Dataset Information

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product.

ABSTRACT: Small specimen volume and high sample throughput are key features needed for routine methods used for population biomonitoring. We modified our routine eight-probe solid phase extraction (SPE) LC-MS/MS method for the measurement of five folate vitamers [5-methyltetrahydrofolate (5-methylTHF), folic acid (FA), plus three minor forms: THF, 5-formylTHF, 5,10-methenylTHF] and one oxidation product of 5-methylTHF (MeFox) to require less serum volume (150 ?L instead of 275 ?L) by using 96-well SPE plates with 50 mg instead of 100 mg phenyl sorbent and to provide faster throughput by using a 96-probe SPE system. Total imprecision (10 days, two replicates/day) for three serum quality control pools was 2.8-3.6% for 5-methylTHF (19.5-51.1 nmol/L), 6.6-8.7% for FA (0.72-11.4 nmol/L), and ?11.4% for the minor folate forms (<1-5 nmol/L). The mean (±SE) recoveries of folates spiked into serum (3 days, four levels, two replicates/level) were: 5-methylTHF, 99.4 ± 3.6%; FA, 100 ± 1.8%; minor folates, 91.7-108%. SPE extraction efficiencies were ?85%, except for THF (78%). Limits of detection were ?0.3 nmol/L. The new method correlated well with our routine method [n = 150, r = 0.99 for 5-methylTHF, FA, and total folate (tFOL, sum of folate forms)] and produced slightly higher tFOL (5.6%) and 5-methylTHF (7.3%) concentrations, likely due to the faster 96-probe SPE process (1 vs. 5 h), resulting in improved SPE efficiency and recovery compared to the eight-probe SPE method. With this improved LC-MS/MS method, 96 samples can be processed in ~2 h, and all relevant folate forms can be accurately measured using a small serum volume.

SUBMITTER: Fazili Z

PROVIDER: S-EPMC5326548 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product.

Fazili Zia Z Whitehead Ralph D RD Paladugula Neelima N Pfeiffer Christine M CM

Analytical and bioanalytical chemistry 20130306 13

Small specimen volume and high sample throughput are key features needed for routine methods used for population biomonitoring. We modified our routine eight-probe solid phase extraction (SPE) LC-MS/MS method for the measurement of five folate vitamers [5-methyltetrahydrofolate (5-methylTHF), folic acid (FA), plus three minor forms: THF, 5-formylTHF, 5,10-methenylTHF] and one oxidation product of 5-methylTHF (MeFox) to require less serum volume (150 μL instead of 275 μL) by using 96-well SPE pla ...[more]

PMID: 23462981

Similar Datasets

Project description:Exposure to natural food contaminants during infancy may influence health consequences later in life. Hence, breast milk may serve as a vehicle to transport these contaminants, including mycotoxins, from mothers to their infants. Analytical methods mostly focused on single exposures in the past, thus neglecting co-occurrences and mixture effects. Here, we present a highly sensitive multi-biomarker approach by a sophisticated combination of steps during sample preparation including a Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction followed by a solid phase extraction (SPE) cleanup and utilizing stable isotopes for compensating challenging matrix effects. The assay was validated in-house, reaching limits of detection (LOD) for all 34 analytes in the range of 0.1 to 300 ng/L with satisfying extraction efficiencies (75-109%) and stable intermediate precisions (1-18%) for most analytes. Compared to a similar multi-mycotoxin assay for breast milk, LOD values were decreased by a factor of 2-60x enabling the assessment of chronic low-dose exposures. The new method was applied to a small set of Nigerian breast milk samples (n = 3) to compare results with already published data. Concentration levels of samples that were found to be contaminated before could be confirmed. In addition, other mycotoxins were determined in all three samples, for example the newly investigated alternariol monomethyl ether (AME) was found for the first time in this biological fluid at concentrations up to 25 ng/L. Moreover, in a pooled Austrian sample obtained from a milk bank, trace amounts of multiple mycotoxins including AME (1.9 ng/L), beauvericin (5.4 ng/L), enniatin B (4.7 ng/L), enniatin B1 (<LOQ), ochratoxin A (<LOQ) and the estrogenic zearalenone (<LOQ) confirmed co-occurrence and exposure even in a country with high food safety standards. In conclusion, the method facilitates the determination of mycotoxins at ultra-trace levels in breast milk, enabling the generation of occurrence data necessary for comprehensive co-exposure assessment.

Project description:Data quality in global metabolomics is of great importance for biomarker discovery and system biology studies. However, comprehensive metrics and methods to evaluate and compare the data quality of global metabolomics data sets are lacking. In this work, we combine newly developed metrics, along with well-known measures, to comprehensively and quantitatively characterize the data quality across two similar liquid chromatography coupled with mass spectrometry (LC-MS) platforms, with the goal of providing an efficient and improved ability to evaluate the data quality in global metabolite profiling experiments. A pooled human serum sample was run 50 times on two high-resolution LC-QTOF-MS platforms to provide profile and centroid MS data. These data were processed using Progenesis QI software and then analyzed using five important data quality measures, including retention time drift, the number of compounds detected, missing values, and MS reproducibility (2 measures). The detected compounds were fit to a γ distribution versus compound abundance, which was normalized to allow comparison of different platforms. To evaluate missing values, characteristic curves were obtained by plotting the compound detection percentage versus extraction frequency. To characterize reproducibility, the accumulative coefficient of variation (CV) versus the percentage of total compounds detected and intraclass correlation coefficient (ICC) versus compound abundance were investigated. Key findings include significantly better performance using profile mode data compared to centroid mode as well quantitatively better performance from the newer, higher resolution instrument. A summary table of results gives a snapshot of the experimental results and provides a template to evaluate the global metabolite profiling workflow. In total, these measures give a good overall view of data quality in global profiling and allow comparisons of data acquisition strategies and platforms as well as optimization of parameters.

Dataset Information

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product.

Publications

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets