Table 1.

Comparison of quantitative results of normal and dry eye tear lipid extracts

Compound identification	Li+ adduct (m/z)	Normal eyea (mg μl−1)	Dry eyeb (mg μl−1)	Increase (%)
Free glycerol	99	9.6 × 10−4 ± 2.3 × 10−4	1.5 × 10−3 ± 2.7 × 10−4	56
Glycerylisoprene acetal	153	6.8 × 10−4 ± 2.7 × 10−4	1.7 × 10−3 ± 8.5 × 10−4	150
Glycerylisoprene acetal	287	7.5 × 10−4 ± 2.9 × 10−4	1.8 × 10−3 ± 9.2 × 10−4	140
Monopalmitin	337	7.4 × 10−4 ± 1.6 × 10−4	1.1 × 10−3 ± 2.0 × 10−4	49
Monostearin	365	1.6 × 10−3 ± 3.4 × 10−4	2.5 × 10−3 ± 2.5 × 10−4	56
Glycerylisoprene acetal	421	1.2 × 10−3 ± 3.7 × 10−4	2.9 × 10−3 ± 1.6 × 10−3	142
1,3-Dipalmitin (major)	575	1.4 × 10−4 ± 3.1 × 10−5	2.1 × 10−4 ± 2.3 × 10−5	50
1-Stearin-3-myristin (minor)
1-Myristin-2-stearin (minor)
1-Stearin-3-palmitin (major)	603	5.2 × 10−4 ± 9.5 × 10−5	7.3 × 10−4 ± 2.7 × 10−5	40
1,3-Distearin (major)	631	5.1 × 10−4 ± 9.0 × 10−5	7.2 × 10−4 ± 1.3 × 10−5	41
Tristearin (major)c	897	1.3 × 10−4 ± 5.5 × 10−5	1.8 × 10−4 ± 9.9 × 10−5	38
1-Arachidin-2-stearin-3-palmitin (minor)
Total		7.3 × 10−3 ± 7.1 × 10−4	1.4 × 10−2 ± 2.1 × 10−3	92

^aAverages and standard errors of the mean reported for normal eye results were derived from four different sets of composite rabbit tear samples, where each composite set was analyzed separately. Tear composite volumes were 12, 12, 7, and 7 μL.

^bDry eye results are the average and standard error of the mean of two different composite sets which were analyzed individually. Tear composite volumes were 6 and 7 μl.

^cReported value for the triglyceride tristearin is substantially above the method's limit of detection for triglycerides (i.e. 5.8 × 10⁻⁶ mg μl⁻¹).