High-performance liquid chromatographic method for the determination of occupational exposure to the pesticide abamectin

As part of a survey of occupational exposure to pesticides in greenhouses for growing ornamentals, analytical methods were developed and validated for the measurement of exposure of workers to the pesticide abamectin. Abamectin consists of a mixture of avermectin-B1a and avermectin-B1b, which are members of a class of fermentation products of the soil microorganism Streptomyces Avermitilis. Because of the high molecular weight of the avermectins (greater than 800 daltons), high-performance liquid chromatography (HPLC) was the analytical method of choice. Previously described HPLC methods that used fluorescence detection were adapted and validated for the determination of dermal exposure by the analysis of cotton gloves and foliar dislodgeable residue. IOM samplers (developed at the Institute of Occupational Medicine, Edinburgh, U.K.) for collecting the inspirable fraction of dust or aerosols were tested for the determination of airborne abamectin concentrations in greenhouses. An analytical procedure considerably simpler than published methods appeared suitable for the determination of abamectin residues on cotton gloves and on greenhouse foliage. Analytical recovery from cotton gloves, solutions of foliar dislodgeable residues, and air-sampling filters was essentially complete. However, air concentrations of abamectin could not be reliably measured by using the IOM sampling device because of breakdown during sampling. Between-day coefficients of variation for solutions of dislodgeable residue and cotton glove extracts were between 3% and 6% for abamectin concentrations between 5 and 140 micrograms/L.     

High-performance liquid chromatographic determination of vitamin D3 in bovine colostrum, early and later milk

A simplified and accurate method for determination of naturally occurring vitamin D3 in bovine milk was established by high-performance liquid chromatography (HPLC) using successively reversed-phase and straight-phase columns. Exactly 25.0 ml of a sample of bovine milk was taken and the lipid was extracted with a solvent mixture of petroleum ether and ethyl ether (1:1) with small amounts of ethanol and Triton X-100, present. The extracted lipid was subjected to the first preparative HPLC using a Nucleosil 5C18 column (reversed-phase type) with acetonitrile-methanol (1:1) as the mobile phase, and a fraction containing vitamin D3 was isolated. The fraction was subsequently subjected to the second analytical HPLC using a Zorbax SIL column (straight-phase type) with 0.4% isopropanol in n-hexane as the mobile phase. Vitamin D3 was assayed by estimating the peak height on the chromatogram. The overall recovery and CV values were 92.1 +/- 8.7% and 9.4%, respectively, which were satisfactory. The proposed method was applied to several kinds of colostrum, early and later bovine milk in pairs. The assayed values in the colostrum of the group with large amounts of vitamin D3 administered before delivery to prevent parturient paresis were higher than those in the group with no administration. However, the values of the former group generally decreased in the respective early and later milk in step and there were few differences among those in the later milk of the two groups. The assayed values in later milk were 30-80 IU/liter.     

High-performance liquid chromatographic determination of vitamin D3 in fish liver oils and eel body oils

Identification and determination of vitamin D3 (or D2) and 25-OH-D3 in fish liver oils and eel body oils were carried out. By co-chromatography on HPLC, UV spectra and/or GC-MS, vitamin D3 was identified in naturally occurring fish liver oils and eel body oils, whereas a drop of fish liver oil contained supplemented vitamin D2. 25-OH-D3 was identified only in skipjack liver oil. The HPLC method proposed in a previous report (Takeuchi, A. et al. (1984): J. Nutr. Sci. Vitaminol., 30, 11-25) was confirmed to also be useful for determination of vitamin D3 (or D2) in fish liver oils and eel body oils. The assayed values of vitamin D3 in skipjack and tuna liver oils were 57,760 and 16,200 IU/g, respectively, which were much higher than those in cod and pollack liver oils. The assayed values of vitamin D3 in eel body oils were very low (16-43 IU/g) and showed no appreciable change despite differences in the farming conditions. Determination of 25-OH-D3 in skipjack oil was performed by using HPLC, and the assayed value was 1.8 micrograms/g. This was about 1/800 lower than that of vitamin D3.     

串珠镰刀菌素的薄层及高效液相色谱测定法

建立了玉米、稻谷中串珠镰刀菌素的薄层和高效液相色谱测定方法。样品用水－乙腈（５：９５Ｖ／Ｖ）提取，正己烷脱脂后用ＰＴ－Ｃ１８色谱预处理柱净化，经０．４５μｍ滤膜过滤后供高效液相色谱分析；薄层色谱分析可省略掉ＰＴ－Ｃ１８柱净化步骤。两种方法的最低检出量依次为５ｎｇ和１００ｎｇ。在玉米、稻谷样品中各加入０．２～２０μｇ／２０ｇ串珠镰刀菌素时，其不同水平的平均回收率为：７６％～８１％（薄层色谱法）和７５．２％～１０３．６％（高效液相色谱法）。     

High-performance liquid chromatographic determination of vitamin D in foods, feeds and pharmaceuticals by successive use of reversed-phase and straight-phase columns

A simplified and accurate method for the determination of vitamin D in foods, feeds and pharmaceuticals was established by high-performance liquid chromatography (HPLC) using successively reversed-phase and straight-phase columns. About 1-2 g of a sample was accurately weighed and directly saponified. The extracted unsaponifiable matter was subjected to preparative HPLC using a reversed-phase column and a vitamin D fraction was collected. The fraction was subsequently subjected to analytical HPLC using a straight-phase column and vitamin D was assayed by estimating the peak height. The proposed method was applied to various kinds of samples, e.g., fishery products, fish meals, mixed feeds for fish farming and chicken farming, egg yolk, milk products, cattle liver, Shiitake, fortified foods and multivitamin preparations. The results showed that the proposed method was useful for the determination of vitamin D in such samples, because the peak of vitamin D in the profile of the second HPLC was always clearly separated from other concomitants and good recovery was obtained. Therefore, we think that the method is useful as a routine one for the determination of vitamin D in foods, feeds and pharmaceuticals.     

工作场所空气中百草枯的高效液相色谱测定法

目的 建立工作场所空气中百草枯的高效液相色谱测定方法.方法 用聚四氟乙烯滤膜采集工作场所空气中百草枯,用去离子水洗脱后高效液相色谱(紫外检测器)测定.结果 方法的线性范围为0～30.0 μg/ml;回归方程y=47x-22.8,相关系数r=0.999 3;最低检出浓度为0.056 mg/m3(以采集45 L空气样品计);3种不同浓度的批内、批间精密度分别为2.5%、1.3%、0.9%和3.4%、3.7%、3.5%;回收率为97.5%～102.5%;洗脱效率为97.3%～99.7%;采样效率为100%;样品在室温下至少可保存7 d.结论 方法的各项指标均符合GBZ/T 210.4-2008<职业卫生标准制订指南第4部分:工作场所空气中化学物质测定方法>,可用于工作场所空气中百草枯的测定.     

反相HPLC法同时测定饮料中的两种人造甜味剂

应用反相HPLC法，探讨了同一色谱条件下，食品中安赛蜜，糖精钠、咖啡因及苯甲酸的分离条件，并在此基础上建立了饮料中人造甜味剂安赛蜜、糖精钠的测定方法，取得了满意的结果。在反相C_(18)柱上，使用甲醇-冰乙酸-水（20+3.5+76.5）为流动相，可使安赛蜜、糖精钠、咖啡因，苯甲酸快速而良好地分离，254nm波长下检测，安赛蜜的线性范围为0.002～1.00g／L，最小检测量为0.04μg；糖精钠的线性范围为0.005～1.00g／L，最小检测量为0.08μg，在饮料分析中，外标单点校正法测得数据再用标准添加法处理进而求出的回收率分别为安赛蜜97.6％（n=5,CV=0.74%)、103.5%（n=5，CV=1.l%）、95.l%（n=5，CV=0.73%）；糖精钠97.9%（n=5，CV=0.66％）、99.9%（n=5，CV=0.73%)、102.1％（n=5，CV=0.18%）。本方法分析步骤简便，且检测波长适用于国产单波长检测器。     

工作场所空气中尿素的高效液相色谱检测法

目的 建立工作场所空气中尿素的高效液相色谱检测法.方法 以纯水为流动相,流速0.95 ml/min,选用C18色谱柱,检测波长190 nm,高效液相色谱法测定.结果 尿素在0～300μg/ml范围内线性关系良好,相关系数为0.9996,方法检出限为0.4 μg/ml,低、中、高浓度尿素溶液精密度分别为3.1%、2.5%和3.7%.以玻璃纤维滤膜为采样滤料,采样效率为93.0%～98.0%.采集样品存放于具塞比色管中,可保存7 d以上.结论 该方法操作简便,精密度和灵敏度较高,可以满足工作场所空气中尿素的测定.