0.3ml洗脱液是否能完全洗脱？

我是用左手，左手控制洗耳球不需要像右手那么大的灵活精确控制不过，也要看个人习惯吧，没所谓用左手或右手

气相的检出限是个难题呀

这里有个英文的，你看看硝基呋喃

不知道....

Monitoring of the residue of fosthiazate in water samples using solid-phase extraction coupled with gas chromatography/mass spectrometrySolid-phase extraction (SPE) coupled with gas chromatography/mass spectrometry (GC/MS) was used to determine the fosthiazate residue in water samples. The water samples were first filtered through cellulose filters (0.45 microm pore size). A 100 mL volume of filtered water, in which 1 mL of methanol has been added, was then passed through a pre-conditioned 3 cm C18 cartridge at a flow-rate of 1.5 mL/min. Elution was performed by 1 mL of methanol. The eluant was finally dried under reduced pressure for solvent evaporation. The volume was quantitatively adjusted to 0.5 mL with methanol. The analysis was carried out on GC/MS. The mass spectrometer was operated in selected ion monitoring (SIM) mode. According to mass spectrum of fosthiazate, three selected ions at m/z of 126, 195, 283, respectively, were monitored for identification and quantification. High sensitivity and selectivity were achieved by using this method. The limit of detection for fosthiazate in water samples was determined to be 56.4 ng/L. The linearity was demonstrated over a wide range of concentrations covering from 0.282 to 141 microg/L. The recoveries were more than 85.5% and the relative standard deviations for the overall procedure were less than 4.42%. The fosthiazate residue was detected in the water samples from a pool near cropland where fosthiazate was used. The results demonstrate the suitability of the SPE-GC/MS approach for the analysis of fosthiazate in water.

这个跟标准有关系

其实只要有合适的方法，什么兽药都能用酶标仪做，所以第一个问题意义不大；多残留用酶标做确实吃力，酶标的优点主要还是批量快速

白日做梦，用那玩意能做药残笑话吧

A liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous determination of disulfoton and five of its oxidative metabolites (disulfoton-sulfoxide, disulfoton-sulfone, demeton-S, demeton-S-sulfoxide and demeton-S-sulfone) in human whole blood and urine. Extraction was undertaken using a QuEChERS method, which is commonly used in food analysis. D10-Disulfoton was used as the internal standard. Separation was carried out using a CAPCELL-PAK MG II column (35×2.0 mm i.d., 5 μm, Shiseido) with a mobile phase of 10 m mol/L ammonium formate and methanol. This method was applied in an autopsy case, and disulfoton and its oxidative metabolites were successfully detected in both blood and urine. The concentrations of disulfoton in the blood and urine were 360 and 23.8 ng/mL, respectively. There was a relatively low concentration of demeton-S in both the blood (4.0 ng/mL) and urine (45.7 ng/mL). To date, there have been no reported cases of detection of demeton-S in human samples.

不错，以后类似的考试可以选些题目。

我们用LC-MS-MS

AB公司的产品质量确实是好，但调研中发现其维护保养等运行费用也很高，对于我们每年只检测一两百个样品（5年后可能会达到1000个）的小机构，负担可能过重

0.5ppb的回收率稍微低了点，1-10ppb的回收率不错，都在允许范围之内

积极参与啊

不确定度不难，有固定的模式，如果是国家级实验室，每个方法均要有一个不确定度的

我们用LCMS检测的。

国家，行业，地方，企业

蔬菜样品用料理机破碎了，取样时混匀再称取25g，平行样取时没差别。

过氨基二合一的柱子试一试看？