PMID- 27936596
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180927
LR  - 20180927
IS  - 1520-6882 (Electronic)
IS  - 0003-2700 (Linking)
VI  - 89
IP  - 1
DP  - 2017 Jan 3
TI  - Challenges Determining the Correct Deposition Order of Different Intersecting 
      Black Inks by Time-of-Flight Secondary Ion Mass Spectrometry.
PG  - 759-766
LID - 10.1021/acs.analchem.6b03411 [doi]
AB  - The distinction of different inks and determination of their deposition order are 
      important forensic tasks when evaluating questioned documents. Time-of-flight 
      secondary ion mass spectrometry (ToF-SIMS) has received attention for these tasks 
      due to the technique's nondestructive nature, rich mass spectral information, 
      ability to provide chemical images, and excellent surface sensitivity. Prior 
      literature results demonstrate the ability of ToF-SIMS to differentiate between 
      many varieties of blue ballpoint pens and to determine the correct deposition 
      order for selected ink intersections. The current work therefore sought to 
      further study the intersections of different black inks. Three black pens were 
      initially tested and were successfully distinguished. However, interesting 
      phenomena were observed where certain inks dominated over others, causing 
      distinctly incorrect conclusions to be made regarding ink deposition order. To 
      explore whether these incorrect results could be corrected, different primary 
      ions (Bi(3)(+), Bi(3)(+2), and Ar(1000)(+)) were used and positive and negative 
      secondary ions were evaluated. In data analysis, restriction of the mass range 
      was considered and different multivariate analysis techniques, principal 
      component analysis (PCA) and multivariate curve resolution (MCR), were performed 
      on the secondary ion images and spectra from selected regions of interest. Issues 
      regarding incorrect apparent order of deposition persisted through the variation 
      of all these parameters. In addition to ink differentiation, and deposition 
      order, evidence of ink aging was also observed. These results raise several 
      questions to be answered regarding the widespread use of ToF-SIMS for forensic 
      ink analysis.
FAU - Goacher, Robyn E
AU  - Goacher RE
AUID- ORCID: 0000-0001-7863-4888
AD  - Department of Biochemistry, Chemistry and Physics, Niagara University , 5795 
      Lewiston Road, Lewiston, New York 14109, United States.
FAU - DiFonzo, Lauren G
AU  - DiFonzo LG
AD  - Department of Biochemistry, Chemistry and Physics, Niagara University , 5795 
      Lewiston Road, Lewiston, New York 14109, United States.
FAU - Lesko, Kathleen C
AU  - Lesko KC
AD  - Department of Biochemistry, Chemistry and Physics, Niagara University , 5795 
      Lewiston Road, Lewiston, New York 14109, United States.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20161212
PL  - United States
TA  - Anal Chem
JT  - Analytical chemistry
JID - 0370536
EDAT- 2016/12/13 06:00
MHDA- 2016/12/13 06:01
CRDT- 2016/12/13 06:00
PHST- 2016/12/13 06:00 [pubmed]
PHST- 2016/12/13 06:01 [medline]
PHST- 2016/12/13 06:00 [entrez]
AID - 10.1021/acs.analchem.6b03411 [pii]
AID - 10.1021/acs.analchem.6b03411 [doi]
PST - ppublish
SO  - Anal Chem. 2017 Jan 3;89(1):759-766. doi: 10.1021/acs.analchem.6b03411. Epub 2016 
      Dec 12.