A Statistical Estimation Approach for Quantitative Concentrations of Compounds Lacking Authentic Standards/Surrogates Based on Linear Correlations between Directly Measured Detector Responses and Carbon Number of Different Functional Groups

Table 4

Results of replicate calibration of 19 reference VOCs based on ST/TD approach used in this study: (1) response factor (RF), (2) determination of coefficient (𝑅²), and (3) relative standard error (RSE, %).

Order	VOC group	Compound	Actual RF				𝑅^2			RSE^b  (%)
			1st	2nd	Mean	CV^a	1st	2nd	Mean
1	Aldehyde	AA	522	497	510	3.47	0.9619	0.9698	0.9659	2.52
2		PA	12,017	11,950	11,984	0.40	0.9991	0.9991	0.9991	3.49
3		BA	43,572	43,467	43,520	0.17	0.9963	0.9938	0.9951	1.05
4		IA	66,125	65,836	65,981	0.31	0.9962	0.9932	0.9947	1.93
5		VA	59,322	59,804	59,563	0.57	0.9973	0.9973	0.9973	1.35
6	Aromatic	B	131,760	131,280	131,520	0.26	0.9909	0.9930	0.9920	2.06
7		T	168,602	165,819	167,211	1.18	0.9995	0.9995	0.9995	0.83
8		S	188,198	191,709	189,954	1.31	0.9995	0.9997	0.9996	1.32
9		p-X	188,510	184,038	186,274	1.70	0.9997	0.9987	0.9992	0.49
10		m-X	197,068	193,888	195,478	1.15	0.9992	0.9994	0.9993	0.56
11		o-X	198,376	194,140	196,258	1.53	0.9991	0.9991	0.9991	0.73
12	Carboxylic	PPA	26,574	25,963	26,269	1.64	0.9977	0.9953	0.9965	1.68
13		BTA	71,259	67,832	69,546	3.48	0.9963	0.9967	0.9965	0.13
14		IVA	99,441	94,589	97,015	3.54	0.9965	0.9935	0.9950	2.09
15		VLA	79,615	78,949	79,282	0.59	0.9918	0.9925	0.9922	0.97
16	Ketone	MEK	48,980	48,566	48,773	0.60	0.9969	0.9987	0.9978	1.79
17		MIBK	117,383	117,646	117,515	0.16	0.9998	0.9985	0.9992	0.85
18	Alcohol	i-BuAl	93,667	92,778	93,223	0.67	0.9969	0.9972	0.9971	1.73
19	Ester	BuAc	121,114	117,791	119,453	1.97	0.9982	0.9973	0.9978	0.79
	Mean					1.30	0.9954	0.9954	0.9954	1.39
	SD					1.12	0.0085	0.0067	0.0075	0.82

aCV (coefficient of variation) = SD/mean * 100.
^b1 μL injection of 4th calibration point (mean 21.6 ng μL⁻¹ F-WS) for five replicate analyses.