Liquid chromatography—mass spectrometry with on-line solid-phase extraction by a restricted-access C18 precolumn for direct plasma and urine injection

Restricted access materials and large particle supports for on-line sample preparation: an attractive approach for biological fluids analysis

“…The ADS column can tolerate up to 80-100 ml of plasma [50,53,54]. The LiChrospher ADS-RP was able to achieve the direct analysis of pharmaceutical compounds in several biological matrices such as plasma [49,50,53,[55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73], serum [42,43,[74][75][76][77][78][79], urine [60,75,76,78,80], microdialysate [81,82], saliva [64], liver homogenate [49], intestinal aspirates [76], cell cultures [68,83], bronchial secretions [74], milk [84] and tissue [67].…”

Possibilities to improve automation, speed and precision of proteome analysis: A comparison of two-dimensional electrophoresis and alternatives

“…The values are worse for proteins; with numbers ranging from 0.1 to 1 mg/mL, corresponding to 10 -9 -10 -8 mol/L concentrations [140]. Note that enrichment factors of approximately 1000 are possible if a sample preconcentration (e.g., SPE) step after PIEF is employed [140][141][142]. An LOD in the low femtomole range can be obtained with nanoflow LC-MS instruments [23], while a low picomole range has been obtained for peptides (0.5-7 kDa) using a special SEC microcolumn (30 cm6300 mm ID, 2 mL/min flow rate hyphenated to a mass spectrometer.…”

Quantitative Determination Method for Trace Amount of Penicillin Contaminants in Commercially Available Drug Product by HPLC Coupled with Tandem Mass Spectrometry

“…However, such approaches did not work adequately for the recovery of the penicillins from the matrix containing Micafungin (poor recovery rate up to 40%, data not shown), and careful attention was required to handle a trace amount of the penicillins during the extraction procedure. To improve the accuracy of the method without extraordinary handling, an on-line extraction was examined using the column switching technique, [11][12][13][14] which enables reduction of the loss of analytes during the extraction procedure. Figure 3 shows diagrams of an HPLC equipped with a valve for the column switching technique.…”