Detecting Pharmaceuticals in the Red Blood Cell Inventory of a Hospital Blood Bank.

We tested 220 red blood cell units for the presence of pharmaceuticals; 15 units (6.8%) were confirmed to contain low concentrations of opiates, benzodiazepines, stimulants, or barbiturates. Further study is needed to determine whether these drugs, which are not prohibited in donated blood by current Food and Drug Administration standards, could mediate adverse reactions in children.

Development of a liquid chromatography-tandem mass spectrometry method to address the increased utilization of umbilical cord in the assessment of in utero drug exposure.

OBJECTIVES: The method described supports the detection of drugs and drug metabolites in the assessment of in utero drug exposure. The presented method employs liquid chromatography-tandem mass spectrometry (LC-MS/MS) as an alternative to a previously validated method using liquid chromatography-time-of-flight mass spectrometry (LC-TOF/MS). A reduction in required chromatographic time and consolidation from two injections to one injection per sample was desired to reduce turnaround time while maintaining the high specificity required. DESIGN AND METHODS: Homogenized and extracted umbilical cord samples were analyzed using LC-TOF/MS and LC-MS/MS. The LC-MS/MS chromatographic method used a 3.5min gradient with an injection-to-injection time of 5min. Dynamic multiple reaction monitoring was utilized. RESULTS: A 55% reduction in total analytical time was achieved by incorporating positive and negative mode acquisition in a single injection with the LC-MS/MS (5min cycle time) compared to the LC-TOF/MS method that required two total injections (one for positive mode, one for negative mode) and a combined ~11.5min cycle time. 514 patient samples were analyzed by both methods over 20 days. Of the 260 LC-TOF/MS negative samples, 259 were LC-MS/MS negative. Inter-assay imprecision conducted over 20days using the 50% and 150% QC samples yielded $_amp_$gt;97% qualitative acceptance and an average percent deviation from the target of 12% and 21%, respectively, using a single point calibration strategy. CONCLUSIONS: In comparison to the existing LC-TOF/MS method, the LC-MS/MS method delivered the required specificity in a single injection with a 55% reduction in instrument time. Use of a single-point calibration standard and eight representative internal standards provided adequate accuracy for the quantitative assessment of quality control results with qualitative reporting of patient results.

Simplified sample preparation in the simultaneous measurement of whole blood antimony, bismuth, manganese, and zinc by inductively coupled plasma mass spectrometry.

OBJECTIVES: We developed and validated a simplified sample preparation for the analysis of antimony (Sb), bismuth (Bi), manganese (Mn), and zinc (Zn) in whole blood. This simplification included a reduction in sample volume, removal of a lengthy acidic digestion, and optimization of the internal standard. DESIGN AND METHODS: Measurement of Sb, Bi, Mn and Zn in whole blood was conducted using inductively coupled-plasma mass spectrometry. Method performance characteristics, including intra- and inter-assay imprecision, accuracy, linearity, AMR, sensitivity, carryover, sample stability and assay stability were determined in accordance with clinical laboratory standards. In addition, analytical and clinical recoveries were assessed to investigate comparability between goat blood matrix and pooled patient blood. RESULTS: Established assay performance characteristics included inter- and intra-assay imprecision <4.5% and carryover of <0.04% for all four elements, analytical measurement range of 1 to 25 µg/L (Sb and Bi), 1 to 80 µg/L (Mn), and 50 to 1500 µg/dL (Zn), limit of quantification of 1 µg/L (Sb, Bi, Mn) and 50 µg/dL (Zn) (coefficient of variation <14%), proportional bias of 0.96 and constant bias of -0.28 (Sb), 0.94 and -0.45 (Bi), 1.07 and -0.37 (Mn) and 0.96 and +18.05 (Zn) based upon repeat patient samples, proficiency testing samples, and comparison to an outside reference laboratory. CONCLUSION: This method overcomes the laborious acidic heat digestion previously used and replaces it with a simplified sample preparation involving an alkaline dilution. The method requires minimal sample preparation with the dilution of alkaline diluent and is validated to quantify Sb and Bi from 1 to 25 µg/L, Mn from 1 to 80 µg/L, and Zn from 50 to 1500 µg/dL in whole blood.

Use of synthetic urine as a matrix substitute for standard and quality control materials in the clinical assessment of iodine by inductively coupled plasma mass spectrometry.

OBJECTIVES: We developed and validated the use of synthetic urine as a matrix substitute for standard and quality control material preparation in the clinical assessment of iodine status in urine. DESIGN AND METHODS: Measurement of iodine in urine was conducted using inductively coupled-plasma mass spectrometry. Analytical and clinical recoveries were assessed to investigate comparability between synthetic urine and pooled patient urine. Method performance characteristics were determined in accordance with clinical laboratory standards. RESULTS: Established assay performance characteristics included inter- and intra-assay imprecision <10%, carryover of <0.2%, analytical measurement range of 5 to 1000µg/L, limit of quantification of 5µg/L (coefficient of variation <10%), proportional bias of 0.92 and constant bias of 8.8 in comparison to an outside reference laboratory. CONCLUSIONS: Synthetic urine is an appropriate alternative matrix for standard and quality control material preparation for the measurement of iodine in urine.

Reference interval determination for anabasine: a biomarker of active tobacco use.

Laboratory detection of nicotine exposure is important for establishing eligibility for organ transplant and elective surgery. Nicotine testing is also used to verify compliance with nicotine replacement therapies (NRT), smoking cessation programs and for life insurance purposes. Nicotine metabolites, such as cotinine and trans-3'-hydroxycotinine, are used as biomarkers of nicotine exposure. For some clinical applications, it is important to distinguish between active use of tobacco products versus NRT. Anabasine is a tobacco alkaloid that has been used as a biomarker of active tobacco use. However, the use of anabasine as an insecticide, and its presence in consumables other than nicotine products, suggests that anabasine may not be specific to tobacco use/exposure. Here, we determine the reference interval for anabasine in the urine of nonsmokers and compare it to the range of anabasine concentrations observed in the presence or absence of nicotine metabolites.