBs)化合物。〔方法〕参照美国EPA1668A方法 ,采用索式抽提和自动纯化系统 (FMS)等仪器对鱼体样品中的类二口恶英PCBs进行纯化和富集、用同位素稀释气相色谱与高分辨质谱联用 -多离子检测方法检测。〔结果〕该方法可对PCBs同系物进行有效分离 ,同位素标准物的回收率分布于 44 .8%～ 93 .1%之间 ,CSL考核样的检测结果均在令人满意的范围之内 ,7种类二口恶英PCBs在鱼体中可检测出 ,总TEQ值为 0 .3 5pg g。〔结论〕该方法可以准确检测样品中类二口恶英PCBs ,所检鱼体中含有一定量类二口恶英PCBs ,有必要做更多样品 ,对其污染情况做出评价。     

HRGC／HRMS定量检测市售牛奶中二恶英和呋喃

目的：采用高分辨气相色谱／高分辨双聚焦碳式质谱联用仪（HRGC／HRMS）定量检测了牛奶中17个4－8个氯原子取代的二恶英和呋喃。方法：样品中的二恶英经过液－液萃取、碳柱富集、色谱柱纯化，分离，以HRGC／HRMS－MID方法检测，用美国EPA1613方法进行严格的质量控制和同位素稀释的方法定量，该方法定量可精确到pg/g即ppt水平。结果：该方法的检测限TCDF和TCDD分别为0．0222pg/μl和0．0317pg/μl，在17个PCDDs/PCDFs中，其检测限为最低，同位素标准物的回收率分布于58．46％－79．99％之间，1，2，3，7，8－PeCDF,1,2,3,4,7,8,9-HpCDF,2,3,7,8-TCDD均未检出，样品中17个同系物异构体以OCDF和OCDD的含量为最高，分别为0．065pg/g和0．202pg/g，样品的总TEQ值为0．033pgTEQ/g。结论：采用高分辨气相色谱／高分辨双聚焦磁式质谱联用仪和同位素稀释的方法对基质中的目标化合物二恶英进行检测，该法定性，定量准确，高灵敏度。     

某市市售牛奶及其制品中二[口][恶]英类化合物污染水平

目的了解某市市售牛奶及其制品中二[口][恶]英类化合物污染情况。方法于2007年2-6月采集某市市售液体牛奶和奶粉（各5份），用高分辨气相色谱-高分辨双聚焦磁式质谱联用仪（HRGC-HRMS）定量检测样品中的二[口][恶]英及多氯联苯水平。采用索式抽提装置、FMS自动纯化系统对市售液体牛奶及奶粉样品中的二[口][恶]英（PCDD／Fs）及多氯联苯（PCBs）组分进行纯化和富集，采用同位素稀释法，以HRGC／HRMS联用仪检测。结果奶粉和液体牛奶的总TEQ[∑（PCDD／Fs＋PCBs）]平均值分别是0.43pg／g脂肪和3.83pg／g脂肪，中位数分别是0.34pg／g脂肪和2.04pg／g脂防。所有奶样的总TEQ[∑（PCDD／Fs＋PCBs）]均值是2.13pg／g脂肪，中位数是0.815pg／g脂肪。本次调查的所有样品的平均总TEQ[∑（PCDD／Fs＋PCBs）]远低于欧盟所设定的奶品二[口][恶]英类化合物的限量标准。受试样品中除了两种液体牛奶样品二[口][恶]英类化合物总TEQ超过欧盟限量标准外，其他液体牛奶和奶粉样品二嗯[口][恶]英及多氯联苯含量远低于欧盟的限量标准。但足，液体牛奶的平均二[口][恶]英浓度明显高于奶粉样品，结论本次采集的市售牛奶及其制品存在二[口][恶]英类化合物的污染。     

高分辨质谱法测定海鱼中二噁(口英)和多氯联苯

目的采用同位素稀释的HRGC/HRMS法定量检测鱼体中17种2,3,7,8-氯取代的二噁(口英)(PCDD/Fs)和12种二噁(口英)多氯联苯(PCBs).方法参照美国EPA1613及EPA1668A方法,采用索式抽提和自动纯化系统(FMS)对鱼体中的PCDD/Fs及PCBs进行纯化和富集、用同位素稀释气相色谱与高分辨质谱联用-多离子检测方法检测.结果该方法可对样品中的PCDD/Fs及PCBs同系物进行有效分离,PCDD/Fs同位素标准物的回收率为83.83%～98.48%,PCBs同位素标准物的回收率为50.06%～90.56%.13种PCDD/Fs在鱼体中可检出,总毒性当量(TEQ)为0.86 pg/g,12种二噁(口英)PCBs在鱼体中均可检测出,总TEQ值为2.77pg/g.结论该方法可以同时对同一样品中的17种PCDD/Fs及12种二噁(口英)PCBs进行检测,检测效率高,结果准确可靠.     

高分辨气相色谱／高分辨双聚焦磁式质谱联用定量检测市售牛奶中的二恶英和呋喃

采用高分辨气相色谱／高分辨双聚焦磁式质谱联用仪（HRGC／HRMS）定量检测了牛奶中17个4至8个氯原子取代的二恶英和呋喃。样品中的二恶英经过液－液萃取、碳柱富集、色谱柱纯化、分离，以HRGC／HRMS－MID方法检测，用美国EPA1613方法进行严格的质量控制和同位素稀释的方法定量，该方法定量可精确到pg/g即ppt水平。结果表明，同位素标准物的回收率分布于58．46％－79．99％之间。1，2，3，7，8－PeCDF、1，2，3，4，7，8，9－HpCDF、2,3,7,8-TCDD均未检出，样品中172上同系物异构体以OCDF和OCDD的含量为最高，分别为0．065pg/g和0．202pg/g，样品的总TEQ值为0．033pg TEQ/g。该方法定性、定量准确，为目前国际上权威认可的二恶英定量检测方法。     

海水鱼体中的二(口恶)英类化合物分析

目的对海水鱼体内二(口恶)英检测方法的研究.方法参照美国EPA1613方法,采用索式抽提和自动纯化系统等仪器对鱼体中的二(口恶)英组分进行纯化和富集、用同位素稀释气相色谱与高分辨质谱联用-多离子检测方法检测.结果该方法的检测限为0.001 pg/g～0.176 pg/g,仪器检测限为6.5fg～157.9fg,同位素标准物的回收率分布于70.81%～87.33%之间,17种2,3,7,8-氯取代的二(口恶)英类化合物在鱼体中均可检测出,总TEQ值为1.117 pg/g.结论本实验室方法可以准确检测样品中二(口恶)英类化合物,所检鱼体中含有二(口恶)英化合物,有必要做更多样品,对其污染情况做出评价.     

陕西省动物源性食品中二口恶英类化合物污染调查分析

目的调查陕西省10个地市典型的动物源性食品中二口恶英类化合物的污染情况。方法于2017年4月采集具有代表性的食品(猪肉、牛肉、鱼肉、鸡蛋),采用高分辨气相色谱-高分辨双聚焦磁式质谱联用仪定量检测29种二口恶英类化合物的含量。结果 4种食品中鱼肉的毒性当量(toxic equivalent quantity,TEQ)最大,为0. 085 pg TEQ/g,猪肉、牛肉和鸡蛋中TEQ值分别为0. 049、0. 034和0. 040 pg TEQ/g。从地域分布来看,二口恶英含量较大的样品包括安康的鱼肉样品和汉中的猪肉样品,但均低于欧盟所规定该食品种类限值。结合膳食消费量,计算获得4种食品的每月总膳食摄入量为2. 01 pg TEQ/kg,远低于联合国粮农组织/世界卫生组织食品添加剂联合委员会规定的每月耐受量70 pg TEQ/kg。结论陕西省10个地市居民由二口恶英类化合物摄入而导致的健康风险处于较低水平。     

奶粉中二噁英类化合物的检测

目的　采用高分辨气相色谱 /高分辨双聚焦磁式质谱联用仪 (HRGC/HRMS)定量检测奶粉中二英类化合物。方法　采用索式抽提和自动纯化系统等仪器对奶粉样品中的二英组分进行纯化和富集 ,采用同位素稀释法 ,以HRGC/HRMS联用仪检测。结果　同位素标准物的回收率分布于 90 6%～ 116 3 %之间 ,CRM 5 3 4的检测结果均在标准值范围之内 ,3次实验结果的RSD <2 0 % ,该方法检测下限可达pg/g水平。 结论　该方法灵敏、定性、定量准确 ,为目前国际上权威机构认可的二英定量检测方法。     

奶粉中二恶英含量分析

目的：建立高分辨气相色谱／高分辨双聚焦磁式质谱联用（HRGC／HRMS）定量检测奶粉中二恶英的检测方法，并采用该方法对市售奶粉进行实际检测。方法：采用索式抽提和FMS专用净化装置对样品进行纯化和富集，以HRGC／HRMS－多离子检测方式对样品中的PCDDs/Fs进行定性和分析，用同位素稀释技术定量（精确到pg/g即ppt水平）。结果：该方法的检测限TCDF和TCDD分别为0.02pg/μL和0.01pg/μL。参考化合物（CRM）对方法的验证结果均在国际认可的范围内，三次检测数据的相对标准偏差＜10％。该奶粉样品奶粉中PCDDs和PCDFs的总浓度是0.79pg/g（全重计），以WHO TEF为依据计算所得的样品全重总TEQ值是0.137pg TEQ/g，脂肪的总TEQ值是0.526pg TEQ/g。结论：该奶粉样品被二恶英污染，目前我国未制定各类食物样品中二恶英污染的限量标准，因此无法对该样品的污染程度进行评价。该方法定性、定量准确，为目前国际上权威认可的二恶英定量检测方法。     

高血糖、高血脂与超重和肥胖关系的研究

目的 探讨高血糖、高血脂与超重和肥胖的关系. 方法对在我院健康体检的20岁以上男性居民1 047人进行空腹血糖(FPG)、血清总胆固醇(TC)、甘油三酯(TG)检测,同时测量身高、体重,计算体重指数(BMI),并对相关资料进行统计分析. 结果调查对象中超重与肥胖的罹患率分别为43.55%、14.90%;体重过低、正常、超重、肥胖四组人群的空腹血糖受损患病率(分别为0.00%、3.59%、6.14%、14.74%)、糖尿病患病率(分别为0.00%、5.02%、6.36%、14.10%)、高TC患病率(分别为17.65%、20.81%、27.85%、33.33%)、高TG患病率(分别为5.88%、27.27%、49.12%、62.82%),差异均有统计学意义(χ2=29.835、20.791、11.672、83.695,P均＜0.01);不同体重指数组的FPG、TC、TG水平差异均有统计学意义(F=7.966、6.957、32.498,P均＜0.01). 结论平均空腹血糖、总胆固醇、甘油三酯值随着体重指数的增大而显著增高,空腹血糖受损、糖尿病、高胆固醇、高甘油三酯的患病率也随体重指数的增大而显著增高.     

A Perspective in High/Scope's Early Education Research

The curriculum study, operating in the public schools of Ypsilanti, Michigan, served three‐ and four‐year old disadvantaged children. The children were randomly assigned to one of three models: a programmed learning, direct‐instruction approach, a child‐centered nursery school approach, and an open‐framework cognitive‐developmental approach. At fifteen years, the intellectual achievements of children from all three groups did not differ.

However, significant differences were found in social‐behavioral outcomes. Structured learning youngsters reported lesser degree of sports participation, five times as many acts of property violence and twice as many acts of drug abuse or status offenses. Program model does make a difference in social adjustment of the children served.     

A Perspective in High/Scope's Early Education Research

The curriculum study, operating in the public schools of Ypsilanti, Michigan, served three- and four-year old disadvantaged children. The children were randomly assigned to one of three models: a programmed learning, direct-instruction approach, a child-centered nursery school approach, and an open-framework cognitive-developmental approach. At fifteen years, the intellectual achievements of children from all three groups did not differ.

However, significant differences were found in social-behavioral outcomes. Structured learning youngsters reported lesser degree of sports participation, five times as many acts of property violence and twice as many acts of drug abuse or status offenses. Program model does make a difference in social adjustment of the children served.     

Improvement of Hypertriglyceridemia by Roasted Nelumbinis folium in High Fat/High Cholesterol Diet Rat Model

Hypertriglyceridemia is a condition characterized by high triglyceride levels and is a major risk factor for the development of cardiovascular diseases. The present study was designed to investigate the inhibitory effect of roasted Nelumbinis folium (RN), which is a medicinal substance produced by heating lotus leaves, on lipid metabolism in high fat/cholesterol (HFC) diet-induced hypertriglyceridemia. Except for those in the control group, Sprague–Dawley rats were fed an HFC diet for four weeks to induce hypertriglyceridemia. During the next nine weeks, the control, regular diet; HFC, HFC diet, FLU, fluvastatin (3 mg/kg/day); RNL, RN (100 mg/kg/day); RNH, RN (200 mg/kg/day) were orally administered together with the diet, and the experiments were conducted for a total of 13 weeks. The weight of the epididymal adipose tissue, liver, and heart of rats in the HFC diet group significantly increased compared to those in the control group but improved in the RN-treated group. It was also confirmed that vascular function, which is damaged by an HFC diet, was improved after RN treatment. The levels of insulin, glucose, triglycerides, total cholesterol, and low-density lipoprotein increased in the HFC diet group compared to those in the control group, while the administration of RN attenuated these parameters. In addition, the administration of RN significantly reduced the gene expression of both LXR and SREBP-1, which indicated the inhibitory effect of the biosynthesis of triglycerides caused by RN. The results indicated that RN administration resulted in an improvement in the overall lipid metabolism and a decrease in the concentration of triglycerides in the HFC diet-induced rat model of hypertriglyceridemia. Therefore, our findings suggest that the RN can be a candidate material to provide a new direction for treating hypertriglyceridemia.     

Interaction of Protein Preloads and Physical Activity on Intake of an Ultra-Processed,High Sugar/High Fat Food/Low Protein Food

“Loss of control, LOC” eating is a major contributor to the development of obesity. Dietary protein is known to promote satiety, but little attention has been paid to the ability of protein, consumed in close proximity to snacking (20 min), to reduce the intake of ultra-processed, low-protein snack foods. We hypothesized that a high-protein preload (HP, 8 g of protein) consumed in close proximity to eating an ultra-processed snack food would reduce intake of the snack food as compared to a low-protein preload (LP, 1.2 g of protein). Two laboratory test meals were conducted, and the intake of ice cream (1.99 kcal/gram) after consuming dairy-based liquid preloads was measured. Habitual physical activity, a potential modulator of satiety, was assessed by a self-reporting questionnaire. Thirty (responders) out of 50 participants reduced their intake of ice cream after the HP preload, with a significant difference in intake observed between the responders and non-responders (−30 ± 25 and 18 ± 18 g, F (1, 49) = 54.36, p < 0.001 for responders and non-responders, respectively). Our data demonstrate that protein consumed in close proximity to ultra-processed snack food can reduce caloric intake by ~60 kcal, which could potentially reduce body weight by at least 5 pounds per year.     

高糖高脂诱导新西兰兔肝纤维化的实验研究

目的采用高糖高脂喂养新西兰兔,建立肝纤维化动物模型,研究饮食对肝纤维化的影响。方法将雄性新西兰兔20只随机分为2组,10只饲以基础饲料为对照组;10只饲以高糖高脂饲料为模型组,每月末抽取空腹血样,测血糖和甘油三酯(TG)水平。5个月后取肝脏,测定组织匀浆中羟脯氨酸(Hyp)含量,HE和VG染色观察肝脂肪变性、炎症和纤维化情况,免疫组织化学法观察肝组织Ⅳ型胶原和转化生长因子β1(TGF-β1)的表达情况。结果与对照组相比,模型组1月后即出现高TG血症,3月后出现血糖升高,肝组织Hyp含量增加,并出现脂肪变性,淋巴细胞浸润,胶原纤维增生,肝组织Ⅳ型胶原和TGF-β1的蛋白表达明显增加。结论高糖高脂饲料对新西兰兔具有肝毒性,可促进TGF-β1的表达,增加Ⅳ型胶原的合成而诱导肝纤维化的形成。