粮食中有机磷农药残留成因及检测技术分析

随着我国社会和经济的不断进步发展,作为粮食产业大国,同时也是农药生产量和使用量较大的国家,农药的使用会对我国粮食产量产生直接的影响,目前农民对于农药的使用认知存在误区,甚至误以为增加农药的使用量可以提高粮食产量。农药中杀虫剂的使用量大,农药残留已经成为威胁人类健康的大问题。本文针对粮食中有机磷农药残留的原因进行了讨论,探索了粮食中有机磷农药残留检测技术的应用,包括色谱分析法、光谱分析法等。     

舌尖上的保卫者 “酶抑制率法”

正农药残留是指农药使用后残存于环境、生物体和食品中的农药母体、衍生物、代谢物、降解物和杂质的总称。有机磷类和氨基甲酸酯类农药是目前使用量最大的农药品种,在蔬菜中具有较高的检出率。当前,高毒禁用农药,特别是有机磷类农药仍为蔬菜农药残留超标的主体,但其也是菜农首选的一类杀虫剂。针对有机磷和氨基甲     

三种农药残留量速测方法的对比性实验研究

由于农药滥用或使用不当 ,农药残留严重地影响着人类的健康。我国目前农药残留较为突出的是蔬菜中的农药残留问题。[1] 近年来蔬菜被农药污染的情况有增无减 ,有机磷农药残留尤为突出。控制蔬菜中农药残留对人体的危害 ,最为有效的方法之一是加强对蔬菜中的农药残留检测的力度。蔬菜上农药残留的抽样检测 ,在许多发达国家早已制度化 ,从而有效地控制了农药残留量超标的蔬菜。在我国 ,蔬菜生产不是采用集中大规模生产和专门销售的产销方式 ,而是相对分散生产 ,即采即卖的销售方式。常用的农药残留理化分析方法不但要昂贵的气相色谱等分析仪器…     

水果蔬菜中有机磷农药残留的快速检测方式分析

水果蔬菜中的有机磷农药残留问题已成为我国质量检测行业目前关注的热点问题,严重影响食品的安全,农药残留的快速检测方法被广泛应用到水果蔬菜中的残留农药的检测工作中。基于此,对农药残留快速检测的方法及其产品的现状进行研究,讨论有机农药残留的快速检测实验过程与结果,总结出经济快速的检验有机磷农药残留量的方法,有效控制水果蔬菜中的农药残留量,保证食品的安全。     

食品中有机磷农药检测方法研究进展

有机磷农药作为一类高效、广谱的杀虫剂、除草剂等正被广泛地用于农业生产中。但其大量使用后对人、动物和环境产生的危害也日益严重。由于近些年来食品安全问题已经引起了越来越多人的关注，对食品中有机磷农药残留的检测研究已经引起了包括我国在内的世界各国的重视。在总结前人工作的基础上对食品中有机磷农药常用的检测方法做一综述。     

对5种去除蔬菜中残留有机磷农药的处理方法的效果分析

正随着人们对自身健康越来越关注,蔬菜中的农药残留逐渐成为老百姓担心的问题。但有部分农业生产者为了能够进一步提高农作物的产值,就增加农药的使用量,导致蔬菜中残留了较多的农药。人们一旦食用了,就会出现恶心、呕吐等不良症状,甚至会危及到人们的生命安全。因此,需要我们采用科学、合理的处理方法,对蔬菜中的农药残留予以去除。有机磷农药是我国使用最多的农药种类,为此,我选用了5种人们常用的处理方法对蔬菜中残留的有机磷     

气相色谱三重四极杆质谱TSQ Quantum XLS用于芹菜及黄瓜基质中4种有机磷农药的分析

1.前言有机磷农药常被用作杀虫剂喷洒在果树蔬菜上,虽然它比有机氯农药较易降解,残留期较短,但有机磷农药毒性也较高,如果这类农药进入有机体,会引起神经功能紊乱,从而导致肌体的损害。早期的一些有机磷农药毒性较大,残留较多,有些品种已经被淘汰或正在被淘汰,而我国农药市场比较复杂,在某些地方,一些被淘汰的品种还在继续被使用。其中甲胺磷,对硫磷由于其毒害巨大,已经被列为禁用的农药,所以在检测有机磷农药残留时,就要求提供更高灵敏度的仪器进行检测。并且由于有机磷农     

酶抑制法快速检测蔬菜中有机磷和氨基甲酸酯类农药残留的研究现状及展望

概述了酶抑制法快速检测蔬菜中有机磷和氨基甲酸酯类农药残留技术的研究现状、检测原理、应用情况和存在的问题。酶抑制法具有检测时间短、成本低、操作简便等特点,是目前我国控制农药残留的一种有效的初筛方法。     

食品中有机磷农药残留检测技术研究进展

<正>有机磷农药类型较多,应用最广泛的是硫代磷酸酯类或磷酸酯类。由于有机磷农药对人体内的乙胆碱酯酶具有抑制作用,造成人体内乙胆碱酯在人体内积累,从而引起神经性疾病。由于人们在农业生产中过度施用OPPs,因此其残留问题越来越受到人们的关注。它们常常残留在蔬菜、水果及大米、玉米等农作物中,且能够通过食物链在人体内     

2009年大连市部分食品中化学污染物监测分析

目的了解大连市部分食品中重金属、有机磷及氨基甲酸酯农药残留、有机氯及菊酯农药残留以及环己基氨基磺酸钠的污染现状,对食品安全进行有效控制。方法按GB/T 5009—2003《食品卫生检验方法理化部分》检测铅、镉、汞、有机氯及菊酯农药残留、环己基氨基磺酸钠、有机磷及氨基甲酸酯农药残留。结果 39份样品中铅超标5份;镉和汞无超标样品。50份蔬菜样品中检出毒死蜱农药残留1份,超标1份;氯氰菊酯农药残留2份,超标1份。10份茶叶样品中检出联苯菊酯农药残留1份,无超标样品。有机磷及氨基甲酸酯农药、有机氯及菊酯农药、环己基氨基磺酸钠均无检出。结论大连市部分水产品中铅含量较高,污染较明显。需要进一步加强监测,控制污染。农药残留水平较低,只在个别蔬菜和茶叶中有不同程度的检出。     

Ovarian structures and circulating steroids in heifers and lactating cows in summer and lactating and dry cows in winter

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.     

Fertilization and early embryonic development in heifers and lactating cows in summer and lactating and dry cows in winter

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.     

2018年深圳市售蔬菜和鸡蛋中氟虫腈及其代谢物的检测分析

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。     

Sweetness and aroma perceptions in dairy desserts varying in sucrose and aroma levels and in textural agent

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.     

芝麻饼粕及其在烟草上应用研究现状

概述了芝麻饼粕的有效营养成分及其作为有机肥的加工方法,介绍了芝麻饼粕在烟草生产上的应用效果。并就进一步促进芝麻饼粕在烟草上的应用提出了建议,以期为烟叶生产过程中科学使用芝麻饼粕提供参考资料。     

Aluminium and fluoride in hospital daily diets and in teas

The levels of aluminium and fluoride have been determined in hospital daily diets including breakfast, dinner and supper, as well as in black teas and herbal teas purchased from the local market. In tea, aluminium was determined directly in a sample solution by atomic absorption spectroscopy using nitrous oxide and an acetylene flame. For analysis of the hospital diet, samples containing lower levels of aluminium were analysed using a spectrophotometric method which measured aluminium in the form of a 8-hydroxyquinoline complex. Decomposition of the samples was achieved using a mixture of concentrated acids [nitric (HNO₃), perchloric (HClO₄) and sulphuric (H₂SO₄)] in platinum dishes. Fluoride was assayed by spectrophotometry using a microdiffusion procedure with a mixture of concentrated HClO₄ and silver sulphate, trace amounts of the released fluoride [as hydrogen fluoride (HF)] were trapped on the alkaline surface of a Petri dish and then determined in the form of an alizarin-fluoride complex. The mean level of aluminium found in hospital daily diets amounted to 21.3±12.3 mg and the mean level of fluoride was 1.38±1.12 mg per adult person. In the 16 samples of commercially available brands of black teas, the levels of aluminium and fluroide ranged from 445 to 1552 ppm (mean=897±264 ppm) and from 30 to 340 ppm (mean 141±85 ppm), respectively. In six herbal teas, the mean levels of aluminium and fluoride were lower, and amounted to 218.9±150.7 ppm and 6.0±6.9 ppm, respectively. This study has shown that concern about a high intake of aluminium and fluoride from these foods is unfounded.     

Heavy metals in vegetables grown in the Netherlands and in domestic and imported fruits

Summary The contents of cadmium, lead mercury, copper, manganese and zinc in 242 samples of 37 different species of domestic and imported fruits have been determined. Also contents of the same heavy metals, except mercury, have been determined in 205 samples of 7 species of domestic vegetables (lettuce, spinach, endive, beetroots, onions, celeriac and Swedish turnips). The median contents (in mg/kg fresh mass of the edible part) found for fruits are: Cd 0.002; Pb 0.017; Hg 0.002; Cu 0.61; Mn 0.52 and Zn 0.99. In the vegetables median levels have been found (mg/kg) of 0.009–0.073 for Cd, 0.01–0.03 for Pb, <0.2–0.3 for Cu, 0.69–1.41 for Mn and 0.95–5.5 for Zn. The contribution of fruits to the tolerable daily intakes of Cd, Pb and Hg is, for an average consumption pattern, less than 1%. On the other hand, the contribution to the recommended amounts of the essential elements Cu, Mn, and Zn is no more than 1%–3%. From the vegetables an average portion of spinach contains 19% and 2.6% of the tolerable daily amounts of Cd and Pb, respectively. For the other species of vegetables these figures are less than 5% for Cd (except for endive, 6.8%) and for lead less than 1%. Spinach contributes considerably to the need for Cu, Mn and Zn, in general more than 10% of the recommended daily amounts. The other species of vegetables contribute only from less than 1% to less than few percents.

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Schwermetalle in niederländischen Gemüsen und in inländischem und importiertem Obst

Zusammenfassung Es wurde der Gehalt an Cadmium, Blei, Quecksilber, Kupfer, Mangan und Zink in 242 Proben von 37 verschiedenen Fruchtarten, landeseigenen und importierten, bestimmt. Darüber hinaus wurde der Gehalt der gleichen Schwermetalle, außer Qeucksilber, in 205 Proben von 7 Sorten landeseigenen Gemüsen, Kopfsalat, Spinat, Endivie, rote Rüben, Zwiebeln, Sellerie und Kohlrüben ermittelt. Die Medianwerte (in mg/kg Frischsubstanz des eßbaren Anteils) für die Fruchtproben sind: Cd 0,002; Pb 0,017; Hg 0,002; Cu 0,61; Mn 0,52; Zn 0,99. In den Gemüsen betrugen die Medianwerte (mg/kg) für Cd 0,009–0,073, für Pb 0,01–0,03, für Cu <0,2–1,3, für Mn 0,69–1,41 und für Zn 0,95–5,5. Der Anteil an den duldbaren täglichen Aufnahmemengen für Cd, Pb und Hg liegt bei durchschnittlichem Verzehr von Früchten unterhalb 1%. Andererseits ist der Anteil der Früchte an den empfohlenen Mengen für die essentiellen Spurenelemente Cu, Mn und Zn bei normalem Verzehr auch nur 1%–3%. Bei den Gemüsen liefert eine Tagesportion Spinat im Durchschnitt 19% bzw. 2,6% der duldbaren täglichen Menge an Cd bzw. an Pb; bei den übrigen Gemüsearten macht das Cd weniger als 5% (außer Endivie 6,8%) und das Pb weniger als 1% aus. Spinat liefert einen wesentlichen Anteil des Bedarfs an Cu, Mn und Zn von über 10%. Der Beitrag der übrigen Gemüsearten ist im Durchschnitt nur einige Prozent.

     

Heavy metals in vegetables grown in The Netherlands and in domestic and imported fruits

The contents of cadmium, lead mercury, copper, manganese and zinc in 242 samples of 37 different species of domestic and imported fruits have been determined. Also contents of the same heavy metals, except mercury, have been determined in 205 samples of 7 species of domestic vegetables (lettuce, spinach, endive, beetroots, onions, celeriac and Swedish turnips). The median contents (in mg/kg fresh mass of the edible part) found for fruits are: Cd 0.002; Pb 0.017; Hg 0.002; Cu 0.61; Mn 0.52 and Zn 0.99. In the vegetables median levels have been found (mg/kg) of 0.009-0.073 for Cd, 0.01-0.03 for Pb, less than 0.2-0.3 for Cu, 0.69-1.41 for Mn and 0.95-5.5 for Zn. The contribution of fruits to the tolerable daily intakes of Cd, Pb and Hg is, for an average consumption pattern, less than 1%. On the other hand, the contribution to the recommended amounts of the essential elements Cu, Mn, and Zn is no more than 1%-3%. From the vegetables an average portion of spinach contains 19% and 2.6% of the tolerable daily amounts of Cd and Pb, respectively. For the other species of vegetables these figures are less than 5% for Cd (except for endive, 6.8%) and for lead less than 1%. Spinach contributes considerably to the need for Cu, Mn and Zn, in general more than 10% of the recommended daily amounts. The other species of vegetables contribute only from less than 1% to less than few percents.     

Characterization of limestones and their effects in vitro and in vivo in dairy cattle

Capacities of limestones of differing particle size to neutralize acid in vitro and to modify pH and utilization of feedstuffs in vivo were compared. Acid neutralization during pH-stat titrations was faster for fine than for coarse limestone, and mixed microbial cultures were more resistant to pH change when they contained fine calcium carbonate. Diets containing 25:75 corn silage to concentrates and .95% calcium from either coarse or fine limestone were fed to rumen-fistulated heifers. Total ruminal volatile fatty acid concentrations were higher for the fine limestone treatment. Ruminal volumes, dry matter disappearance, and ruminal fluid pH and dilution rate did not differ between fine and coarse limestone treatments. Ruminal fluid volume, osmolality, ratios of acetate to propionate, and concentrations of total volatile fatty acids were unaffected in rumen-fistulated Holstein cows fed 60:40 corn silage to concentrates and either .5% calcium (control) or 1.0% calcium from either coarse or fine limestone. Ruminal pH increased .07 to .10 units with limestone supplementation. Ruminal fluid dilution and particulate turnover rates were slower for the coarse limestone than the control treatment. Differences between coarse and fine limestones in vitro were observed under some conditions in vivo, but they were not consistent.     

Zinc and iron contents and their bioaccessibility in cereals and pulses consumed in India

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.