Table 1

Method	NO/NO₂- Detection Limit*	Continuous or Discrete?	Direct Measure in Blood?	Lab Sample Prep Required?	Potential as rapid clinical diagnostic?
EPR	~10 nM [139]	Continuous	Yes	No	No
MRI	~1 mM [54]	Continuous	Yes	No	No
Griess Reaction	10 -1500 nM [63]	Discrete	No	Yes	No
Ozone-Chemiluminescence	1 nM [63]	Discrete	No	Yes	No
Ion-selective nitrite electrode	0.5-10 µM [70]	Continuous	Yes	No	Yes
Nitric oxide electrode	0.08-1 nM [55]	Continuous	Yes	No	Yes
HPLC	10 pM [68]	Discrete	No	Yes	No
Capillary Electrophoresis	60 nM [69]	Discrete	No	Yes	No
GC-MS	0.5 µM [28]	Discrete	No	Yes	No
Exhaled NO	0.5 ppb (~ 15 nM) [140]	Continuous	No	No	No
Exhaled breath condensate	~ 1 µM [61]	Continuous	No	No	No
Silver Medical instrument	< 10 nM [71]	Continuous	Yes	No	Yes

Table 1: Comparison of current NO and NO₂ - detection methods. *Detection limits are approximate since these can vary in practice.