【讨论】关于检出限的困惑？（有点想得越多越糊涂）

楼主做的是什么元素呀？空白值怎么这么高呀？标准曲线的浓度怎么是mg/L，数值是多少呀？

回楼上：做锡的测定。
标准系列：0、0.01、0.02、0.04、0.06、0.08mg/L。
就是想搞明白，检出限的具体计算过程。
仪器说明书上也没写的太清楚。

这样的话你的检出限计算结果应该是0.0010mg/L吧。

如果按照所述的方法，结果应该没有单位阿？好像有问题！

有点糊涂啊，到底怎么计算的了......

3楼的检出限是对的，0.001mg/L。
仪器默认标准单位都是ug/L，你输入的是标准系列：0、0.01、0.02、0.04、0.06、0.08mg/L，仪器认为是ug/L。差了1000倍。

你如果是要做仪器空白,就可以用载流空白来做,如果你想做这种方法对于某种介质的空白,一定要用样品空白来做.

对于LoD和LoQ的计算,有好几种不同的方法,每个方法都有自己的优缺点,下面给你一些方法可以参考,但是计算出LoD和LoQ后,最好是将这个浓度验证一下,一般来说RSD达到17.7%就可以了.

LoD and LoQ could be assessed by different approaches. From the following procedures, choose the one which is the most appropriate to the method to be validated:

1)    LoD and LoQ estimation by signal/noise ratio procedure (chromatographic and spectroscopic methods):

Parameter    Minimum requirement
Samples:    Spike one blank sample at 3 low concentration levels close to the expected LoD and LoQ (at least 3 concentration levels)
Number of replicates:    Analyze each spiked sample 3 times

2)    LoD and LoQ by standard deviation of the blank (gravimetric, photometric, enzymatic, titrimetric methods):

Parameter    Minimum requirement
Samples:    1 blank sample (or 1 sample with a low amount of analyte)
Number of replicates:    At least 6 replicates

3)    LoQ by target performance characteristics (precision and/or recovery):

Parameter    Minimum requirement
Samples:    Spike one blank sample at low concentration levels close to the expected LoQ (at least 3 concentration levels)
Number of replicates:    Analyze each spiked sample at least 3 times.

4)    LoQ corresponding to the lowest calibration point (lowest validated level)

一个完整的Method Validaiton除了LoD和LoQ之外,还需要很多的步骤.

不是很清楚哦

俺也糊涂了