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《食品工业》2020,(9)
建立使用盐酸超声波辅助提取HPLC-ICP-MS联用技术测定水产品及制品中甲基汞的分析方法。水产品及制品用5 mol/L盐酸提取,超声水浴提取60 min。流动相A为0.01 mmol/L乙酸铵+0.3%L-半胱氨酸(p H 3.0),流动相B为甲醇, V (流动相A)︰V (流动相B)=97︰3。使用C18反相高效液相色谱柱(4.6 mm×250 mm, 5μm)等度洗脱,202Hg为ICP-MS的检测离子,可6 min实现2种形态汞的完全分离。该方法的线性范围为0~10 ng/m L (r≥0.999 8),检出限为0.9μg/kg,加标回收率为80.8%~100%, RSD为0.80%~4.55%(n=6)。该方法分离时间短、准确、简便、可行、易于操作,在实验室检测方面具有一定的应用价值。 相似文献
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目的:采用两泵一阀的在线固相萃取-高效液相色谱技术建立一种能够快速检测食品中胡萝卜素的方法,避免了胡萝卜素在复杂前处理过程中的损失。方法:在线固相萃取柱PLRP-S(2.1 mm×12.5 mm)液相分离色谱柱PAH (2.1 mm×100 mm,1.8μm);固相萃取泵流动相,水+甲醇,液相分离流动相,甲醇+二氯甲烷;检测波长450 nm。结果:该方法在0.10~2.00μg/mL保持良好的线性,方法的检出限和定量限均能够满足检测需求。α-胡萝卜素回收率为92.0%~105.4%,β-胡萝卜素回收率91.1%~107.2%。结论:该方法利用两泵一阀的在线固相萃取技术,能高效、快速检测食品中胡萝卜素,检测效率高,前处理提取效率好,方法能够满足检测需要。 相似文献
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HPLC/ESI-MS测定减肥保健食品中的双去甲基西布曲明 总被引:1,自引:0,他引:1
目的建立高效液相色谱质谱联用技术(HPLC/ESI-MS)的测定方法,测定保健食品中双去甲基西布曲明。方法色谱条件为Johnson Spherigel C18色谱柱(4.6mm×250mm,5μm);流动相:流动相A液(0.25%乙酸+20mmol/L乙酸铵),流动相B液(甲醇)=25+75(体积比),流速1ml/min,检测波长223nm。质谱采用电喷雾正离子模式(ESI+),分子离子峰m/z252。结果双去甲基西布曲明在0.01~1.20mg/ml范围内,浓度与峰面积呈良好的线性关系,最低检出限为0.95μg/ml(S/N=3)。结论本方法流动相简单,分析时间短且试样预处理简单,灵敏度高,借助质谱的定性能力,可大大提高方法可靠性和抗干扰能力,能准确快速地测定保健食品中的双去甲基西布曲明。 相似文献
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为了测定保健食品中的生物素的含量,建立方便可靠的测定方法,采用高效液相色谱法对保健食品中生物素含量进行了测定。使用HypersilODS色谱柱(4.6mm×250mm,5μm),以乙腈+0.05mol L磷酸二氢钾(15+85,pH=3.5)为流动相,检测波长200nm。方法的加标回收率为86.8%~106.0%,RSD为8.4%,最低检出量为0.5mg kg。该方法简便、准确,有良好的重现性,技术参数指标符合食品理化分析的要求。 相似文献
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为提高胡萝卜素的分离水平,在相同的HPLC条件下比较了C30与C18柱对番茄和胡萝卜中类胡萝卜素的分离情况.比较的色谱条件为C30固定相YMCTM Carotenoid S-5柱(YMC,250 mm×4.6 mm,5μl);C18固定相DIAMONSILTM柱(Dikma Technologies,250 mm×4.6 mm,5 μl);流动相A乙腈+水=9+1;流动相B乙酸乙酯;线性梯度洗脱在前15 min内,B由0%增为100%,随后,B保持100%,流速为1.0 ml/min,检测波长为450 nm,进样量为20μl,室温.从二者色谱图的比较可以看出,C30柱反相高效液相色谱在分离几何异构体上显示出明显的优势,可有效分离成分复杂、多样、结构相似的不合氧类胡萝卜素顺反异构体.可以认为,C30柱在分析食品中类胡萝卜素组分的领域中具有良好的应用前景. 相似文献
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建立了纺织品中富马酸二甲酯的固相萃取-高效液相色谱检测方法。样品经超声提取后,用固相萃取进行净化,Kromasil C18 柱(250 mm × 4.6 mm i.d., 5 μm)分离,采用乙腈+水(55+45, V/V)为流动相,紫外检测波长为220 nm,外标法定量。实验结果表明:富马酸二甲酯在0.05~50.0 mg/L的浓度范围内呈良好的线性关系,最低检出限LOD为0.05mg/kg,定量检出限LOQ为0.15 mg/kg 。方法回收率在91.2~102.1%之间,平均回收率为96.4%,RSD 为1.3~3.9% 。所建实验方法快速、简便、干扰少,能满足纺织品中富马酸二甲酯的测定要求。 相似文献
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为建立一种在C30-HPLC 上使用外标法对番茄红素全反式异构体进行定量检测的方法,采用色谱条件:固定相:YMC Carotenoid columu C30 色谱柱(4.6mm × 250mm,SOD-5μm,Waters);流动相A:乙腈- 甲醇(3:1,V/V);流动相B:甲基叔丁基醚(MTBE);流动相A 与B 中分别添加0.05%(V/V)的三乙胺;线性梯度洗脱:B 在20min 内由0 增至80%,20~35min 内B 维持在80%;流速:1mL/min;色谱图检测波长470nm;进样量:20μL;柱温:室温。结果表明:此方法的最小定量限为0.10μg/mL,在10~100μg/mL 范围内质量浓度与组分峰面积的线性回归方程为y=212181x,R2=0.9738。相对标准偏差为4.04%。外标加样回收率为97.34%(RSD 为0.904%)。应用本方法可对番茄果实中的全反式番茄红素进行定量分析。 相似文献
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Two experiments compared follicular and luteal development and circulating steroid concentrations from induced luteolysis to ovulation in lactating Holstein cows (n = 27; 40.0 +/- 1.5 kg milk/day) vs. nulliparous heifers (n = 28; 11 to 17 mo-old) during summer (Experiment 1), and in lactating (n = 27; 45.9 +/- 1.4 kg milk/d) vs. dry cows (n = 26) during winter (experiment 2). All females received PGF2,, 6 d after ovulation and were monitored until next ovulation by daily ultrasound and assay of serum progesterone (P4) and estradiol (E2). Every female was used two or three times. In Experiment 1, lactating cows had high incidence of multiple ovulation (63.5%) compared with heifers (1.3%). Among single ovulators, there was no difference in maximal size of ovulatory follicles between lactating cows and heifers (15.8 vs. 16.5 mm, respectively). However, lactating cows had lower peak serum E2 (8.6 vs. 12.1 pg/ml), took longer to ovulate after luteolysis (4.6 vs. 3.8 d), developed more luteal tissue volume (7,293.6 vs. 5,515.2 mm3), and had lower serum P4 on d 6 after ovulation (2.0 vs. 3.0 ng/ml) than heifers (data included multiple ovulators). In experiment 2, multiple ovulations were similar between lactating and dry cows (17.9 vs. 17.2%, respectively). Peak serum E2 was also similar between lactating and dry cows (7.6 vs. 8.5 pg/ml) although lactating cows had larger ovulatory follicles (18.6 vs. 16.2 +/- 0.4 mm). Lactating cows took longer to ovulate (4.8 vs. 4.2 d), developed more luteal tissue (7,599 vs. 5,139 +/- 468 mm3), but had similar serum P4 (2.2 vs. 1.9 ng/ ml) compared with dry cows. Therefore, lactating cows had similar or lower circulating steroid concentrations than dry cows or heifers, respectively, despite having larger ovarian structures. 相似文献
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Fertilization and early embryonic development in heifers and lactating cows in summer and lactating and dry cows in winter 总被引:2,自引:0,他引:2
Sartori R Sartor-Bergfelt R Mertens SA Guenther JN Parrish JJ Wiltbank MC 《Journal of dairy science》2002,85(11):2803-2812
Two experiments in two seasons evaluated fertilization rate and embryonic development in dairy cattle. Experiment 1 (summer) compared lactating Holstein cows (n = 27; 97.3 +/- 4.1 d postpartum [dppl; 40.0 +/- 1.5 kg milk/d) to nulliparous heifers (n = 28; 11 to 17 mo old). Experiment 2 (winter) compared lactating cows (n = 27; 46.4 +/- 1.6 dpp; 45.9 +/- 1.4 kg milk/d) to dry cows (n = 26). Inseminations based on estrus included combined semen from four high-fertility bulls. Embryos and oocytes recovered 5 d after ovulation were evaluated for fertilization, embryo quality (1 = excellent to 5 = degenerate), nuclei/embryo, and accessory sperm. In experiment 1, 21 embryos and 17 unfertilized oocytes (UFO) were recovered from lactating cows versus 32 embryos and no UFO from heifers (55% vs. 100% fertilization). Embryos from lactating cows had inferior quality scores (3.8 +/- 0.4 vs. 2.2 +/- 0.3), fewer nuclei/embryo (19.3 +/- 3.7 vs. 36.8 +/- 3.0) but more accessory sperm (37.3 +/- 5.8 vs. 22.4 +/- 5.5/embryo) than embryos from heifers. Sperm were attached to 80% of UFO (17.8 +/- 12.1 sperm/UFO). In experiment 2, lactating cows yielded 36 embryos and 5 UFO versus 34 embryos and 4 UFO from dry cows (87.8 vs. 89.5% fertilization). Embryo quality from lactating cows was inferior to dry cows (3.1 +/- 0.3 vs. 2.2 +/- 0.3), but embryos had similar numbers of nuclei (27.2 +/- 2.7 vs. 30.6 +/- 2.1) and accessory sperm (42.0 +/- 9.4 vs. 36.5 +/- 6.3). From 53% of the flushings from lactating cows and 28% from dry cows, only nonviable embryos were collected. Thus, embryos of lactating dairy cows were detectably inferior to embryos from nonlactating females as early as 5 d after ovulation, with a surprisingly high percentage of nonviable embryos. In addition, fertilization rate was reduced only in summer, apparently due to an effect of heat stress on the oocyte. 相似文献
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目的 建立超高效液相色谱-串联质谱法同时测定蔬菜和鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈亚砜), 并对深圳市售的蔬菜和鸡蛋中氟虫腈及其代谢物残留状况进行抽样检测。方法 采用QuEChERS前处理方法, 以C18色谱柱为分离柱, 以乙腈和10 mmol甲酸+6 mmol甲酸铵水溶液为流动相进行梯度洗脱, 用超高效液相色谱-串联质谱(ultra performance liquid chromatography-mass spectrometry/mass spectrometry, UPLC-MS/MS), 电喷雾电离(electrospray ionization, ESI), 多反应监测(multiple reaction monitoring, MRM)模式检测, 外标法同时定量测定氟虫腈及其代谢物。结果 方法的线性范围为0.1~2.0 μg/L, 线性相关系数均大于0.9994, 检出限0.0005 mg/kg, 定量限0.001 mg/kg; 蔬菜中3个水平的平均加标回收率88.0%~101.2%, 相对标准偏差(relative standard deviation, RSD)均小于8.5%; 鸡蛋中3个水平的平均加标回收率86.1%~104.8%, 相对标准偏差(RSD)均小于9.2%。结论 该方法具有操作简单、干扰少、快速、准确可靠等特点, 可适用于蔬菜鸡蛋中氟虫腈及其代谢物的检测。 相似文献
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Several cereals and pulses commonly consumed in India were screened for zinc and iron contents and their bioaccessibility in the same was determined by equilibrium dialysis employing an in vitro simulated digestion procedure. Zinc content of cereals ranged from 1.08 mg/100 g in rice to 2.24 mg/100 g in sorghum. Zinc content of pulses was between 2.03 mg/100 g (whole chickpea) and 2.68 mg/ 100 g (decorticated chickpea). Iron content of cereals ranged from 1.32 mg% in rice to 6.51 mg% in sorghum, while that of pulses ranged from 3.85 mg% in decorticated green gram to 6.46 mg% in black gram. Dialyzability of zinc from pulses (27–56%) was generally higher than that from cereals (5.5–21.4%). Dialyzabilities of iron were almost similar from both cereals and pulses examined and were 4.13–8.05% in cereals and 1.77–10.2 % in pulses. A significant negative correlation between inherent phytate content and zinc dialyzability value was inferred in the case of pulses. Phytic acid content of the cereals had a significant negative influence on iron dialyzability. Inherent calcium had a negative influence on zinc dialyzability in cereals. Tannin did not have any significant influence on zinc or iron dialyzabilities from cereals and pulses. While both insoluble and soluble fractions of the dietary fibre generally interfered with zinc dialyzability, the insoluble fraction alone had this effect on iron dialyzability. The lower collective negative influence of the inherent factors on zinc dialyzability from pulses is consistent with their higher concentrations in these grains, relative to cereals. The negative correlation of inherent phytic acid with zinc and iron dialyzabilities was supported by enhanced dialyzabilities of these minerals upon partial removal of phytate from the grains by treatment with fungal phytase. 相似文献
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A. Sharma M. Gupta 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(1):97-104
Fenvalerate is a non-systemic insecticide/acaricide used in controlling a wide range of pests, including those resistant to organochlorine, organophosphorus and carbamate insecticides. The study investigated the dissipation behaviour (residue level) of fenvalerate in tea and its transfer during infusion. Fenvalerate was applied on tea crop at two dosages, 100 and 200?g a.i.?ha?1 (recommended and double the recommended) in the dry and wet seasons under field conditions. Samples (green tea shoots, made tea, its infusion and spent leaves) were analysed for fenvalerate by high-performance liquid chromatography using diode array detection. The residue dissipated faster in the wet season than in the dry season. Seven days after the treatment (normal round of plucking) the residues observed in the green shoots at the two dosages were 0.5?±?0.01, 1.1?±?0.01 and 0.4?±?0.02, 0.9?±?0.01?mg?kg?1 in the dry and wet seasons, respectively. During processing of green tea shoots to made tea a 30–40% loss of residue was observed. The transfer of residue from made tea to infusion was in the range 10–30% for both seasons, whereas 50–70% of the residues remained in the spent leaves. However, the degradation rate in both seasons followed first-order kinetics. The half-lives were in the range of 2–3 days for green shoots and made tea in both seasons. 相似文献
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蛋白质组学技术及其在乳及乳制品中的应用研究进展 总被引:1,自引:0,他引:1
蛋白质组学技术是近年来生命科学研究的重要工具,在食品、医学及动植物研究领域具有独特优势。利用蛋白质组学技术研究乳及乳制品,深入阐明其中蛋白质的表达及动态变化已成为当前的研究热点。该文主要综述了蛋白质组学的概念、常用技术及应用领域,重点介绍蛋白质组学在乳及乳制品领域,特别是在乳脂肪球膜蛋白、乳清蛋白、乳及乳制品加工过程以及干酪制品中的研究应用,探讨了目前乳及乳制品蛋白质组学研究中存在的问题与局限,并对蛋白质组学及其在乳及乳制品中的应用前景进行了总结与展望,为应用蛋白质组学技术深入研究乳及乳制品提供了理论依据。 相似文献
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目的 调查我国熟制坚果与籽类食品中霉菌及其毒素污染状况,掌握该类食品中霉菌及真菌毒素污染风险的关联性。方法 通过采集市售商品,检测霉菌及其毒素,采用内转录间区(ITS)测序法对样品中污染的霉菌进行属鉴定。结果 19.32%(560/2 912)的熟制坚果与籽类食品霉菌计数>25 CFU/g。单一、混合坚果超过该限值的比例分别为14.78%(322/2 178)和32.56%(239/734),差异有统计学意义(P<0.05)。单一坚果中核桃超过该限值的比例最高,为24.10%(47/195),杏仁、巴达木和花生分别为17.44%(15/86)、16.81%(20/119)和16.22%(73/450),其余种类均在15%以下。对26份霉菌计数>25 CFU/g的样品进行真菌毒素检测,1份采自云南的花生检出白僵菌素污染量为16.37 μg/kg。ITS扩增子测序发现熟制坚果与籽类食品中主要污染曲霉属、交链孢霉属、念珠菌属等,和真菌毒素检出有相关性。结论 熟制坚果与籽类食品中霉菌污染较高,检出的霉菌属有产真菌毒素的风险,提示应加强该类食品中污染霉菌的监测、种属鉴定及产毒情况研究,掌握其污染途径和产毒规律,为开展风险评估,采取有效防控措施提供科学依据。 相似文献
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《International Dairy Journal》2005,15(5):485-493
Sweetness–aroma interactions were investigated in model dairy desserts varying in sucrose concentration, aroma concentration and in textural characteristics using different textural agents (κ-, ι-, λ-carrageenans and an equal-mix of the three). Overall intensities of sweetness and aroma perceptions were evaluated by sensory analysis and apparent partition coefficients of aroma compounds were measured by static headspace—GC.Sweetness–aroma interaction was characterised by a non-reciprocal relationship. Concentration of aroma had no impact on sweetness intensity, whatever be the sucrose concentration or textural characteristics of desserts, whereas varying texture or sucrose concentration modified aroma intensity. However, effects on aroma assessment were effective only when aroma concentration was the highest. In this condition, use of λ-carrageenan or increasing sucrose concentration from 25 to 50 g kg−1 enhanced aroma intensity, but no extra enhancement was observed when sucrose concentration was 100 g kg−1. As the air–dessert partition coefficient remained constant, impact of textural characteristics and sweetness variation on aroma perception did not result from physico-chemical interaction. 相似文献