Pesticide residue grade acetonitrile (99.5%%) was purchased from BDH, England.
Solvents employed were nanograde isooctane (Mallinckrodt, Paris, KY), trace environmental analysis grade hexane (99.9%), methanol (99.9%), dichloromethane (99.9%), pesticide residue grade acetone (99.9%), and toluene (99.9%) (Burdick & Jackson, Muskegon, MI).
Bisphenol A-d16 (>99%D), toluene (glass distilled), potassium carbonate (ACS grade), bisphenol A (99%), isooctane (pesticide-residue grade), MTBE (methyl t-butyl ether, 99.9%), K2HPO4 (ACS), Na2SO4 (anhydrous, ACS grade), l-pentanol (99%) and dodecane (99%) were purchased from Sigma-Aldrich (Oakville, ON, Canada).
In the surgical specimen, the classification of histological response proposed by Sinn et al. [ 22] was used (grade 0: no effect; grade I: resorption and tumour sclerosis; grade II: minimal focal invasive residues of ≤ 5 mm; grade III: only non-invasive tumour residues; grade IV: no viable tumour cell detectable).
We evaluated the regression grade of the tumor compartment according to Sinn et al. (grade 0: no effect, grade 1: resorption and tumor sclerosis, grade 2: minimally focally invasive residues of 5 mm or smaller, grade 3: only non-invasive tumor residues, grade 4: no viable tumor cell detectable) [ 22].
Given the reasonable overall recoveries, the main reason for the low concentrate grades could have been the very low grade of the feed material, which was two to three times less enriched in metals than the average micaceous residues grades.
HPLC-grade sulphuric acid as well as HPLC/GC residue-grade acetone, dichloromethane (DCM), hexane and toluene were purchased from EMD (Ottawa, ON, Canada).
The Twillwipes were pre-cleaned and dampened with 4.0 mL of pesticide residue analysis grade isopropanol before use.
All the solvents used for the extraction and cleanup procedures were residue-analysis grade.
All the organic solvents and water used for the extraction and cleanup procedures were residue-analysis grade.
The current paper analysed the test reports from 1223 HTF systems and showed that, on average, the carbon residue for food grade HTF was lower than non-food grade HTF.
