Screening method for extractable organically bound fluorine (EOF) in river water samples by means of high-resolution-continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS).

The introduction of fluorine into organic molecules leads to new chemical/physical properties. Especially in the field of pharmaceutical as well as technical applications, fluorinated organic substances gain in importance. The OECD identified and categorized 4730 per- and polyfluoroalkyl substances-related CAS numbers. Thus, an increasing release of fluorinated compounds into the environment is expected. In particular, perfluorinated compounds often show higher environmental stability leading to the risk of bioaccumulation. Polyfluorinated compounds undergo decomposition; thus, further possible fluorine species occur, which may exhibit different toxic/chemical properties. However, current target methods based on, e.g., HPLC/MS-MS, are not applicable for a comprehensive screening of fluorinated substances as well as assessment of pollution. Thus, within this work, a sum parameter method for quantitative determination of extractable organically bound fluorine (EOF) in surface waters was developed. The method is based on solid-phase extraction (SPE) for extraction of fluorinated compounds as well as separation of interfering inorganic fluoride in combination with high-resolution-continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) for organic fluorine quantification. Upon optimization of the SPE procedure (maximum concentration of extractable organic fluorine), enrichment factors of about 1000 were achieved, allowing for highly sensitive fluorine detection. HR-CS GF MAS allows for selective fluorine detection upon in situ formation of a diatomic molecule ("GaF"). Next to a species-unspecific response, limits of detection in the low nanogram per liter range (upon enrichment) were achieved. Upon successful method development, surface water samples (rivers Moselle and Rhine) were analyzed. Furthermore, a sampling campaign along the river Rhine (from the south-close to the French border; to the north-close to The Netherlands border) was conducted. EOF values in the range of about 50-300 ng/L were detected. The developed method allows for a fast and sensitive as well as selective/screening detection of organically bound fluorine (EOF) in surface water samples, helping to elucidate pollution hotspots as well as discharge routes. Graphical abstract A solid phase extraction (SPE) HR-CS GF MAS screening method was developed for the quantitative analysis/screening of extractable organically bound fluorine (EOF) in river water samples. Highly sensitive EOF analysis (low ppq range) was obtained upon SPE and HR-CS GF MAS analysis. Sampling campaign along the river Rhine was conducted.

High-resolution continuum source graphite furnace molecular absorption spectrometry compared with ion chromatography for quantitative determination of dissolved fluoride in river water samples.

In addition to beneficial health effects, fluoride can also have adverse effects on humans, animals, and plants if the daily intake is strongly elevated. One main source of fluoride uptake is water, and thus several ordinances exist in Germany that declare permissible concentrations of fluoride in, for example, drinking water, mineral water, and landfill seepage water. Controlling the fluoride concentrations in aqueous matrices necessitate valid and fast analytical methods. In this work an alternative method for the determination of fluoride in surface waters based on high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) was applied. Fluoride detection was made possible by the formation of a diatomic molecule, GaF, and detection of characteristic molecular absorption. On HR-CS-GFMAS parameter optimization, the method was adapted to surface water sample analysis. The influence of potential main matrix constituents such as Na+, Ca2+, Mg2+, and Cl- as well as surface water sampling/storage conditions on the molecular absorption signal of GaF was investigated. Method validation demonstrated a low limit of detection (8.1 µg L-1) and a low limit of quantification (26.9 µg L-1), both sufficient for direct river water sample analysis after 0.45-µm filtration. The optimized HR-CS-GFMAS method was applied for the analysis of real water samples from the rivers Rhine and Moselle. For method validation, samples were also analyzed by an ion chromatography (IC) method. IC and HR-CS-GFMAS results both agreed well. In comparison with IC, HR-CS-GFMAS has higher sample throughput, a lower limit of detection and a lower limit of quantification, and higher selectivity, and is a very suitable method for the analysis of dissolved fluoride in river water. Graphical abstract High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) was applied for the quantitative analysis of dissolved fluoride in river water samples from the Rhine and the Moselle. Fluoride detection was made possible by the addition of Ga for GaF formation and analysis of characteristic molecular absorption at 211.248 nm. Good agreement between HR-CS-GFMAS and ion chromatography (IC) results was obtained. In comparison with IC, HR-CS-GFMAS had a faster sample throughput and lower limit of detection and limit of quantification.

Frequency of sentinel lymph node metastases in patients with favorable breast cancer histologic subtypes.

BACKGROUND: The need for axillary nodal staging in favorable histologic subtypes of breast cancer is controversial. METHODS: Patients with clinical stage T1-2, N0 breast cancer were enrolled in a prospective, multi-institutional study. All patients underwent sentinel lymph node (SLN) biopsy followed by completion level I/II axillary dissection. RESULTS: SLN were identified in 3,106 of 3,324 patients (93%). Axillary metastases were found in 35% and 40% of patients with infiltrating ductal carcinoma and infiltrating lobular carcinoma, respectively. Among tumor subtypes, positive nodes were found in 17% of patients with pure tubular carcinoma, 7% of patients with papillary cancer, 6% of patients with colloid (mucinous) carcinoma, 21% of patients with medullary carcinoma, and 8% of patients with DCIS with microinvasion. CONCLUSIONS: Patients with favorable breast cancer subtypes have a significant rate of axillary nodal metastasis. Axillary nodal staging remains important in such patients; SLN biopsy is an ideal method to obtain this staging information.

The effect of prior breast biopsy method and concurrent definitive breast procedure on success and accuracy of sentinel lymph node biopsy.

BACKGROUND: It has been suggested that sentinel lymph node (SLN) biopsy for breast cancer may be less accurate after excisional biopsy of the primary tumor compared with core needle biopsy. Furthermore, some have suggested an improved ability to identify the SLN when total mastectomy is performed compared with lumpectomy. This analysis was performed to determine the impact of the type of breast biopsy (needle vs. excisional) or definitive surgical procedure (lumpectomy vs. mastectomy) on the accuracy of SLN biopsy. METHODS: The University of Louisville Breast Cancer Sentinel Lymph Node Study is a prospective multi-institutional study. Patients with clinical stage T1-2, N0 breast cancer were eligible. All patients underwent SLN biopsy and completion level I/II axillary dissection. Statistical comparison was performed by chi(2) analysis. RESULTS: A total of 2206 patients were enrolled in the study. There were no statistically significant differences in SLN identification rate or false-negative rate between patients undergoing excisional versus needle biopsy. The SLN identification and false-negative rates also were not statistically different between patients who had total mastectomy compared with those who had a lumpectomy. CONCLUSIONS: Excisional biopsy does not significantly affect the accuracy of SLN biopsy, nor does the type of definitive surgical procedure.