Table 3 Back-calculated accuracy and precision of standard solutions and plasma sample at three spiking levels.

From: Evolution of Energy Related Metabolites in Plasma from Newborns with Hypoxic-Ischemic Encephalopathy during Hypothermia Treatment

Analyte

Standard solutions - % Accuracy ± s (conc µmol L−1)

Spiked plasma samples - % Accuracy ± s (conc µmol L−1)

Intra-day (N = 3)

Inter-day (N = 3)

Intra-day (N = 3)

Inter-day (N = 3)

Low

Medium

High

Low

Medium

High

Low

Medium

High

Low

Medium

High

Pyruvate

94 ± 20 (0.8)

109 ± 1 (25)

96.8 ± 0.1 (100)

90 ± 6 (0.8)

105 ± 4 (25)

96 ± 3 (100)

92 ± 10 (20)

92 ± 4 (40)

85.0 ± 1.0 (50)

94 ± 7 (20)

97 ± 5 (40)

89 ± 3 (50)

Lactate

115 ± 18 (3.9)

93 ± 7 (250)

97 ± 11 (1000)

114 ± 3 (3.9)

96 ± 3 (250)

99 ± 4 (1000)

69 ± 10 (250)

96 ± 14 (50)*

95 ± 5 (100)*

83 ± 14 (250)

120 ± 30 (50)*

100 ± 30 (100)*

Acetoacetate

108 ± 7 (3.1)

96 ± 4 (25)

100.9 ± 1.8 (100)

107.3 ± 0.5 (3.1)

102 ± 8 (25)

100.2 ± 1.6 (100)

70 ± 50 (10)

72 ± 18 (20)

69 ± 7 (50)

90 ± 20 (10)

68 ± 18 (20)

71 ± 14 (50)

β-hydroxybutyrate

112.6 ± 1.8 (0.4)

103 ± 6 (25)

97.3 ± 3.8 (100)

103 ± 9 (0.4)

104 ± 3 (25)

97.8 ± 0.4 (100)

65 ± 17 (10)

69 ± 3 (20)

63 ± 3 (50)

77 ± 12 (10)

80 ± 30 (20)

74 ± 13 (50)

Succinate

119 ± 12 (0.1)

100 ± 2 (6.3)

97.9 ± 0.8 (25)

118 ± 9 (0.1)

102 ± 4 (6.3)

97.2 ± 0.6 (25)

85 ± 10 (2)

93 ± 7 (4)

87.0 ± 0.8 (10)

99 ± 16 (2)

110 ± 20 (4)

95 ± 11 (10)

Fumarate

96 ± 2 (0.1)

87 ± 2 (6.3)

105.9 ± 0.9 (25)

103 ± 6 (0.1)

95 ± 7 (6.3)

102 ± 3 (25)

74 ± 8 (2)

80 ± 6 (4)

62.00 ± 0.17 (10)

80 ± 30 (2)

100 ± 30 (4)

80 ± 30 (10)

Malate

94 ± 3 (0.1)

87 ± 2 (6.3)

104.5 ± 0.7 (25)

109 ± 13 (0.1)

94 ± 7 (6.3)

103 ± 3 (25)

82 ± 11 (2)

87 ± 7 (4)

97.0 ± 0.5 (10)

94 ± 17 (2)

100 ± 30 (4)

103 ± 17 (10)

α-ketoglutarate

93 ± 16 (0.1)

105 ± 3 (6.3)

96.5 ± 1.1 (25)

100 ± 7 (0.1)

107.6 ± 1.7 (6.3)

99 ± 2 (25)

97 ± 11 (2)

103 ± 9 (4)

98.0 ± 0.9 (10)

111 ± 12 (2)

111 ± 10 (4)

114 ± 17 (10)

  1. Note: Values within brackets indicate the concentration of each metabolite in the standard solution/spiking concentration.
  2. *Measured in 1:10 diluted sample.