【求助】最低检测限

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)

2倍基线噪音所代表的浓度。

一般都用的三倍啊，2倍是不是很久以前的规定。

最低浓度标样走10针，峰面积或者峰高的标准偏差的3倍代入回归公式，有时候不强制过原点截距为负可能算出来是负的...这个时候就是直接用的浓度的标准偏差的3倍，反正我是这么弄的....