High reproducibility Abstract A novel method for the quantitation of 10 commonly prescribed benzodiazepines and/or their metabolites in meconium was developed using enzymatic hydrolysis, Dispersive Pipette XTRaction (DPX) + SALLE, and LC-MS/MS analysis. DPX + SALLE combines Dispersive Pipette XTRaction and SALLE (Salting-out Assisted Liquid-Liquid Extraction) for a novel cleanup mechanism. XTR Tips contain Weak Anion Exchange (WAX) for cleanup and salt (S) necessary for SALLE. This methodology can remove matrix interferences in less than one minute. The method was evaluated for linearity, precision, extraction efficiency, and limits of detection and quantitation. To test the validity of our method, a blind study was done with a collaborative laboratory including 35 meconium patient samples tested for ten benzodiazepines and/...

HybridSPE® Extraction Nestorone® (NES) is a synthetic progestin being developed by Population Council and NICHD for female and male contraception. NES does not bind to the androgen or the estrogen receptor and may have less adverse effects than androgenic progestin commonly used for female contraception. NES was previously measured in serum by radioimmunoassay that has non specific interference leading to detectable NES levels in men when no NES was administered. This objective of this study was to develop and validate a highly sensitive LC MS/MS method for the detection of serum Nestorone levels for research and clinical purposes in men.   Protein Precipitation       Serum Sample + I.S. + ACN with 1% Formic AcidVortex & Centrifuge (for increased efficiency use Tip-on-Tip)Transfer supernatant Condit...

11-beta-methyl-19-nortestosterone (11β-MNT) is the active androgen derived from 11-beta-methyl nortestosterone dodecylcarbonate (11β-MNTDC). 11β-MNT is being developed as a candidate drug of male hormonal contraception. 11β-MNT like dimethandronlone (DMA) binds to both the androgen and progesterone receptor and may provide the suppression of spermatogenesis with one compound instead of two agents, testosterone and a progestin. The objective of this study was to develop and validate a highly sensitive LC-MS/MS method for the simultaneous detection of serum 11β-MNT and 11β-MNTDC levels for research and clinical purposes in men.   Protein Precipitation Serum Sample + I.S. + ACN Vortex & Centrifuge (for increased efficiency use Tip-on-Tip) Transfer supernatant CONDITION Aspirate and Dispense ...

Vitamin D is an essential prohormone that regulates calcium and phosphate homeostasis. Vitamin D deficiency is a growing problem, manifesting as calcium malabsorption, secondary hyperthyroidism, muscle weakness, and/or osteoporosis/osteomalacia. With an estimated 50% of the global population being deficient in vitamin D, the extent of clinical testing continues to rise, with an increased emphasis on accuracy. Vitamin D assessment is performed by quantitation of 25-hydroxyvitamin D in serum and/or plasma. 25-hydroxyvitamin D has two forms: 25-hydroxyvitamin D2 (25OHD2) from vitamin D2, a plant based supplement, and 25-hydroxy-vitamin D3 (25OHD3) from vitamin D3, which is produced in the skin as a result of photochemical reaction. Both 25OHD2 and 25OHD3 can be accurately and efficiently analyzed using LC-MS/MS. However, removal of the sample matrix is requ...

Cannabis is the most widely abused illicit drug in the US. Results from the 2013 National Survey on Drug Use and Health show that between 2007 and 2012 the rate of marijuana use rose from 5.8% to 7.3%. As use of marijuana increases, it becomes more prevalent in clinical and forensic case work, particularly in impaired driving cases. In 2007 the National Highway Traffic Safety Administration (NHTSA) reported that 8.6% of nighttime drivers tested positive for cannabinoids—a rate almost four times higher than those with blood alcohol levels equal to or above 0.8 g/L. Recent marijuana use is associated with a 2–6 fold increased crash risk, depending on dose, than when unimpaired. The LC-MS/MS method developed in this study minimizes required sample volume and provides sensitive quantitation of THC, 11-OH-THC and THC-COOH in whole blood...

A Rapid Sample Preparation for Quantitative Analysis of Cortisol in Saliva and Urine by LC-MS/MS Summary of MSACL 2015 Poster Presentation by: Daniel Zhou and Run-Zhang Shi, Clinical Chemistry and Immunology of Clinical Laboratories, Stanford Health Care Reduce manual sample preparation time For determining saliva and urine cortisol levels LC-MS/MS is the measurement method of choice with high sensitivity and specificity. However, the conventional LC-MS/MS approach requires lengthy manual sample preparation by liquid-liquid extraction [LLE] or solid phase extraction [SPE], and patient samples are processed in a batch mode. To shorten sample preparation time, Stanford investigated dispersive pipette XTRaction tips that contained weak anion exchange (WAX) sorbent and salt (S) necessary for SALLE (Salting-out Assisted ...