Arsenic speciation by ion-exchange chromatography with on- line determination by hydride generation: electronic modification of the D.C. plasma by photon counting

A method using L-cysteine for the determination of arsenous acid (As(III)), arsenic acid (As(V)), monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) by hydride generation was demonstrated. The instrument used was a d.c. plasma atomic emission spectrometer (OCP-AES). Complete recovery was reported for As(III), As(V), and DMAA while 86% recovery was reported for MMAA. Detection limits were determined, as arsenic for the species listed previously, to be 1.2, 0.8, 1.1, and 1.0 ngemL-l, respectively. Precision values, at 50 ngemL-1 arsenic concentration, were f.80/0, 2.50/0, 2.6% and 2.6% relative standard deviation, respectively. The L-cysteine reagent was compared directly with the conventional hydride generation technique which uses a potassium iodide-hydrochloric acid medium. Recoveries using L-cysteine when compared with the conventional method provided the following results: similar recoveries were obtained for As(III), slightly better recoveries were obtained for As(V) and MMAA, and significantly better recoveries for DMAA. In addition, tall and sharp peak shapes were observed for all four species when using L-cysteine. The arsenic speciation method involved separation by ion exchange .. high perfonnance liquid chromatography (HPLC) with on-line hydride generation using the L.. cysteine reagent and measurement byOCP-AES. Total analysis time per sample was 12 min while the time between the start of subsequent runs was approximately 20 min. A binary . gradient elution program, which incorporated the following two eluents: 0.01 and 0.5 mM tri.. sodium citrate both containing 5% methanol (v/v) and both at a pH of approximately 9, was used during the separation by HPLC. Recoveries of the four species which were measured as peak area, and were normalized against As(III), were 880/0, 290/0, and 40% for DMAA, MMAA and As(V), respectively. Resolution factors between adjacent analyte peaks of As(III) and DMAA was 1.1; DMAA and MMAA was 1.3; and MMAA and As(V) was 8.6. During the arsenic speciation study, signals from the d.c. plasma optical system were measured using a new photon-signal integrating device. The_new photon integrator developed and built in this laboratory was based on a previously published design which was further modified to reflect current available hardware. This photon integrator was interfaced to a personal computer through an AID convertor. The .photon integrator has adjustable threshold settings and an adjustable post-gain device.

Cabinet Card by John B. Cook, Photographer, Toronto [n.d.]

Two young African Canadian girls are the subject of this undated cabinet card photograph by John B. Cook, of Toronto. The address listed on the company stamp, which appears in gold lettering at the bottom of the card, is 191 and 193 Yonge [St.] Toronto. The original photo was over-exposed and faded, so image adjustments have been made for clarification purposes. This photograph was in the possession of Iris Sloman Bell, of St. Catharines, Ontario. It is possible these two girls are relatives of the Sloman and Bell families. Relatives of the Sloman - Bell families include former American slaves who settled in Canada.John B. Cook is listed as being a photographer -- and a hotelier -- in Toronto from 1879-1898. Source: Phillips, Glen C. The Ontario photographers list (1851-1900). Sarnia: Iron Gate Publishing Co., 1990.

Letter - John P. Weston Co., to S.D. Woodruff

A letter (printed) from the John P. Weston Co. of Rochester, New York to S.D. Woodruff regarding an Italian marble headstone with Julia Ann Woodruff raised at the top, Nov. 15, 1901.

Opinion Regarding the Estate of S.D. Woodruff

An opinion regarding the estate of S.D. Woodruff. This is in regard to the liability of the estate to pay succession duties in Ontario upon certain American bonds and securities in the City of New York. This is a 6 page printed document prepared by Dewart, Young and Maw - February 7, 1905.

Estate of S.D. Woodruff in Account with H.H. Collier

The estate of S.D. Woodruff in account with H.H. Collier. This contains 1 1/2 printed pages listing expenses to be paid to Johnson Clench for copy of depositions, 1906-1907.

Almanac of S.D. Woodruff of St. Catharines

Almanac of S.D. Woodruff of St. Catharines (soft cover) containing records of items sold to various people, 1858-1866.

Canadian Bank of Commerce (vinyl cover), St. Catharines bank book of Welland D. Woodruff Esq.

Canadian Bank of Commerce (vinyl cover), St. Catharines bank book of Welland D. Woodruff Esq., 1915-1917.

List of inventory of goods in the dwelling of S.D. Woodruff of St. Catharines

List of inventory of goods (6 pages, handwritten) in the dwelling of S.D. Woodruff of St. Catharines. This list was examined by William Walker on Oct. 30, 1862 and compiled on Oct. 27, 1862.

List of inventory of goods in the dwelling of S. D. Woodruff, Ontario Street, St. Catharines

List of inventory (5 pages, handwritten) of goods in the dwelling of S. D. Woodruff, Ontario Street, St. Catharines, n.d.

List of abstracts (2 pages, handwritten) stating the cost of S.D. Woodruff dwelling and barns

List of abstracts (2 pages, handwritten) stating the cost of S.D. Woodruff dwelling and barns, January, 1878.

Memorandum of S.D. Woodruff’s property on Ontario Street

Memorandum (1 page, handwritten) of S.D. Woodruff’s property on Ontario Street, Jul. 25, 1901.

Letter to the Estate of W.D. Woodruff from S. Mitchell, secretary of the Lincoln Paper Mills Company

Letter to the Estate of W.D. Woodruff from S. Mitchell, secretary of the Lincoln Paper Mills Company (1 page, printed). This is a notice of the 43rd annual meeting of the shareholders of the Lincoln Paper Mills Company, Limited. This is accompanied by an envelope, Feb. 7, 1921.

Sketch of the ship "Jane C. Woodruff"

A black and white copy of a sketch of the ship "Jane C. Woodruff". This appears to have been in a scrapbook. There is a slight tear which affects the picture slightly. [The Jane C. Woodruff was a barquentine ship built in St. Catharines in 1866 by Lewis Shikeluna. The ship belonged to John Battle who was an associate of Samuel D. Woodruff. She was named in honour of Samuel and his wife, Jane Caroline. She originated as a square timber trade boat before being converted into a 3 masted schooner. She collided with the "Mary Battle" in a snow squall in Georgian Bay. The ship passed out of existence in 1902].