SST Interferent Peak on Thermo Ultra
It had been observed in our clinical laboratory that specimens
acquired with a serum separator tube had an interferent
that eluted immediately in front of testosterone containing
the same
m/z
transition. The presence of this interferent
precluded baseline resolution and was very troublesome
when integrating low levels of testosterone. Initially, this
interferent was observed on the TSQ Quantum Ultra.
However, it was determined that by raising the
capillary temperature of the TSQ Quantum Ultra up to
350 °C this interferent disappears without diminishing the
testosterone response.
Figure 2: 200 ng/dL Testosterone standard with deuterated internal standard
Figure 3: The linear fit calibration curve for testosterone. The calibration
curve has R
2
values greater than 0.99, which indicate excellent linear fits
over the dynamic range of 11-2000 ng/dL for testosterone. The LOQ value is
11 ng/dL with LOD values approximately 3 times lower.
Figure 5: Testosterone sample injection with Interferent from Serum
separator Tube eliminated
Figure 4: Testosterone sample injection with Interferent present from Serum
separator Tube
TTST
TTST IS
TTST
TTST IS
1...,53,54,55,56,57,58,59,60,61,62 64,65,66,67,68,69,70,71,72,73,...374