畜禽场周边土壤和水中环丙氨嗪和三聚氰胺污染情况调查

通过现场采样,采集到上海、广东以及江苏10家畜禽场周边199份环境样本,并利用超高效液相色谱-串联质谱对采集到的土壤样品和水样中的环丙氨嗪和三聚氰胺残留量进行分析。分析结果表明,畜禽场周围环境中存在一定程度的三聚氰胺污染,环丙氨嗪的污染情况则相对较轻;随着土层的加深,土层中三聚氰胺残留呈下降趋势。经调查,三聚氰胺和环丙氨嗪在环境中的分布与环丙氨嗪在畜禽场的使用形式和周期密切相关;污染情况还存在地域差别,江苏省和上海市畜禽场周围的三聚氰胺污染情况较广东省严重。     

高效液相色谱法测定土壤中的二氯喹啉酸

用50 ml甲醇︰0.05 mol/L硼砂溶液(p H=10)(9︰1,v/v)作为提取剂对20 g(或适量)土壤样品中残留的二氯喹啉酸振荡提取2 h,离心过滤后分取滤液25 ml浓缩,甲醇定容至2 ml,再用滤膜过滤后待测定;高效液相色谱仪(HPLC)以1.0 ml/min的甲醇︰1%乙酸水溶液(55︰45,V/V)为流动相,柱温45℃,在238 nm的紫外光波长下进行二氯喹啉酸的外标法定量。该方法精密度为6.0%,检出限为0.012 mg/kg,不同类型土壤的加标回收率74.9%~98.8%,能满足有机分析要求。该方法既简捷易操作,又能满足土壤中二氯喹啉酸低残留量的测定。     

高效液相色谱法测定土壤中均三氮苯类除草剂

采用高效液相色谱法测定土壤中7种均三氮苯类除草剂:西玛津、阿特拉津、扑灭通、莠灭净、扑灭津、扑草净、去草净。用乙腈或甲醇:乙腈(3:7v/v)在索氏提取器上提取土壤中的7种均三氮苯类除草剂,提取液经旋转蒸发,氮吹浓缩,中性氧化铝小柱净化,再次氮吹浓缩后,高效液相色谱二极管阵列检测器检测,外标法定量,检测波长为224nm。实验结果表明该方法的变异系数在1.24%～6.83%之间,平均回收率在95.0%～106.9%之间,检出限为0.84～2.07μg/kg。该方法是分析土壤中均三氮苯类除草剂农药的一种较为理想的方法。     

土壤中土霉素残留的高效液相色谱检测方法

为有效测定土壤中土霉素残留量,建立了固相萃取－高效液相色谱法提取以及测定潮土、红壤、紫色土中土霉素残留量的方法。土壤中土霉素残留经提取缓冲溶液进行有效提取,经过DVB固相萃取小柱纯化、无水甲醇洗脱和氮气流浓缩后,经HPLC测定。对提取缓冲液、流动相以及流动相pH值、有机相与无机相的比例以及流速等测定条件进行优化研究。结果表明：提取液为Na2EDTA-Mcllvaine,流动相为乙腈∶0.01mol/L磷酸二氢钠（pH值2.5,V∶V=10∶90）,温度25℃,流速1.2ml/min,检测波长350nm对3种不同性质的土壤中土霉素残留量的测定最为合适。应用本方法进行土壤中土霉素残留量的测定,土霉素含量与峰面积具有良好的线性关系,相关系数（n=9）分别为红壤0.997,紫色土0.995,潮土0.987;检出限分别为红壤0.11mg/kg,紫色土0.17mg/kg,潮土0.09mg/kg;回收率(n=18)分别为红壤80.7%~128.8%,紫色土70.5%~100.0%,潮土61.5%~103.9%;相对标准偏差(RSD, n=18)分别为红壤7.1%~28.2%,紫色土11.9%~38.1%,潮土4.1%~17.0％。本方法简便、准确,适合于测定不同土壤中土霉素残留量,结果可靠。     

高效液相色谱法测定土壤中化学武器降解产物二苯砷酸

二苯氰砷(diphenylcyanoarsine)和二苯氯砷(di-phenylchloroarsine)是一战和二战期间被大量制造和使用的一类呕吐剂和糜烂剂,在日制化学武器系统中俗称"红弹"。战后,大量化学武器被遗弃于中国、欧洲和日本,且大部分通过海洋倾倒和陆地填埋方     

反相高效液相色谱法检测水,土壤中的除草醚

介绍了应用反相高效液相色谱检测水，土壤中除草醚的方法。该方法对除草醚在水和土壤中的回收率分别为９９．０％和９２．５％，最小检出浓度分别为１．１×１０＾－２ｍｇ／Ｌ和０．１１ｍｇ／ｋｇ。     

高压液相色谱法同时测定植物组织中六种细胞分裂素组分和生长素

利用高效液相色谱研究了植物组织中六种细胞分裂素组分和生长素含量的测定方法。结果表明,采用反相色谱柱Hibar.RT250-4.6,在45℃恒温下以甲醇1%乙酸(40/60,v/v)溶液为流动相0、.6.mL/min等度洗脱,在=269.nm处能准确检测出植物组织中六种内源细胞分裂素组分和生长素的含量,检测限低至0.001.mg/L。本研究对样品的提取和纯化过程也做了改进,排除了杂质和色素对样品的干扰,为研究植物体内源激素对环境响应特征提供了有效的测定方法。     

高效液相色谱法和分光光度法测定水溶肥料中壳聚糖含量的方法比较

建立了高效液相色谱法和分光光度法测定水溶肥料中壳聚糖含量的不同分析方法,对壳聚糖的水解条件进行了系统的考究.结果表明,以1+1的盐酸溶液,温度100℃,时间24 h水解效果最佳.以1-苯基-3-甲基-5-吡唑啉酮(PMP)作为衍生剂的高效液相色谱法的线性范围、检出限和加标回收率分别为1～200 mg/L、0.07 mg...     

The simultaneous determination of muramic acid and glucosamine in soil by high-performance liquid chromatography with precolumn fluorescence derivatization

Summary The optimal release and quantitative estimation of muramic acid and glucosamine were studied simultaneously in soil samples. The effect of hydrolysis conditions, HCl concentration, hydrolysis time, the ratio of soil dry weight to acid, and the recovery of reference substances were investigated. Derivatization of the fluorogenic reagent o-phthalaldehyde, in the presence of 2-mercaptoethanol with the residue of a soil hydrolysate, was achieved by optimizing the relative amounts of o-phthalaldehyde to hydrolysate in the reaction mixture, the pH of both, and the incubation period. A linear relationship was found between the fluorescence response and the concentration of the test substances. The muramic acid, as well as the glucosamine (o-phthalaldehyde) derivatives gave single peaks, and complete separation from interfering substances at the picomol level was achieved in a short time (3 h preparation and 30 min for chromatography) by using high-performance liquid chromatography.     

Analytical method for the determination of cyromazine and melamine residues in soil using LC-UV and GC-MSD

A method is reported for the determination of cyromazine and melamine residues in soil. Soil samples are extracted twice via mechanical shaking, each time with 70% acetonitrile/30% 0.050 M ammomium carbonate for 30 min. An aliquot portion of the pooled extracts is subjected to strong cation exchange (SCX) purification on AG 50W-X4 resin. Final analysis is accomplished using liquid chromatography-ultraviolet (LC-UV) detection at a wavelength of 214 nm. Confirmatory analyses can be performed using gas chromatography-mass selective detection (GC-MSD) in the selected ion monitoring (SIM) mode. The limit of detection (LOD) is 2.5 ng injected and the limit of quantification (LOQ) is 10 ppb when using LC-UV for the analysis of N-cyclopropyl-1,3,5-triazine-2,4, 6-triamine (cyromazine) and 1,3,5-triazine-2,4,6-triamine (melamine). The LOD is 0.050 ng injected and the LOQ is 10 ppb when using GC-MSD for confirmatory analyses. The mean procedural recoveries were 97 and 95% and the standard deviations were 16 and 11% for cyromazine and melamine, respectively (n = 24), when using LC-UV. The mean procedural recoveries were 107 and 92% and the standard deviations were 9.9 and 16% for cyromazine and melamine, respectively (n = 29), when using GC-MSD. The method validation study was conducted under U.S. EPA FIFRA Good Laboratory Practice Guidelines 40 CFR 160. The method also passed an Independent Laboratory Validation (ILV) as per U.S. EPA FIFRA Subdivision N.     

Tillage and residue management effects on β-glucosaminidase activity in soils

There is an increasing interest in assessing the effects of tillage systems and residue management on biochemical processes, especially enzyme activities, of soils. This study was carried out to investigate the effects of three tillage systems (no-till, chisel plow and moldboard plow) and four residue placements (bare, normal, mulch and double mulch) on the activity of N-acetyl-β-glucosaminidase (NAGase, EC 3.2.1.30) involved in C and N cycling in soils. The activity values were significantly affected by tillage and residue management practices, being greatest in soils with no-till/double mulch and least with no-till/bare and moldboard/normal. Also, they were the highest under no-till/ double mulch-treated soils. Linear regression analyses showed that the activity of NAGase was significantly correlated with organic C in the surface soils (r=0.89***) and with organic C content at different depths (r=0.97***). The NAGase activity values were significantly correlated with the arylamidase activity values of the soils (r=0.63**), suggesting that tillage and residue management practices have similar impacts on the activities of these enzymes. The activity of this enzyme decreased markedly with increasing depth of the surface soil (0-15 cm) of the no-till/ double mulch-treated plots.     

Impact of residue characteristics on phosphorus availability in West African moist savanna soils

The role of residue characteristics in enhancing the availability of P was investigated in a greenhouse study using two soils from the northern Guinea savanna (NGS) and four from the derived savanna (DS) zones of the West African moist savanna. Eight organic residues of varying C-to-P ratio were used and maize ( Zea mays) was grown for 7 weeks. The effect of the organic residues on P availability (measured as resin P and maize P accumulation) differed among the soils. On average, the increase in resin P, calculated as {[(soil+residue)–control]/(control)×100}, was between 8% (Davié, DS) and 355% (Danayamaka, NGS). Maize P accumulation was increased by ca. 11% in Davié and Niaouli (DS) soils and 600% in Danayamaka soil. The increase in maize total dry matter yield (DMY) ranged from 2% to 649%. Residues with C-to-P ratio >200 produced lower DMY than those with lower ratios. Residue organic P (Po) extractable with 0.2 N H₂SO₄ (acid-Po) accounted for 92% ( P =0.0001) of the variation in DMY in a step-wise regression with residue parameters as independent variables and mean DMY as the dependent variable. The residue Po extractable with 0.5 M NaHCO₃ (HCO₃-Po) correlated significantly with DMY in Danayamaka and Davié soils, and with P accumulation in Danayamaka soil. The relationships between the residue Po and DMY might imply that Po fractions in decomposing residues contribute to P availability. However, the suitability of using the Po content of organic residues to predict their agronomic value with respect to P nutrition needs further evaluation.     

滇池周边大棚土壤中六六六和滴滴涕残留特征

采用气相色谱(ECD)对滇池周边不同年限大棚土壤中六六六(HCHs)和滴滴涕(DDTs)残留量进行了测定, 探讨其残留分布特征。结果表明: (1)大棚种植年限对土壤中残留量影响显著, 种植年限长于10 年的大棚土壤中HCHs 和DDTs 的残留量显著高于年限短于10 年的大棚, DDTs 是有机氯农药(OCPs)的主要组成成分;短于10 年的大棚间, 土壤中HCHs 和DDTs 残留量差异不显著。(2)不同土层中, HCHs 残留量在土壤剖面上的变化趋势不明显, 而DDTs 在表层土壤(0~20 cm)中残留量显著高于下层。(3)从HCHs 和DDTs 的同系物组成来看, HCHs 以β-HCH 残留量最高, 部分样点中p,p′-DDT/(DDD+DDE)比值大于1。可判断HCHs 残留主要是过去施用的残留物, 而DDTs 仍有新的污染输入, 有待进一步调查研究。     

Determination of anthocyanidins in berries and red wine by high-performance liquid chromatography

A high-performance liquid chromatographic (HPLC) method for the determination of anthocyanidins from berries and red wine is described. Delphinidin, cyanidin, petunidin, pelargonidin, peonidin, and malvidin contents of bilberry (Vaccinium myrtillus), black currant (Ribes nigrum), strawberry (Fragaria ananassa cv. Jonsok), and a Cabernet sauvignon (Vitis vinifera) red wine were determined. The aglycon forms of the anthocyanins present in the samples were revealed by acid hydrolysis. A reversed phase analytical column was employed to separate the anthocyanidins before identification by diode array detection. The suitability of the method was tested by determining the recovery (95-102% as aglycons and 69-104% from glycosides) for each anthocyanidin. Method repeatability was tested by charting the total aglycon content of two samples over a period of 14 analyses and determining the coefficients of variation (1.41% for bilberry and 2.56% for in-house reference material). The method developed proved thus to be effective for reliable determination of anthocyanidins from freeze-dried berry samples and red wine. The total anthocyanidin content of the tested samples was as follows: in-house reference material, 447 +/- 8 mg/100 g; strawberry, 23.8 +/- 0.4 mg/100 g; black currant, 135 +/- 3 mg/100 g; bilberry, 360 +/- 3 mg/100 g; and Cabernet sauvignon red wine, 26.1 +/- 0.1 mg/100 mL.     

Determination of deltamethrin in cattle dipping baths by high-performance liquid chromatography

Deltamethrin (S)-alpha-cyano-3-phenoxybenzyl) (1R,3R)-3-(2, 2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylate is classified as a pyrethroid pesticide that is largely used as an acaricide and scabicide. For bovines, especially, the treatment is done with the aid of dipping baths of the pyrethroid solution. Analytical control of the concentration of deltamethrin in these baths must be done periodically in order to guarantee treatment efficacy. In the proposed procedure, the sample is prepared by centrifugation followed by filtration and measurement by high-performance liquid chromatography (HPLC) with spectrophotometric detection at 275 nm. Separation is done in a Nucleosil C-18 column with acetonitrile-water as the mobile phase. A calibration curve was constructed with external standards, and a detection limit of 0.2 mg L(-)(1) was obtained. In the samples analyzed, only ca. 20% of the total deltamethrin content was found in the solution. The results obtained demonstrate the potential of the described procedure for the determination of deltamethrin in animal baths.     

Determination of seven organosulfur compounds in garlic by high-performance liquid chromatography

The properties of garlic (Allium sativum L.) are attributed to organosulfur compounds. Although these compounds change during cultivation and storage, there is no report of their simultaneous analysis. Here, a newly developed analytical method with a rapid and simple sample preparation to determine four sulfoxides and three gamma-glutamyl peptides in garlic is reported. All garlic samples were simply extracted with 90% methanol solution containing 0.01 N hydrochloric acid and prepared for analysis. Alliin, isoalliin, methiin, cycloalliin, and gamma-l-glutamyl-S-methyl-l-cysteine were determined by normal-phase HPLC using an aminopropyl-bonded column. gamma-l-Glutamyl-S-(2-propenyl)-l-cysteine and gamma-l-glutamyl-S-(trans-1-propenyl)-l-cysteine were separated on an octadecylsilane column. The overall recoveries were 97.1-102.3%, and the relative standard deviation values of intra- and interday precision were lower than 2.6 and 4.6%, respectively. This newly developed method offers some advantages over the currently accepted techniques including specificity, speed, and ease of use and would be useful for chemical and biological studies of garlic and its preparations.